Decide on Method of Construction

Place and position are key components of the practice of energy efficiency and green building.

How people and products get to and from the site affects the building position and its occupants' energy efficiency. Choosing a venue that provides transport options and a range of destinations in the vicinity has several benefits: 

• By shortening the distance people must travel and making it easier to walk, bike, or take public transportation, the site location protects air and water quality. 
• Building on or near already-established sites protects open space, farmland, and natural land. 
• Utilising existing facilities saves money and energy. 

 

A location-efficient and well-positioned building is well-connected to and near amenities. 

These are job centres, stores, restaurants, colleges, and utilities in the wider area. A site with good transport links to the rest of the area will draw companies who want consumers and employees to have easier access and people who want to be able to get more jobs. 

Location-efficient and well-positioned buildings are also already covered by infrastructure in previously established areas.

The need for new highways, power poles, water pipes, and other facilities is minimised by building in previously developed areas. By reusing and renovating existing buildings, it can also spur community revitalisation. It is possible to transform historic houses, abandoned land, brownfields, and grey fields into energy-efficient and green places that benefit the local economy and enhance the character of the city.

Environmental factors that affect building

The ecosystem is in a continual state of modification, both natural and anthropogenic. You can define the changes that are observed as those closely aligned with the evolutionary progress of the planet and those representing the heterogeneity of the factors influencing it. 

It can be observed that those environmental factors which influence buildings are all variable for the second category of changes. These variables include air temperature, solar radiation, humidity, wind, rainfall, air pollution, noise, etc. More precisely, their physical values (of scalar or vector type) represent fluctuations in many of their aspects. In the case of some of the aforementioned variables, these variations display a wide range of values that may differ between negative and positive effects from time to time, such as air temperature, humidity, solar radiation and wind speed. In the case of other variables, the variations vary from zero to (usually) negative, such as emissions and ambient noise. The frequency with which the environmental variables influencing buildings differ is also of interest beyond their strength aspect. Periodicity is an attribute that describes almost all meteorological variables. It is also normal for the same phenomenon to observe several levels of periodic cycles (daily 
or yearly cycles etc.). The same goes for air pollution, especially in urban areas. Randomness is not removed, however; according to which certain variables occur in a random fashion. A typical example is a storm or an incident of pollution. At this point, it is important to stress the fact that environmental factors influence the built environment through different processes at various levels. For example, the wind may act as a ventilation medium; for natural cooling; for dispersion of pollution; for thermal exchange at the surface of the building shell and as a factor involved in structural integrity. Such a factor can be positive at some levels and detrimental at others with such a wide range of consequences. This feature makes the successful handling of that aspect quite a challenge. 

The variations in the values of environmental variables have a direct effect on how the systems built in the buildings operate to monitor their impact. The way the systems respond to variable conditions, on the other hand, is critical to their performance. If they are tailored to address the effects of the prevailing factors, passive systems are effective. On the other hand, active systems show more versatility in their reaction to the fluidity of the effect on the environment. Their behaviour represents the circumstances and can be articulated in several different ways, such as changing shape, geometry, or qualitative features. In order to maximise regulation of daylight and solar heat gains, dynamic louvers are a good example of a device that 'behaves' according to the prevailing conditions, responding to them. The more adaptable these systems are to several situations, the more effective they are. 

Systems promoting the environmental and energy behaviour of buildings are built to avoid and encourage detrimental environmental influences. In temperate climates where major environmental conditions present variations that have dramatically different impacts on buildings, this criterion determines the peculiarities of sustainable design. Indeed, though the control of these variables is one-dimensional in cold and warm climates; this is not so in temperate climates as these variables are sometimes positive in their effects and should be preferred and sometimes negative and should be avoided. As an example, mention may be made of solar heat gain that is generally welcome in cold climates and unwelcome in warm climates; it is welcome in the winter and unwelcome in the summer in temperate climates. 

The comments referred to above suggest the expediency of a separate group of instruments for the sustainable design and construction of buildings in temperate-climate regions with common features of variable environmental impact management. With the former being simpler and more elegant in their service, these instruments may be either passive or active. However, it is common to see more than one method in buildings in temperate climates and even, more broadly, architectural practices that are intended to handle various (often contradictory) effects of the same environmental factor. Solar gain and solar shading systems can co-exist in the same house, for example. This phenomenon does not occur in other climate zones, as a result of the large variability of environmental impacts.

Climatic conditions affecting building

When you work to reduce energy costs by paying attention to the processes in your facility, bear in mind that the amount of energy you use can be influenced by a variety of factors outside your control. Your job is to preserve the ideal interior conditions, but the external factors are beyond your influence, such as climate, topography, and building orientation. 

Climate conditions can affect the option of building orientation, structure, and envelope of a building designer, as well as the energy needs of a building for heating, cooling, ventilation, and, to a lesser extent, lighting. Just like environmental factors, climatic conditions affect a building that is not well-positioned and well-located.

Variations in temperature 

The size and choice of mechanical and electrical devices can be influenced by daily or seasonal temperature fluctuations, as well as peak temperatures. Daytime differences are often a product of a particular building site’s topography. For instance, due to numerous temperature air masses moving up and down the mountainside, a building situated at the base of a mountain is likely to have a wide range of temperature fluctuations. 

In desert regions and other areas that have a high percentage of clear skies and sunlight, significant variations also occur. During the day, a significant amount of sunlight heats up the ground. This heat is lost at night because there are few clouds to trap the heat near the ground. 

While such large variations may require the installation of larger electrical and mechanical equipment than would otherwise be necessary, they can also provide an opportunity to use a heating and cooling storage device that can minimise energy usage, such as an active or passive solar heating system. 

Amount of sunlight

Another climatic factor that can impact the energy consumption of a building is the amount of sunlight a building receives. Indeed, the annual heating energy consumption of two buildings with similar temperatures but varying amounts of sunlight in different geographic areas can vary by more than 30 percent. 

To assess the amount of sunlight striking a building at various periods of the year, monthly solar loads must be accurately measured. Some solar controls include glazed areas' internal or external shading; outdoor cooling ponds; and solar panels for heating or cooling air, heating hot water in homes, or using photovoltaic cells to generate electricity. These controls can be used so that a building maximises the heating power of sunlight during the winter and minimises it during the summer. 

It is also important to consider the colour of external surfaces. Dark colours promote heat absorption and can be used on the north walls or roofs in cold climates, while light colours are best used on roofs in warm climates to reflect sunlight. 

Path and wind velocity 

Wind speed and direction can impact a building's strategic orientation, structure, and envelope, as well as its energy consumption. The film of still air surrounding and insulating a building is disrupted by wind, thus increasing heating and cooling loads. In addition, on wet building surfaces, wind helps moisture evaporate, allowing the surface to cool to below the ambient air temperature. 

The north and west sides of a building in the northern hemisphere are exposed to the strongest winds. To mitigate air leakage around doors, windows, and other openings, buildings should have their most vulnerable areas, such as entrances and glazed areas, located away from prevailing winds. 

It should be adequately protected from the wind if an entrance faces to the north or west. If not, during the winter months, a combination of high winds and low temperatures may cause elevated infiltration, resulting in high energy consumption. 

While high winds often result in increased energy consumption, if the natural cooling properties of the wind are harnessed and used throughout a building, they could decrease consumption in some areas. 

Snowfalls

Snow cover on the roofs of low-rise buildings will serve as a natural insulator for buildings built to maintain it in areas where snowfall is heavy and persistent during the winter months. In addition, reflecting ground snow on adjacent low buildings will raise the degree of a building's illumination and increase the efficiency of solar collectors, thus reducing the need for artificial lighting. 

Topography 

The topography of the site of a building, which includes natural and man-made features, can affect its energy consumption by reducing or raising the effects of previously discussed climatic influences. For example, the trees surrounding a building may decrease the intensity of sunlight or decrease the speed of wind. If situated close enough to the house, trees in the surrounding building area may also alter the outdoor humidity. 

Orientation and design of buildings 

The way a building faces and its design determines how the use of building energy is influenced by climatic and topographic factors. By affecting the amount of ambient sunlight that can be used for indoor illumination, orientation affects the power needed for lighting systems. Configuration impacts gains or losses in sun. For example, a building with a circular configuration has less surface area than other shapes of construction and thus experiences less heat gain or loss than other configurations with equivalent floor space. A building with a square form has less surface area than a rectangular one and less heat gain or loss is also experienced. 

As you work to establish an efficient energy management program, considering the demand for building systems and the building envelope, knowing the external factors that impact interior building conditions can assist you.

 

Thermal energy

Most thermal power plants are powered by steam. Water is usually heated into steam and guided through a turbine's blades, causing it to spin. The turbine is normally connected to an electric generator or, like turning a ship propeller, is used for other work. 

The steam is cooled and condensed back into liquid form after going through the turbine before being returned to the heat source, where it will be transformed to steam again. A wide variety of fuels are used by power plants to heat liquids into steam. Natural gas, coal, uranium (nuclear), diesel, oil and biomass materials are some of the more common fuels. 

Wide industrial facilities used to produce electricity are most thermal plants.

Thermal energy systems convert heat energy into work. The thermal energy efficiency represents the heat energy fraction that becomes valuable work.

The thermal energy efficiency is expressed by the thermal efficiency symbol, and can be calculated using the following equation: 

η=W/QH   

• The useful job is W. 
• The cumulative input of heat energy from the hot source is QH.  

 
Often, due to practical limitations, thermal energy systems work at about 30 percent to 50 percent energy efficiency. According to the Second Law of Thermodynamics, it is difficult for heat engines to reach 100 percent thermal efficiency. This is impossible because some waste heat is always produced in a thermal energy system. Although full efficiency in a heat engine is unlikely, there are several ways to improve the overall efficiency of a system. 

For example, if the input (QH) is 200 joules of thermal energy as heat and the motor does 80 J of work (W), then the energy efficiency is 80J/200J, which is 40% energy efficiency. 

This same result can be obtained by calculating the engine's waste heat. For instance, if 200 J is put into the engine and 120 J of waste heat is detected, then 80 J of work must have been done, giving an efficiency of 40 percent.

Heating and cooling 

In most homes, space conditioning is the chief contributor to the use of electrical energy. Making your home better at maintaining coolness ('coolth') and warmth will help make living in your home both easier and more affordable. 

You will probably spend more energy on heating if you live in a cold climate, whereas those in warmer climates will spend more on cooling. In Australia, on average, heating contributes more than cooling to total energy consumption in one year. This is partly because, compared to warmer ones like the Northern Territory, a large percentage of Australia's population lives in colder regions like Victoria. In addition, heating appliances are usually much less energy efficient than refrigeration appliances. According to DEWHA, at 40% of household energy use, heating and cooling are together the largest energy user in the average Australian home. However, since most home heating uses gas, heating is responsible for a lower proportion of energy bills and greenhouse gas emissions than its share of energy use suggests.¹³

Steps for improving the conditioning of a room

Step 1: Checking of facilities 

Spending funds to replace operational but inefficient equipment is not a top priority for most households. To confirm that everything is working properly, it makes sense to look at what is already present in the building. Check for corrosion signs, remove any debris accumulation on or around the machinery, and ensure that all filters are clean. 

If equipment is more than 10-15 years old or if it needs frequent repairs, consider replacing it, as there is a good chance that it may not run as efficiently as it did when it was first purchased. In addition, improvements in standards of efficiency mean that newer units usually do their jobs better than older ones. Not only can replacement save down the line on repair costs; it can also help save a substantial amount on total energy consumption and bill. 
 

Step 2: Check the building for drafts & insulation 

Leaks from the air: 

Drafts cause up to 25 percent of their heat to be lost to the building. It could save up to a fifth of the total energy consumption by sealing drafts around the building. 

Try to choose a windy day and shut down all the doors and windows around the building. Take a walk around the building and try to notice any light, drafts or gaps seeping through. To feel for air leaks, you can wet your arms. You can also hold incense or a candle and watch the movement of smoke. 

In general, pay close attention to the following things: 

• junctions between construction materials (outside) 
• doors and windows 
• outlets for electricity 
• baseboard and flooring 
• any additional openings around the home 
• Gaps can be sealed by weather-proofing strips, caulking or fillers, depending on the area of the leak. 

 

Insulation

The presence of insulation in the walls and the roof cavity can have a major impact on the heating and cooling needs of the building. Insulation slows the heat movement in and out of the building envelope, reducing the need to heat or cool in the first place significantly. 

The attic floor might not have the recommended minimum amount of insulation, depending on the age of the building. If you are unsure, consider getting an evaluation. 

To minimise heat transfer in and out of the building, consider installing insulation for walls, floors, and pipes. 

Step 3: Check your habits for heating & cooling 

Once you have made sure that the efficiency of the heating/cooling system is working and that the building does not bleed heat through gaps and uninsulated spaces, it is time to look at the second efficiency component: how you use the devices yourself. 
 
Below are some tips for minimising heating & cooling loads at home, in addition to dressing right for the circumstances (rugging up in the cold and vice versa for the heat). 

Summer/warm climate 

• Set the temperature sensibly: by setting the AC on full blast, you will 'overcool' the building. Each degree of heating required results in increasingly large amounts of energy. 
• Cool only the rooms needed: by closing doors, minimise the total area that requires heating. 
• Use shade to cool the home: when the sun shines down, draw window blinds. 
• Use fans to support cooling: Compared to AC units, fans require much less energy consumption, but can often have a significant impact on comfort levels. 

 

Winter/cool atmosphere 

• Set the temperature sensibly: Every additional degree of heating requires more energy, as with cooling a hot house, and will further rack up the costs. 
• Heat only the spaces needed: try to avoid heating unoccupied spaces, as with cooling. 
• Use the sun to heat the building; open blinds on those that receive direct light so that you can let the sun in through the windows as much as possible throughout the day. 

Companion fans

Fans also increase the operation of other heating & cooling devices in addition to being an efficient, low-cost option for beating the heat on a moderately hot day, saving a few dollars n the process. 

Refrigeration

While the AC is on, running a ceiling or pedestal fan helps move cool air around the space. This should help to keep the thermostat of the AC down by a few degrees, allowing the machine to operate at a lower cost overall. 

Heating 

If ceiling fans are switched into 'winter'/reverse mode (where blades rotate in the opposite direction, sucking air up instead of pushing it down), ceiling fans can help to keep a room feeling warm. In doing so, the cool air is mixed at floor level with the warmer air that usually sits at ceiling level. The ceiling fan ‘evens out’ the overall feeling of warmth in the room by doing so. 

Heat pumps vs air conditioners: 

The main difference between a standard air conditioner and a heat pump (also known as a space heating/cooling reverse cycle air conditioner) is that a standard AC unit can only move heat in one direction (from inside the house to outside) while a heat pump's direction is reversible. 

This means that for heating and cooling, you can use a heat pump, whereas an AC unit can only be used for cooling. Heat pumps tend to be more costly than air conditioners because of their greater versatility. 

The heat pump's heating efficiency is limited by the climate; many units will not function in colder regions when the temperature drops to about 5° C. This implies that they are not suitable for places with longer, colder winters where temperatures get so low on a regular basis. To determine which ones - if any - could work in a region, check the specifications of individual units. 

Cooling: If you live in a region where a heat pump is a viable option, if you do not already have another major heating appliance (such as a wood or gas furnace) in place, provided it fits your budget, it may make sense to get a heat pump. 

Choosing the right equipment 

You are bound to buy some new heating & cooling equipment at some point, whether you are just moving into a new home and starting from scratch or have been in the same place for over a decade. It is important to know the pros & cons of each option when that time comes: fans, evaporative coolers, heaters, and air conditioners. 

Air conditioners and heat pumps 

The popular options for keeping a home feeling cosy are air conditioners and reverse-cycle air conditioners (aka heat pumps). While air conditioners are good for cooling, heat pumps will both heat and cool a room during the summer months (if it is not too cold outside). 

Systems split 

Make sure it is the correct size for the building when choosing an air-conditioner. If you want to cool just one or two rooms within the home, split systems are more suitable, while ducted systems are the choice for an entire home. Clean air is pumped in by both systems, meaning you do not have to keep windows or doors open for circulation. 

The air conditioners of the split system come in two 'parts': 

• The condenser (or compressor) in or out of the home that moves warm air. This element sits outside the home. 
• The outlet, which is the point where the air is shared with the condenser in the home. In general, one or two outlets are in the home. 

Standard vs split systems inverter 

Split-inverter systems operate more efficiently than standard systems. Standard systems operate at only one intensity until the space reaches a set temperature, at which point it switches off. As the temperature fluctuates above and under the target temperature, this on/off/on cycle repeats repeatedly during operation. 

On the other hand, inverter systems can operate at variable speeds, run at a high capacity until the set temperature has been reached, and then switch to a lower capacity to maintain that temperature. This means fewer fluctuations in energy and higher energy efficiency. 

To compare energy efficiency between models, make sure that you look at the star rating system and kWh consumption. 

Portable air conditioners & window 

Window-mounted and portable air conditioners do the same work as a split system, but inside the unit are both the condenser and the outlet. They are usually cheaper to buy and install than split system ACs, but for similar-sized units, they are also less efficient.

Innovative sustainable heating and cooling technologies

Many buildings all over Europe and some parts of the world opt for a surface heating and cooling system – hot or cold water is circulated via pipes, which are embedded in floors, walls or ceilings, and thus form an integral part of the building. It is often combined with geothermal solutions, using the soil’s heat that is extracted with a heat pump. These systems fulfil two functions at once: in winter they heat the rooms, while in summer they cool them down by running cold water through the pipes. Through their large-area installation, they ensure the distribution of heating or cooling in the room, contributing to a pleasant indoor climate all-year round.14 Apart from the comfort these systems provide, surface heating and cooling is a cost-effective, energy efficient, sustainable solution.

This almost 13-minutes US video explains how geothermal heating and cooling systems work and why they are more sustainable and energy-efficient than the old-fashioned heating and cooling using electricity or natural gas.

In Australia, there are attempts to promote and implement these innovative sustainable heating and cooling technologies, but they are not extremely known by the larger public yet. GeoFlow and Geothermal Heating and Cooling Australia are one of the Australian pioneers.

Air flow

Air attempts to equalise between regions of higher and lower air pressure. If there is a pathway (a gap) and a pressure difference, whether we want it or not, it will pass through that pathway. 

A material must not only obstruct airflow through it; it must also be mounted in a manner that avoids even minor gaps, be continuous all over the conditional space and be robust in order to be an efficient air barrier or air flow retarder. 

If the quantity of air collected from the enclosed space (exhaust systems or air returned to the air conditioner) does not equal the quantity of air supplied to the enclosed space, an imbalance of pressure is produced. 

When more air is removed than added, a negative pressure occurs, causing the building to draw air into it to compensate (air infiltration). 

A balanced air pressure is best in all climates, but hard to maintain. A slight positive pressure is beneficial in warm climates; a slight negative pressure is desirable in cold climates to avoid secret issues with moisture in building cavities. 

• Leaky attic ducts create adverse pressure inside homes and increase air penetration through walls or spaces and floors that crawl. That means sticky, humid infiltration of air in summer. That means cold drafts in winter. 
• A balanced air pressure is best in all climates, but hard to maintain. A minimal negative pressure is preferable in warm climates to avoid secret moisture issues in building cavities. 
• A sufficiently high negative pressure will lead to dangerous back drafting of the combustion appliances' chimneys and flues. 

When more air is provided than is extracted from a room, a positive pressure occurs. 

• With a fresh air intake, a positive pressure can be generated and controlled. 
• A powerful wind (hurricane) that enters a home through a broken window will pressurise the house enough to destroy it. 

 

In various parts of a building, forces may produce simultaneous positive and negative pressures. An instance is closing a door to a room that has air distribution supply registers, but no return grille makes the room positive and the return grille area negative. 

Indoor air usually contains more forms and higher concentrations of contaminants than outdoor air, even in industrialised areas. Several common indoor air pollutants in the home include: 

• pollutants that are biological (mould spores, dust mites, bacteria, viruses, pollen, animal dander)
• pollutants (including carbon monoxide) from combustion, lead in dust (from old paint or lead-tainted soil)
• off-gassing (of building materials, adhesives, paints, finishes, pesticides and certain household cleaning products) volatile organic compounds (VOCs) and occasionally asbestos
• in certain places, radon, a toxic gas from the soil, presents a significant threat

 

Moisture flows 

One of the many gases that make up the air we breathe is water vapour. A small amount of water vapour is good; too much is a concern. 

Relative humidity (RH) is an important concept used to understand moisture problems in a building. Compared with how much it would retain at a given temperature, relative humidity is a measure of how much water vapour is in the air. 100 percent RH means the air cannot carry any more water vapour at its current temperature. The target, for energy efficiency in a home, should be to maintain an indoor RH in the 40 percent to 60 percent range, for comfort and health benefits (including deterring the growth of mould). RH should be below 50 percent for optimum dust mite regulation. 

 
Source: Arundel et.al. (1986)12

More water vapour than cold air will carry warm air. It cannot retain as much water vapour when warm, humid air is cooled (RH rises), so the excess condenses into liquid water. Dew point is the temperature that causes condensation or when the RH is 100 percent. That is why cold surfaces 'sweat’. Dew point is the temperature that causes condensation. The solution to condensation (sweating surfaces) is to reduce the air's relative humidity (which reduces the temperature of the dew point) or to keep the surfaces warmer (above dew point). 

In air conditioning, much of the energy used is to extract moisture from the air. Average household activities add about 3 gallons of water each day to the indoor air (as water vapour). 

In two ways, water vapour can pass through a home's walls, ceilings, and floors (the building envelope): 

Air infiltration	Vapour diffusion
Air transports water vapour through holes or gaps in the constructed structure of a home and may bring moisture. Such infiltration can carry a great deal of moisture. Air-carried moisture through a building envelope is a much more significant and important source of moisture movement than through the second vapour diffusion process.	This happens by material diffusion of water molecules. Moisture appears to shift from a higher to lower temperature region and content of moisture. Unless powered by high vapour pressure, the volume of moisture diffused is generally relatively small, such as rain-saturated brick veneer heated on a hot, humid day by the sun. Materials used to avoid or decrease water vapour diffusion are vapour barriers or vapour retarders. They should not be mistaken for air barriers; some air flow retarders are also vapour diffusion retarders, and some are not. To control diffusion adequately, vapour retarders do not have to be sealed or mounted completely free of holes; 90 percent coverage provides a 90 percent reduction in vapour diffusion, which is usually more than enough (since diffusion is usually a minor source of moisture migration). The vapour permeability of a substance relates to how readily water vapour (not air) can diffuse through it. Materials with a perm score of 0.1 or less are known as vapour barriers and are impermeable. As a vapour retarder, a perm level between 0.1 and 1 is graded. A perm grade of 1 to 10 is known to be a semi-permeable vapour retarder. A ranking higher than 10 is water vapour permeable.

Water vapour permeability classification

Perm Rating	Classifications	Description
< 0.1	Class 1	vapor barrier
> 0.1 and <1	Class 2	semi-impermeable vapor retarder
> 1 and < 10	Class 3	semi-permeable vapor retarder
> 10	Class 4	permeable material

 

Here are a few tips:

• Liquid water is not necessarily downward flowing; it can defy gravity. 
• Wind, the momentum of water flow, and surface tension can guide it through surface gaps that are horizontal and even uphill. 
• Liquid water is often attracted by capillary force through the pores and tiny cracks of porous materials. This force causes materials in every direction, including upward, to absorb or wick water (including wood, concrete, stone, etc.). A non-absorbent material or space that interrupts the flow of water from one material to another is a capillary break. 
• The deeper the level of water (floods), the greater the power it exerts (on walls and foundations).
   

 

A cost-effective way to cut heating and cooling costs, enhance longevity, improve comfort, and build a healthy indoor atmosphere is to reduce the amount of air that escapes in and out of your house. Caulking and weatherstripping are two simple and reliable techniques for air-sealing that deliver rapid investment returns, often for one year or less. Caulk is typically used for cracks and gaps between stationary house components such as around door and window frames, and weatherstripping is used to seal components that shift, such as doors and operable windows. 

Leakage of air 

When outside air enters, air leakage happens, and conditioned air exits your house through cracks and openings uncontrollably. For ventilation, it is unwise to rely on air leakage. There could be too much air coming into the house during cold or windy conditions. Not enough air can reach inside when it is colder and less windy, which can result in poor indoor air quality. Air leakage also leads to moisture issues that can affect the health of occupants and the integrity of the building. An additional advantage is that drafts and cold spots are minimised by covering cracks and gaps, increasing comfort. 

The suggested approach is to eliminate as much air leakage as possible and, where appropriate, to provide controlled ventilation. Before sealing the air, first, you should: 
 

Then you should apply techniques and materials for air sealing, including caulk and weatherstripping. If you are planning a thorough building renovation that will require some construction, study some of the methods used in new building construction for air sealing and consider a building energy audit to find all the ways the building is wasting energy and money. 

Tips for air leak sealing 

• For air tightness, measure your house. 
• Caulk and weatherstrip doors and windows that leak air. 
• Caulk and seal air leaks where plumbing, ducting, or electrical wiring comes over cabinets via walls, floors, ceilings, and soffits. 
• Place foam gaskets on the walls behind the outlet and turn plates. 
• For air leaks and mould, check dirty spots in your insulation. Seal leaks made for this purpose with low-expansion spray foam and add house flashing if necessary. 
• Look for dirty spots on your ceiling paint and carpet and caulk air leaks at inner wall/ceiling joints and wall/floor joists. 
• Cover single-pane windows with or replace storm windows with more powerful low-emissivity double-pane windows. For more detail, see the Windows section. 
• On larger gaps around windows, baseboards, and other places where air can leak out, use foam sealant. 
• To avoid air leakage when not in use, cover your kitchen exhaust fan. 
• To be sure it is not blocked, check your dryer vent. This will save resources and avoid a fire from taking place. 
• Replace the bottoms and thresholds of the doors with those with pliable sealing gaskets. 
• Hold the fireplace flue damper when not in service, securely closed. 

 

Fireplace flues are made of metal, and repeated heating and cooling can warp or crack the metal over time, creating a channel for air loss. Consider an inflatable chimney balloon to seal your flue while not in use. When not in use, inflatable chimney balloons fit under your fireplace flue, are made of sturdy plastic, and can be quickly removed and hundreds of times reused. The balloon will immediately deflate within seconds of encountering heat if you fail to remove the balloon prior to making a fire. By filling a plastic trash bag with fiberglass batt scrap and jamming it into the flue, a relatively competent person can build an inexpensive, reusable, do-it-yourself fireplace flue plug. Tie a sturdy cord with a tag that hangs down in the fireplace so that you have a simple method of plug removal when the flue is blocked. It also serves as a reminder that the flue is currently blocked and that the plug must be removed before use. 

The need for adequate insulation to decrease heat flow through the building envelope is not removed by air sealing alone.

 

The need for mechanical ventilation increases as homes become more airtight. Fresh air with reduced heat loss is carried in by heat recovery systems. 

Types of mechanical ventilation 

Four mechanical ventilation systems are available to choose from: exhaust, supply, balanced and energy recovery. Let us look at each form of mechanical ventilation. Here are the four options. 

1. Exhaust ventilation
2. Supply ventilation
3. Balanced ventilation
4. Energy recovery ventilation

 

Exhaust ventilation

Overview of the system: 

Exhaust ventilation systems operate by depressurising a structure. The machine exhausts air from the house, creating a pressure shift that draws in make-up from the outside through leaks in the shell of the building and deliberate, passive vents. For colder climates, exhaust ventilation is most suitable, as depressurisation can pull moist air into wall cavities in warmer climates, where it can condense and cause moisture damage. Exhaust ventilation systems are relatively easy to install and inexpensive. Usually, a single fan linked to a centrally located, single exhaust point in the house consists of an exhaust ventilation system. A better design is to connect the fan to multiple room ducts, ideally rooms that produce contaminants, such as bathrooms and kitchens.

Adjustable, passive vents may be mounted in other rooms through windows or walls to introduce fresh air rather than relying on leaks in the envelope of the house. However, passive vents which require greater variations in pressure than those caused by the ventilation fan to function properly.

Disadvantages:

One problem with exhaust ventilation systems is that they can draw in contaminants along with fresh air. This may include radon and crawlspace moulds, attic dust, attached garage fumes, and fireplace or fossil-fuel-fired water heater or furnace flue gases. When bath fans, range fans, and clothing dryers (which also depressurise the home as they operate) are run while an exhaust ventilation system is also running, these pollutants are a particular concern.

Compared with energy recovery ventilation systems, exhaust ventilation systems may also lead to higher heating and cooling costs because exhaust systems do not temper or extract moisture from make-up air until it reaches the home. 

Supply ventilation

Overview of the system: 

To pressurise a structure, supply ventilation systems use a fan to force outside air into the building while air escapes out of the building through holes in the shell, bath and range fan ducts, and intentional vents (if any). 

The supply ventilation systems are relatively easy and inexpensive to install, much like exhaust ventilation systems. There is a fan and duct system in a standard supply ventilation system that typically delivers fresh air into one, but preferably many, rooms that most people occupy, such as bedrooms and the living room. In other rooms, this device can include adjustable windows or wall vents. 

Compared to exhaust ventilation systems, supply ventilation systems allow better control of the air which enters the building. Supply ventilation systems, by pressurising the home, reduce outside emissions in the living space and avoid combustion gases from being drawn back from fireplaces and appliances. The ventilation of the supply also makes it possible to filter outside air into the house to remove pollen and dust or dehumidify it to regulate humidity. 

In hot or mixed climates, distribution ventilation systems perform best. These systems can cause moisture issues in cold climates since they pressurise the building. The supply ventilation system allows warm interior air to escape through random holes in the outside wall and ceiling during winter. If the interior air is too humid, the attic or cold outer sections of the exterior wall can condense with moisture, resulting in mould, mildew, and decay.  

Disadvantages:

Supply ventilation systems do not temper or extract moisture from the make-up air until it reaches the building, much like exhaust ventilation systems. They can thus lead to higher heating and cooling costs compared to ventilation systems for energy recovery. 

When air is pumped into the house at discrete places, to prevent cold air drafts in the winter, outside air will need to be combined with indoor air before delivery. Another alternative is an in-line duct heater, but it raises running costs. 

Balanced Ventilation 

Overview of the system: 

When properly built and mounted, balanced ventilation systems neither pressurise nor depressurise a structure. Instead, roughly equivalent amounts of fresh outside air and contaminated inside air are added and depleted. 

There are normally two fans and two duct systems for a balanced ventilation system. It is possible to install fresh air supply and exhaust vents in any room, but a traditional balanced ventilation system is built to supply bedrooms and living rooms with fresh air where occupants spend the most time. It also drains air from rooms where humidity and contaminants are created most frequently, such as kitchens, bathrooms, and laundry rooms. 

Some designs use a single-point exhaust, and balanced systems allow the use of filters to extract dust and pollen from outside air before introducing it into the house since they supply directly outside air.

Disadvantages:

Balanced ventilation systems do not temper or extract moisture from the make-up air until it reaches the building, much as all supply and exhaust systems. Hence, unlike energy recovery ventilation systems, they can lead to higher heating and cooling costs. Outdoor air can need to be mixed with indoor air before delivery, like supply ventilation systems, to prevent cold air drafts in the winter. 

As two-duct and fan systems are required, balanced ventilation systems are typically more costly to install and operate than supply or exhaust systems. 

Energy recovery ventilation

Overview of the system: 

Ventilation devices for energy recovery offer a regulated way of ventilating a building while minimising the loss of energy. By moving heat from the warm inside exhaust air to the new (but cold) outside supply air, they lower the cost of heating ventilated air in the winter. The inside air cools the warmer distribution air in the summer to minimise the cost of cooling. 

There are two kinds of devices for energy recovery: energy recovery ventilators (ERVs) and ventilators for heat recovery (HRVs). A heat exchanger, one or more fans to drive air through the system and controls are all included in both forms. Few small wall or window-mounted versions exist, but most are central ventilation systems for the entire building with their own duct system or shared ductwork. 

The biggest difference is the way the heat exchanger functions between an ERV and an HRV. The heat exchanger transfers a certain quantity of water vapour (latent) along with heat energy (sensitive) with an ERV, while an HRV only transfers heat. 

The temperature of the building air remains steadier since an ERV moves some of the humidity from the exhaust air to the normally less humid incoming winter air. This also makes the central heat exchanger warmer, mitigating freezing issues. 

In the summer, by transferring some of the water vapour in the incoming air to the potentially drier air that leaves the house, an ERV can help regulate humidity in the house. An ERV usually provides greater humidity control than an HRV if you use an air conditioner. 

Most ventilation systems for energy recovery will recover about 70-80 percent of the energy in the exhaust airstream and deliver the energy for conditioning purposes to the incoming air.

Disadvantages

Some ventilation systems for energy recovery will cost more than other ventilation systems to install. Simplicity is usually the secret to cost-effective installation. Many devices share existing ductwork to save on construction costs. Not only are complex systems more costly to install, but they are usually more maintenance-intensive and use more electrical resources.

MVHR

To provide efficient ventilation to maintain excellent indoor air quality in occupied buildings, mechanical ventilation with heat recovery (MVHR) is used. Without the electricity, comfort and noise problems that may occur with open windows, it supplies fresh filtered air into the building and simultaneously extracts humid, stale, or dirty air. Mechanical ventilation can be thought of in a controlled manner as supplying constant fresh air. That is, unlike when you rely on opening windows, you can know precisely how much fresh air you get with mechanical ventilation. These systems are designed for continuous operation while consuming very little (usually less than 40 W) power. 

A handbook has been developed by the Australian Building Codes Board that offers details on possible indoor air pollutants, including sources and appropriate levels. This may include carbon dioxide from occupant respiration, gas cooking and unfluted gas heaters in traditional homes; particulates from cooking, tracking in or from carpet deterioration such as PM10 and PM2.5; and volatile organic compounds (VOCs) from synthetic products such as carpets and laminates, cleaning products or even cosmetics. For good indoor air quality, there are certain widely agreed requirements and MVHR systems are built to meet these. 

Why would you need a device for MVHR? 

Natural ventilation is not always going to be enough to ensure good indoor air quality through open windows and doors, as this depends on variables such as window size and location, occupant behaviour, wind speed and temperature. 

A major aspect to remember is the airtightness of the house. Usually, Australian buildings have been designed to a very low airtightness standard (> 10 air changes per hour-ACH-at 50 Pa), so air leakage has been balanced with ventilation using windows. 

Designed ventilation becomes more important as you increase airtightness (to improve building energy efficiency and decrease moisture build-up in walls and roof space). It is difficult to stipulate an airtightness figure at which MVHR becomes advantageous, due to variables such as local wind speeds and window areas, but a rough rule of thumb is that you should start considering MVHR if you plan to hit airtightness levels below 5 ACH at 50 Pa, and certainly look to include it if you are targeting lower levels, such as the Passive House norm of 0.6 ACH. Once construction has begun, it is very hard to incorporate efficient ducted MVHR systems, so this consideration should be part of the design phase for a new building or expansion. 

Whenever it is comfortable to do so, you should open your home. The truth is that there are parts of the year in most places where it is too hot, too cold, too noisy, too dusty, or too dangerous to keep your windows open for long periods of time. 

In MVHR systems, while heat is moved from one airflow to the other to maintain it, air may flow into and out of the house. This shows the centralised structure in the middle of the device with the heat exchanger. 

What to look for 

It is suggested to search for a device that has been checked for heat recovery quality, noise level and energy consumption to an accepted norm. Passive house certification, Eurovent and the European ErP Directives provide existing MVHR test standards (Regs 1253 and 1254). 

A good MVHR unit would have outstanding insulation and it should have an airtight design for both the unit and the ductwork. The existence of features such as rubber O-rings suggest effort has been made to ensure a durable airtight design. Although the build quality of a unit can be difficult for a prospective buyer to assess, those that meet the test criteria will almost certainly have these characteristics. One place for quality systems to be tested is the Passive House Component Database. 

To help you build the system you need for the building, you will also need to find a supplier, whether it is a single decentralised device for the living area or a completely ducted system for your entire building. Many of Europe's biggest and most reliable suppliers already have Australian distributors, so it is not as hard as it once was to find local suppliers for both the initial installation and ongoing support. 

Usually, centralised systems use uninsulated semi-rigid ducts for internal distribution and must therefore be kept within the thermal envelope of the house. 

Price, assurances, and consistency 

Cost is, like most equipment, approximately a representation of build quality, efficiency, support, and service. 

Expect prices for complete ducted systems to range from $7000 to $12,000 for a 250 m2 construction example. Given this wide variety, ask your supplier what is included in their offering and what could be the cheaper or more costly alternatives. 

Decentralised systems range from $1200 to $2000 per unit, noting in our case that you may need two to four sets of these to have a ducted system with equivalent overall ventilation levels. 

Typical warranties vary between one and two years, which is sadly short. It does not actually reflect the performance of the goods, but rather industry norms. Fans, control boards and bypass actuators have components that may malfunction. There are several high-quality, 10-year-old units happily running in Australia and New Zealand, though.

 

 

Interior barrier 

The most effective interior barrier of a building is the interior wall. Making the wrong options for an interior wall would not only lead to regrets but may also mean extra expenses and durability issues. Of course, the determinants of the effect of the chosen interior design include the durability and appropriateness. The building will separate the interior wall from any other property. So, the correct way to accomplish the space is to learn the types of materials available. The typical raw materials that are reasonably priced to help you transform the strength, feel, and look of your interior will be discussed next. 

What is the material for an interior wall? 

A wall material is a finish added to any wall of a home to achieve objectives, including making the building durable, as indicated by the term. 

Interior wall materials 

It is important to remember that various kinds of interior wall materials are offered on the market. To add to the value of any property, it is therefore easy to find one for use. Here are some, however, that are available: 

• Plywood
• Cinder blocks
• Acoustic tiles
• Glass
• Wood
• Cork
• Steel
• Peg Board

Plywood 

It consists of a bunch of sheets of veneer wood that are glued together, even though it is technically understated. As every sheet is swapped at 90 degrees, plywood is robust. This style increases longevity, and warping can be reduced by using several pieces. Plus, it costs less. So, for crafting shelving and built-ins, this is an excellent option. The high price tags of grains are cut by this function. 

Cinder blocks

One obvious alternative is mostly panelled and poured concrete. However, not only for the floors but also for the walls, cinder blocks will also have an industrialised effect. Furthermore, they make it easy to work on counters and shelving. 

Acoustic tiles

This material is valued mainly because of its ability to remit and absorb sound. However, durability and appropriateness also factor in this material. 

Glass 

This material is known to be one of the most flexible forms. Manufacturers keep on exploring their new material. Today, homeowners use it as a structural part for insulation, cladding, and glazing Thanks to the emergence of technology that often lets it transform, it makes great walls. Consequently, during your acquisition, this content is worth watching out for. 

Wood 

Wood has had a long history as a building material for many years. Also, its unique properties inevitably lead to the efficient harnessing of infinite structures for construction. It is also highly flexible, so it is widely used on walls, furniture, and home decor. Perhaps one of the most valuable benefits comes from the fact that it is a resource that is readily accessible. Not only is this going to make it economically viable, but it is also highly stable. Its weight provides sound insulation against the cold. As it can be rendered into various sizes and shapes to fit every house, it is extremely machinable. Wood is also an ecologically friendly commodity because it is biodegradable. 

Cork

This material is not only for framing or shielding, but the sheets are often applied to walls as a viable attractive surface. The positive thing is that as a pre-made covering, it is a good option.

Steel

Steel has remarkable, tremendous strength that gives buildings a great advantage. Its versatility is another critical aspect. Even when exposed to an external force, it bends readily without cracking. Steel comes in a variety of finishes and gauges, so it is easy to design walls with steel. It has been the ideal material in industrial buildings for a long time, but for many contemporary and modern houses, it has also become a common choice. Compared to other products, the collection of steel’s major benefits makes steel-centric projects look more thrilling and outstanding. 

Peg board 

While it is an obvious choice for structural purposes, it is possible to use pegboards to add an unanticipated touch to the walls. When they are painted with a striking colour to create other partitions, they become better. It is more fun if an oversized peg board is used. 

Why do you need material for the inner wall? 

The need for excellent interior wall materials is difficult to overemphasise. Of course, no owner wants to have a building that is neither durable nor aesthetically pleasing. The interior space is always an important part of a building, so a selection of good inner walls is important. It improves the general state of the property when you find that the right material was used on the inside walls. 
 
There is never a shortage of choices in the field of interior design because there is now easy access to a wide variety of raw materials. There are different technologically advanced materials available today for interior surfaces. Many of the choices are interesting, and there is always an option that suits any person’s needs and preferences. Even building materials that are considered inexpensive and low brow can be made to look great.

Exterior barrier

The most effective exterior barrier of a building is the exterior wall. An external wall usually forms part of a building envelope, separating the inside from the outside of the accommodation. Its responsibilities include: 

• environmental control 
• security 
• confidentiality 
• controlling fire 
• aesthetics 

 

To allow light in and views out, it can include openings allowing access and ventilation and glazing. The external wall can also support the combined weight, imposed and wind loads of the roof and floor construction in load-bearing construction such as masonry and transmit them to the foundations. 

The exterior walls may be non-loadbearing in a framed structure and are thus relieved of any upper floor and roof loads. They are typically self-supporting, however, and are intended to withstand wind loads, prevent fire from spreading and accommodate thermal movements. 

Joints accommodating thermal movements can be needed if long, uninterrupted wall lengths are involved. 
 
Materials 

Exterior walls can be manufactured either individually or in combination with other materials from a wide variety of materials. This may include: 

Masonry (stone, brick, and block, for example)

• concrete 
• timber
• cladding metal 
• panels of glass, metal, or timber 
• cladding 
• terracotta 

 

Construction methods that are used to build exterior walls 

To build external walls, various construction systems may be used, including: 

Loadbearing	Frames	Rainscreen
Stone or reinforced concrete, bricks, and blocks for loadbearing walls. For log cabin building, timber is used.	The outside wall may be located around the structure, within (exposing the structure thereby) or as infill panels located inside the frame depth itself. The exterior wall in these cases is generally referred to as 'cladding' regardless of the plane it is in. Usually, these kinds of exterior wall wrap around the frame of the building are non-loadbearing and serve as aesthetic and climatic parts. They can be made of facing bricks, concrete blocks, timber panels, glass, plastic, and other lightweight materials, bound back to the frame.	A thin façade made of metal, terracotta or another type of panel is mounted to a lightweight frame that is bolted to the structure of the building itself. In appearance, it is unlikely that an observer will assume that this façade is of relatively little thickness. A ventilation gap usually exists between the back of the front panel and the building's face (or inner wall). Rainscreens offer an opportunity to retrofit existing buildings with insulation.

It is important to plan buildings for future climate conditions. Wetter winters and rapid, intense downpours make steering rainwater and meltwater away from homes, paved areas, and roads much more necessary. A milder climate will decrease the quality of building materials and impact the buildings' indoor climate. A larger need for cooling would be introduced by warmer summers. 

In is important to protect buildings against infiltration and flooding because of the risk presented by higher groundwater levels, higher water levels in streams and watercourses, and a greater risk of storm surges along the coastline. 

Buildings

It is possible for buildings to be vulnerable to climate change. In the future, the risk of collapse, worsening health and severe loss of value as a result of further storms, damage to snow or subsidence, invasion of water, degradation of the indoor environment, and decreased building life could increase. Stronger storms in the short term are the biggest obstacles.

In those sections of existing buildings that do not satisfy the safety criteria of the building code, storms will constitute a safety risk. In the longer term, in nursing homes, for instance, more and longer-lasting heat waves could have health-related effects, especially for the elderly and the poor. 

Adapting architecture to climate change 

Adaptation could be directly linked to reducing snow-load and storm damage as well as regulating the indoor environment. However, about improving existing buildings, if owners are not familiar with deficiencies in the supporting elements of their buildings, autonomous adaptation will be constrained. Adaptation can occur only in new buildings if requirements are increased. As for counteracting the effects of heat waves, the installation of air conditioning in existing buildings, along with the demand for more effective indoor climate control buildings, could be anticipated. 

It is the duty of individual building owners to ensure that the relevant regulations are complied with and they are also the ones who are searching for solutions to a suitable indoor environment. There will be no improvements in the laws relating to building safety under severe weather conditions in the short term. The new energy framework regulations in the building code are a step towards encouraging solar screening and heat-deflecting windows to counter heat waves, making indoor climate control simpler. 

 

No steps for building extensions or restoration are recommended for the time being. 

In the future, owners of existing buildings need to be aware of the usual defects in the bearing components, with appropriate guidance about how to fix them. In the same way, guidance on new building strategies can reduce extreme indoor temperatures during heat waves, particularly for vulnerable buildings. Finally, construction technicians need to be aware of recommended future-oriented design parameters, such as maximum snow load and wind speed, temperatures and durations of future heat waves, and the maximum amount of precipitation that a building can withstand. 

Adapting architecture to extreme weather conditions¹⁵.

A home provides its occupants with a refuge from the climate, but as the climate changes, the home may not be able to meet this need. In general, temperatures are increasing, sea levels are rising and extremes in the weather are more likely. If climate change is considered when a home is being designed or altered, it is likely to remain comfortable for longer, possibly for its whole life. In Australia the average life of a brick home is 88 years and a timber home is 58 years; many last much longer than this. Decisions that are made about homes today will therefore continue to have consequences for many decades.

Australia, because of its size, has a range of climates which will vary in their response to climate change. In general there will be:

• higher temperatures
• higher annual rainfall in the north, lower rainfall in the south
• longer periods of drought
• increased number of days of very high, extreme or catastrophic fire danger
• increased risk and intensity of severe weather such as tropical cyclones, floods, hailstorms and droughts.

 

Good design for a changing climate is design that is flexible enough to adapt to prevailing conditions while optimising the occupants’ comfort and the house’s livability.

When considering design or redesign of a home, ask the following questions:

• What are the climate variables that could affect the building?
• Will climate change impacts affect the site and the building?
• What are the likely consequences to the home in the event of extreme weather?

 

Strategies set in place early will reduce future costs; linking actions into build, renovation or repair cycles will also minimise costs.

Building flexibility into the process means that changing climate conditions can be taken into. The design incorporates pathways for adaptation in the future, which can be taken as needed without too much additional expense. Examples of such ‘flexible adaptation pathways’ include:

• ensuring that there is enough space in your land to include extra water storage for changing water availability
• building more substantial footings under a deck so that it can easily take the weight of a roof if in future more shade is needed around the house as temperatures rise

 

Examples of unintended results of adaptation actions and possible solutions
Action	Potential unintended result	Example of solution
Ensuring roofs are designed to cope with high intensity rainfall events	May increase roof complexity, which increases the chance that embers will lodge during bushfires	Ensure roof design is simple and minimises the likelihood that embers will be caught in the roof
Installing and using a large air conditioner to cope with hotter temperatures	Will produce more greenhouse gases because of increased power needs	Incorporate passive design or use alternative power sources
Insulating homes and sealing against airflow to minimise loss of heat for energy efficiency	Could change the capacity of the dwelling to lose heat in summer	Design house to allow increased airflow during the relevant periods
Raising floor levels to avoid flooding	May disturb acid sulphate soils by changing the level of the watertable if solid fill is used	Do not use solid fill in areas that may have acid sulphate soils
	Could reduce accessibility for the less physically able	Consider including ramps or other options

 

Cyclones and extreme wind

Extremely strong winds can place a great strain on buildings; any damage to homes can cause subsequent damage to their contents. To minimise the risks:

use improved fixing systems in the roof structure and the subfloor (increasing the strength in one area may cause another area to fail: consult a professional)

• design buildings to minimise the wind loads
• use impact resistant materials for external cladding
• ensure building materials are largely waterproof and drainage design is effective, particularly for flashing, vents and penetrations.

In an established home, ensure the structural fixing elements have not been compromised by corrosion or previous cyclones

Extreme heat

One of the main expected effects of climate change is increasing temperature and a greater number of extremely hot days.

The need for keeping your home cool during the summer months will be greater, particularly during extreme heat. Power failures, and the consequent discomfort, may be more likely during extreme heat events.

There are many options for improving the thermal properties of homes:

• Use the most energy efficient stoves, fridges, lighting and other equipment to lessen internal heat gains from sources.
• Use reflective glazing, external shading and reflective roofing.
• Capture natural ventilation.
• Install whirlybirds to remove heated air from the roof cavity.
• Use green roof design.
• Increase insulation and add thermal mass.
• Use photovoltaic, solar, biomass and wind-powered cooling technology.
• Build your home with an appropriate orientation to the sun.

Effective building solutions may bring you closer to passive house building principles that results in ultra-low energy buildings that require little energy for space heating and cooling.

Risk of fire

There are several architectural ways to minimise the risk of the home burning and/or maximise the safety of the occupant:

• Install shutters and sprinkler systems in high-risk zones.
• Ensure that the roof minimises the risk that burning embers will be caught.
• Use building materials that are fire resistant.

Shutters can cover large areas.

Heavy rain and flooding

Indications are that hailstorms will increase over the south-east coast of Australia, potentially leading to impact damage and moisture penetration.

Given the significant damage that hailstones can inflict it may be worthwhile preparing homes for the impacts. Options for reducing damage include:

• selecting roof materials that are impact resistant (e.g. metal rather than terracotta)
• designing or installing appropriate window protection.

Capturing the extra rain and using it to irrigate green spaces may also offer advantages, such as reducing heat island effects (built-up areas become hotter than nearby rural areas).

The projected increase in rainfall intensity is likely to result in more flooding events. Flooding can be localised or associated with a river system. Possible impacts include water damage to the home and its contents, the undermining of foundations and the contamination of the home by sewage or mud.

The risk of flooding to homes can be reduced by not building in areas which could flood, i.e. along river floodplains and on low-lying coastal areas. Other options to reduce flooding risk include:

• exceeding minimum floor levels
• constructing multistorey homes and using the lower level for non-living areas
• using water resistant materials (e.g. concrete, fibre cement)
• ensuring that drainage allows water to escape after the flood
• raising vulnerable equipment (e.g. service meters)
• building a limited life dwelling to minimise financial outlay
• building a levee around the house
• designing a garden that will safely redirect water.

Storm weather

Storm surges occur when intense onshore winds push waves harder against the coast, and have the most impact during high tides. Other factors that increase the impact of storms are wind strength and direction and coastal characteristics.

As a result, homes near coastlines and estuaries may thus be more likely to flood and may have to cope with rising watertables. Greater foreshore erosion could also expose more homes to the impacts of storm surges and sea level rise (particularly for sandy coasts). Stormwater systems may be less able drain into the sea and therefore may cause flooding further inland.

Options for accommodating the risk or retreating include:

• elevating the home
• ensuring the parts of the home that may flood can cope (e.g. the foundations)
• building a limited life home to minimise financial outlay
• building a transportable home.