What actually sets your build budget
Floor area is the number everyone fixates on. It's rarely the one doing the damage.
Area is a poor proxy for cost
Two homes of identical size on two different Adelaide sites can differ enormously in cost. The variables that move the number hardest are the ones you can't see on a floor plan: soil classification, fall across the site, access for machinery, and how far services have to travel.
Site works are the quiet line item
Retaining, excavation, drainage and driveway access on a sloping block can consume a meaningful share of a budget before a single wall is framed. On flat sand in the western suburbs, the same house costs materially less to get out of the ground.
Specification compounds
A single decision — say, moving from standard aluminium windows to thermally broken commercial glazing — doesn't just cost more per unit. It changes the framing, the flashing details and sometimes the structure. The good news is the reverse is also true: one or two well-chosen downgrades can fund something you care about more.
What to do about it
Get a builder to look at your site before the design is finalised. It is the cheapest hour in the entire process and it routinely saves a redesign.
Thinking about a project? A first conversation with us costs nothing and is usually more useful than another evening on Pinterest. Get in touch.
Before you brief an architect.
Twelve decisions that quietly set your budget long before a single trade quotes — and what each one costs you to change later.
- Why site conditions beat floor area, every time
- Where heritage and council overlays actually bite
- The five specification choices that move the number most
- How to read a builder's quote — and what's missing from it