Building on a sloping block in Wollongong: design, engineering and access

Much of Wollongong and the Illawarra coast is steep. A sloping block can be built on, but it changes the design from the start.

What a sloping block changes

Illawarra builders say sloping blocks usually need split-level design, engineering, retaining and planned access. The slope decides how the house sits on the land, where the floor levels fall, how people and trades reach the site, and how stormwater leaves it.

Start with a land assessment

The first step is a land assessment, before any design is drawn. It looks at the fall of the land, access for machinery and materials, the ground itself and the approval pathway, whether that is exempt development, a complying development certificate or a development application. See how the NSW approval pathways work.

Design, engineering and retaining

• Split-level design: floors step with the land, instead of cutting a large flat platform.
• Engineering: footings, retaining walls and drainage are designed by engineers for the site.
• Retaining: walls hold the cut or fill, and they affect both cost and approvals.
• Access: how trucks, cranes and tradies reach the block is planned, because access can change the price.

Questions to ask a builder about your slope

1. What engineering does the slope need, and who arranges it?
2. How will access be managed during the build?
3. Does the fixed price include retaining, or is it a provisional sum? See fixed-price building contracts in NSW.

A Wollongong home builder who starts with a land assessment can answer these before you commit.

Common questions