Allotment and House Orientation

Alignment and positioning of your house on an optimally oriented allotment will make a substantial difference to the ongoing costs associated with that house.

Orienting the house to maximise the advantage of the sun's path and the prevailing winds is an important step in maintaining comfort levels and thus minimise the house's ongoing heating and cooling costs.

The house design should see the living areas and associated windows being placed on a northerly aspect to take advantage of winter sun with sun minimised through the use of eaves and shade during the summer months. Windows should be avoided being placed on the south side of he house and the east and west facing walls shaded from the Sun in Summer.

Good orientation even on smaller allotments is still quite achievable with careful passive design.

Achieving good house orientation requires consideration of:

• Prevailing climate in the area;

• Determining True North and the Sun angles for the allotment;

• Optimum building design for your Climate Zone; and

• The effects of Climate change.

Ideally you should choose an allotment with good orientation for the prevailing climate in the area.

Heat Pump Heating and Cooling

House heating and cooling is usually the highest consumer of gas or electricity and thus the ongoing cost within a conventional house.

Whilst Heat Pump Air-conditioners (Reverse-Cycle Aircon) are more expensive to buy, their running costs are significantly than for their old Gas or Electric water units. As fuel prices escalate (e.g Gas) this difference in running cost will become more pronounced.

Many Heat Pump Air-conditioning units feature stand-alone split-system units or are fully ducted throughout the house with some of these larger ducted units now featuring air-conditioning zones where different areas of the house are divided into individually controllable zones.

Air-conditioning Heat Pumps don't necessarily need to be installed during the house build however for fully ducted versions, it is preferable to time and stage installation within the house build process. limitations often exist in relation to the amount of subsidy applicable.

For those houses with installed Solar Rooftop Panel Arrays, the Heat Pump power consumption can be significantly offset through the output of the Solar Array thus reducing your house's operating costs even further.

LED Lighting

LED lighting is option that can be mostly retrofitted at any point (i.e unlike wall insulation or double-glazed windows, LED lighting doesn't need to be installed during the house build). These LED lighting units can be purchased as "bulbs" which plug into existing light sockets or as permanently fixed (recessed into the ceiling) as units.

Many LED Light product offerings are dimable and can be set to output a white light or a "daylight" light.

LED lighting power consumption is significantly less than that of the old incandescent light bulbs.

Heat Pump Hot Water

Water heating is usually the second highest consumer of gas or electricity within a house.

Whilst Hot Water Heat Pumps are usually more expensive to buy, their running costs are significantly less than for their old Gas or Electric water units they are replacing. Moreover, at the time of this compilation, these Heat Pump Units often attract Government subsidies for existing houses.

Thought needs to be given to the proposed siting of the unit for noise reasons and the unit needs a sufficiently constructed concrete plinth to withstand its weight.

As with the LED lighting, Hot Water Heat Pumps don't necessarily need to installed during the house build.

Insulation and Noise Abatement

Insulation is one of the most effective ways to increase energy efficiency within a house. Adding or upgrading insulation to a house will result in it being more comfortable to live in and cost less money to heat and cool.

Insulation in the walls is usually difficult to upgrade once the plaster is mounted so some thought must be given to wall insulation during the planning stage and definitely prior to your house's interior fitout, as to what level of insulation is required.

It should also be remembered that ceiling insulation may not be installed over the under-same-roof garage and invariably, not installed inside internal walls.

Furthermore, if noise within the house is expected to be a problem, consideration ought to be given to installing sound-shield material within the affected internal wall cavities (such as media room walls which are directly adjacent to the sleeping and other areas of the house).

The general rule of thumb is that higher rated insulation will result in better climate comfort with lower ongoing heating and cooling cost. So, its important to consider this during the planning stage of your house's construction!

It is recommended for Australia's Cool Temperate Zone (i.e. Melbourne, Sydney or Adelaide) that any ceiling insulation be rated a minimum R4 to R5 however insulation rated at R5 to R6 will provide a better thermal performance. Note for the colder alpine areas, R6 to R7 is recommended to be installed.

Note these recommended Insulation R ratings exceed the minimum mandated R-values and are especially important if your house is to feature a dark-coloured roof or external walls.

Double-Glazing and Other Items

Double-Glazed Windows and Sliding Doors effectively complement the thermal and noise performance of your house's insulation.

Similar to retro-fitting Wall Insulation, the retro-fitment of existing windows and sliding doors with double-glazed units, is not usually an easy exercise. So the recommendation is for this aspect to be seriously considered during the planning stage of your house construction.

Other important factors to actively consider during the planning process, are:

• Importance of choosing thermally appropriate roof and external wall material colours, and;

• Choosing to include eaves in the roof design of a new house.

Many people don't give these factors, the serious consideration they warrant especially in the context of an Australian climate environment which is expected to get warmer going forward.

Moreover, Australia's metropolitan areas are becoming more building-dense with shrinking allotment sizes and with the current trend of dark-coloured roofing and dark-coloured bricks, the rise of the "heat-island" effect is becoming a definite phenomenon impacting our suburbs.

Roof material colour and external wall material colour are two important factors when considering a house's thermal performance. As a general rule of thumb, the lighter the colour of your roof and walls, the better the thermal performance and of course, the lower ongoing cost to heat and cool the house.

As with insulation and double-glazing considerations, consider installing eaves along with light-coloured roof and external walls. This will contribute substantially to reducing the ongoing cost of house heating and cooling, going forward.