How to Choose a Block of Land for a Custom Home in Sydney (2026)
Start with zoning and what you’re allowed to build
Before anything else, confirm the land is zoned for what you have in mind. Zoning and your council’s Local Environmental Plan (LEP) govern what can be built, how big, and whether options like a duplex or dual occupancy are even possible. Ask for the Section 10.7 planning certificate — it reveals the zoning, overlays and restrictions that apply. Don’t rely on what a neighbour built; rules change.
Check the slope and soil
A flat, stable block is the cheapest to build on. Slope and reactive or rocky soil are among the biggest hidden cost drivers in a Sydney build:
- Significant slope can add tens of thousands for retaining walls, benching and engineered foundations
- Reactive (clay) or problem soil requires more expensive engineered slabs
- Rock excavation can add substantially to site costs
A sloping block isn’t a dealbreaker — some of the best architectural homes make a feature of it — but you need to know before you buy, and budget for it.
Consider Orientation and Light
Orientation shapes how your finished home feels and performs. North-facing living areas capture winter sun and natural light, improving comfort and energy efficiency (and helping you meet NSW BASIX requirements). A good block lets you position living spaces to the north and service areas to the south. Think about this before you buy, not after.
Confirm access to services
Check that the block has, or can readily connect to, water, sewer, electricity, gas and stormwater. Blocks without existing connections — or with services far from the building envelope — add cost and complexity. For battle-axe and rear blocks, confirm access and how services will reach the site.
Look for overlays and constraints
Some constraints can limit your design or push you onto a slower, costlier approval path:
- Heritage listings or heritage conservation areas
- Flood-prone or bushfire-prone land (which can raise construction requirements)
- Easements running through the block
- Tree preservation and significant vegetation
These don’t always rule a block out, but each affects what you can build and what it costs. For more on how they influence approvals, see our guide on DA vs CDC approvals.
Think about size, frontage and shape
Beyond total area, the frontage (width) and shape of a block determine what fits comfortably and whether options like a duplex are viable. A wide, regular block gives more design freedom than a narrow or irregular one of the same size. If a duplex or dual occupancy is your goal, check the minimum lot size and frontage your council requires before committing.
Factor in the hidden costs
The land price is only part of the picture. Budget for stamp duty, demolition (if there’s an existing home), site works, service connections, soil and survey reports, and council or certifier fees. A block that looks cheaper can end up costing more once these are added. Our guide to the cost of building a home in Sydney breaks these down.
Get expert eyes on a block before you buy
The best way to avoid an expensive mistake is to have a builder assess a block before you commit. At Buildrite Sydney, we help clients evaluate land — slope, access, orientation, constraints and buildability — so you buy with confidence and know what your custom home will realistically cost on that site. If you’re weighing up a block, get in touch before you sign.
Frequently Asked Questions
What should I check before buying land to build in Sydney?
Check the zoning and LEP (via the Section 10.7 certificate), slope and soil, orientation, access to services, any overlays like heritage, flood or bushfire, and the block’s size, frontage and shape. Each affects what you can build and what it will cost.
Does a sloping block cost more to build on?
Usually, yes. Slope can add cost for retaining walls, benching and engineered foundations. It’s not a dealbreaker — sloping blocks can produce stunning homes — but you should know the impact and budget for it before buying.
How do I know if a block is suitable for a duplex?
It depends on the land size, frontage, zoning and your council’s controls. Many Sydney blocks qualify, but the local rules set the minimums. A builder can assess whether a specific block suits a duplex before you buy.
Can Buildrite assess a block of land for me?
Yes. We help clients evaluate a block’s buildability — slope, access, orientation and constraints — and give a realistic view of what building there will cost, so you can buy with confidence.