SITE AND LOCATION
Ideally, land should be bought after you have defined your needs and requirements in the Design Brief as agreed with your design team.
Your home design starts with the site constraints, including planning rules and ground conditions, which may dictate foundation design. Before that the fundamental questions are where would you like to live and for how long?
So where to start, you need to ask yourself a few key questions:
1. Where do you want to live? Are you prepared to drive a bit or do you want to be close to town or at least some key amenities, even if it’s just your coffee and bread.
2. What is the maximum you are able to spend on the site? To know this you need to know what your house budget will be and that’s not always quantified at this early stage. Research will be needed to confirm the feasibility of the entire project. You also may need to know what level of mortgage you can access.
3. What are the key things you want from your project and site? Size, the view, orientation to north sun, eco-friendly, proximity to work and key things like schools, favourite shops and restaurants or other key amenities.
4. What things are non-negotiable?
5. Which are you willing to compromise on?
Once you find a property of interest you need to do your homework. Agents and lawyers call this due diligence. You also need to check the planning rules and covenants and possibly subdivision rules to ensure that you are actually permitted to build the type of house you want to.
Good sites are hard to find. While it may be difficult to find the perfect site it is essential to find a site suitable for a healthy home. Many subdivisions are not ideal in design and particularly site orientation. Subdivision developers carve up land for maximum yield and profit with little understanding or no consideration of suitability for a well designed and built healthy home.
Road access and site layouts can often mean the long boundary of rectangular properties is north south orientated resulting in the short northern boundary facing the road where the attached double garage blocks sun access for the home.
Ideally an east west orientated site would mean all day north sun access to the entire length of the home.
With this layout the garage would end up either on the south, west or east allowing for a sunny warm dry healthy home to be more easily designed for the site.
Due Diligence
There are often restrictive rules on minimum size homes in subdivisions etc. Are you permitted to build two storey, if that’s what you want? The local council planning rules need to be researched and things like percentage of site coverage permitted under the council zoning to build on a site and recession planes for sunlight and setbacks from the street and internal boundaries. A consultation with a designer is recommended along with a feasibility study.
Engaging a planner may be the easiest way to determine what the planning rules are. Sometimes the duty planner at your local Council may be able to help.
Some other site constraints to consider during you due diligence are
● Natural hazards like inundation due to flooding or climate change.
● Ground conditions and slope stability, if on a hill site.
● Historic contamination; review your Regional Council’s HAIL register.
Hill sites can seem cheap and often have great views but the cost of retaining structures and access provisions can be prohibitive. If considering building on a hill site make sure you get an indication of what the likely costs will be to form the house platform as it may make a substantial impact on your budget.
Overheating
Correctly sized Eaves, and/or other Shading Devices
Eaves are the part of the roof that overhangs the house.
Following the Leaky Homes crisis, the importance of correctly designed eaves became apparent, although less is known about the role they play in allowing sun to enter the home during winter and provide free heat, while shading the windows in summer, minimising the potential for overheating.
What is the “correct size”? The correct size of eaves for your home will be influenced primarily by location, as this determines the path of the sun throughout the year. In summer, the sun follows a “higher” path, while in winter it follows a “lower” path. More on the sun and how it affects your home can be found in the passive solar section.
In summer, you generally want to avoid sunlight entering the home during the middle of the day, as this radiant energy will get absorbed by the building and contribute to overheating.
During winter, and particularly for southern climates, you want to maximise the amount of sunlight that can enter the home, which means having eaves that allow sunlight entering the home when the sun follows a lower path.
Generally speaking, a good rule of thumb is having eaves that extend to an angle of 60-80 degrees from the bottom of your glazing to the eave, depending on your location. Software such as Sketch Up can use your location to show the sun’s path at different times of the year, and give you an accurate picture of how much sunlight will enter your planned home. Late afternoon sun from a westerly direction can also be a problem, but is difficult to address with eave size.
Shading
The single greatest factor in making your home comfortable during summer is managing the amount of sun entering through glazing. One square metre of area produces up to 1kW of heating, which is the equivalent of a 6 fin oil column heater, so managing unneeded sun in summer is key to reducing overheating. Evening sun from the west can also be an issue, as the sun becomes lower and shines directly through west facing glazing. Effective shading means preventing sunlight from entering the home, particularly during the middle of the day, when the sun is at its fiercest. Shading can be achieved in a number of ways, and is more effective if the sun is prevented from entering the home, than once inside (for example by using external blinds, rather than internal ones.) Solutions to this problem can include deciduous trees, awnings, shutters, blinds, pergolas, other buildings and screens.
Recommended Healthy Home guidelines for Site & Location are set out in the table below:
