Features of your land, such as slope and soil type, will affect the design and cost of building a house or extension, or installing a swimming pool.
Foundation data
Foundation data is information including a report based on soil tests, which recommends the depth of stumps or type of slab or strip footing required. This is critical to working out the contract price.
By law, your builder (also called a building contractor) must get foundation data before you sign the building contract. They cannot give you an accurate price until they see the foundation data from your block.
It is the builder's responsibility to be satisfied the foundation data is accurate. You should not have to pay extra to deal with problems (such as excavating rock) that the builder should have identified from the foundation data.
The soil report is based on soil samples from your land, so your builder must check the soil report samples against the excavated foundations before pouring the concrete.
How to get foundation data
Building companies usually get the foundation data for you, but you can get it yourself through your architect or designer, or by engaging a geotechnical engineer. This means you can give it to other builders, along with plans and specifications, to get accurate quotes.
Your building contract price should include the cost of removing existing foundations, trees, septic tanks and other structures.
Disputes about foundations
If you have a dispute with your builder about foundations (for instance, if they have hit rock and want to charge you more), contact the Building Information Line on 1300 55 75 59 between 9:00 am and 5:00 pm, Monday to Friday (except public holidays). Calling this number costs the same as a local call. Additional charges may apply if you are calling from overseas, on a mobile or payphone.