We all dream of building our own house one day, but before the dreams start to become bricks and mortar, there are some important principles you should consider.

House Site – Don’t be seduced by the view!

Many of us now dream of living on a hilltop with magnificent views, whether these are ocean views, rural vistas or cityscapes. Most of us like going up hills and finding a nice lookout and enjoying the view. It is easy to see why building a house in these locations is appealing.  However there are some disadvantages that should be considered before you build your dream house on a hilltop!

When European settlers first came to the Australia, their dwellings, villages and towns were typically located in a valley near permanent water. Aside from the obvious benefits of having water close by, the soil in valleys is generally deeper, richer and better for cultivating gardens or raising stock. Who wants the “dream house” if you can’t establish a “dream garden” to go with it? Valleys tend to be less affected by extremes of weather such as the winter winds – although they may be more frost prone! The thing to remember is that these principles stand true even today.

If you must have a view from a hill, that’s ok, but remember these disadvantages that need to be considered if you choose to live on a hill: Bushfire danger is most extreme when the fire is travelling up a slope to the site, making a hilltop a worst-case scenario for a bushfire prone site. Accessing the site in all weather can be complicated when dealing with steep grades. Excavating for construction on hilltops can be complicated when rock is encountered – usually not far from the surface of the ground. Water supply is often tricky on hilltops, and may require a pump. Soils are usually shallower and poorer on hilltops than in valleys. Exposure to the elements is usually most extreme on hilltops where winds are more severe and there is little or no shading from the sun.

Aspect – Face facts!

The aspect of a site refers to the direction in which the views are best, or the way the site “faces”. The aspect of the site should affect how a house is designed (although this is often overlooked) and a different aspect will bring different exposure to weather (sun and wind in particular) as well as being overlooked by neighbours or nearby transport corridors.

One of the main considerations is the summer sun. In summer, once the sun comes past the midday peak, a westerly aspect (a site sloping or “facing” west) will mean the windows, doors, decks and verandahs designed to capture the western view will be exposed to up to 8 hours of hot sun. When temperatures exceed 40°C, poor site aspect and corresponding poor house design will mean a house that requires excessive treatment to keep cool. An easterly aspect will decrease problems with heat slightly, as the heat of the summer sun peaks in the afternoon.  A northerly aspect is relatively easy to deal with from a heat perspective, but you must consider shading north-facing windows and doors – a great excuse for a verandah! Southerly aspects offer perhaps the best opportunity to deal with summer heat, if treated correctly.

When dealing with colder climates, the direction of the prevailing wind may change how a dwelling is designed. It may be necessary to use part of the building or other structures as a wind break to create a liveable outdoor area.

Considering the aspect of your site when designing the house is a fundamental factor that can make an immense difference to how a house feels to live in, costs to live there and the attractiveness of the building itself.

Orientation – Knowing which way is “up”!

North is north, right? Wrong! When building a house, you should be aware of the movements of the sun. In Australia, the sun traces an arc in the northern part of the sky. In summer, depending on how far south the site is located, this arc passes nearly overhead. In winter, however, the arc is located more to the north and lower. Consequently in winter the sun “rises” further west and “sets” further east.

When standing on a site facing north, the winter sun will cast a longer shadow behind you than in summer. If there is a window on this site facing north with no shading, the winter sun will reach further through this window than the summer sun. If you are clever with your building design and shade the window the correct amount, you can have the window shaded in summer, but still allowing the winter sun through.

What does this have to do with north? Magnetic north does not represent the “north” based on the arc of the sun. This is known as “True north”.  True north is orientated approximately 10 degrees west of magnetic north. Depending on the design and layout of a house, aligning the walls to true north can provide many passive solar benefits, from reducing heat inside the house in summer to letting sun in to warm the house in winter.

Design – Bring it all together!

All the care taken in choosing your house site can be undone if the house design does not take the site in to consideration. The climate, aspect, orientation and wishes of the owner must be balanced to create a dwelling which is liveable, practical and beautiful. A good building designer or architect should be able to combine the various factors and deliver a design which is sympathetic to the site and climate, while meeting the requirements of the owner. Don’t be afraid to ask questions of the person designing your house – after all you are paying them put your dreams into reality!

Given the rising price of electricity it is important to remember that clever design can make houses much more liveable. Consider window treatments by eaves or verandahs, think about double glazing. Consider new materials and technology in construction such as Eco-Block or similar. Think about the insulation you will use. It may be well worth considering installing solar panels and alternate lighting. Most important is to do your research and talk to experts.

The Dream Home

Before you walk on to a block of land to buy, think about the location, aspect, orientation and design influences you may be dealing with. Steeply sloping sites will inevitably suit some building designs better than others. Winter winds, summer sun – which will have more of an effect, or do both have to be dealt with? Where is the view, and is this compatible with smart design – do you have a western aspect and view in a hot area – if so, how can you take advantage of the view while maintaining a cool house? Are the soils on the site suitable for a garden? Is there sufficient water supply to establish your dream garden? Do water restrictions apply in summer?

When building a new house, many people simply walk in to a project home showroom, pick out a floor plan and randomly place this house on any block of land. Give your dream home some serious thought, and you will be rewarded with a home that is attractive, liveable and inexpensive to run.

Eric Smith

Registered Surveyor