Which site survey do I need before designing a house?

What does a detail and level survey show?

A detail and level survey, which councils also call a contour and detail survey, is the basis for the site plan and the design drawings that follow. The NSW Department of Planning's guide to the DA process lists a site survey among the usual parts of a development application. It also names a land surveyor in the team you may need.

The City of Sydney's survey requirements show how much a good survey holds. Spot levels and contours are tied to the Australian Height Datum, so floor levels and heights can be checked against the planning controls. The survey also locates every existing structure with its floor and ridge levels, along with trees, visible services, kerbs and easements.

It reaches beyond your block as well. Buildings on neighbouring land within three metres of the boundary are shown with their floor levels and the positions of windows nearest your site. Those details let the architect test privacy, overshadowing and views from the very first sketch.

What is a boundary identification survey?

A boundary identification survey, often just called a boundary survey, establishes where your title boundaries actually sit. Fences and old walls are not always on the title line. A small difference can matter when a house is designed close to its setbacks.

The City of Sydney asks for the detail survey to be based on a boundary survey whenever works come within one metre of a side or rear boundary. The plan must note that a registered surveyor carried out the boundary survey, with the surveyor's name and ID number. It must also show fences, walls and buildings with their offsets from the boundaries. The council wants the deposited plan and a title search under six months old with it.

For a new home it makes sense to commission both surveys together. A detail survey without the boundary work can place the design accurately against the ground while leaving the setbacks uncertain.

Do I need another survey later in the build?

Yes, the boundary work comes back before construction. The City of Sydney notes that new buildings and additions must be set out on site by a registered surveyor before work begins. That set out places the footings on the ground exactly where the approved drawings put them.

The survey also sits beside the ground investigation rather than replacing it. A geotechnical report covers the soil and rock under the site, while the survey covers its surface and boundaries. Steep sites need both early, as our guide to building on a sloping block in Sydney explains.

What does a site survey cost?

Survey fees vary from site to site, so ask two or three registered surveyors to quote the same scope in writing. Ask each one how the size and slope of the block, the trees and structures on it and the amount of boundary work will shape the fieldwork and the price.

Make sure each quote names both surveys, the levels datum and whether neighbouring buildings within three metres are picked up. A cheaper survey that leaves out the boundary or the neighbours' windows can cost more later, when the design has to be redrawn around it.

How we use your survey at SHORE

At SHORE Design + Build we begin with the brief and the block, because orientation, fall, outlook and the planning controls all shape what a site will carry. If you already hold a survey from the purchase, bring it to the first meeting. We will assess whether it holds what the design needs and identify anything that must be added. Our guide for owners who have bought a block covers the other site checks. You can also explore design and build in Sydney with us.