Why I run every site assessment myself
What I look at first on any block.
Builder's perspective · Duplex · Wollongong
What I check on a block before I say a duplex will work
Most duplex disappointments start with a design drawn for a block nobody checked. These are the eight things I look at on site, in the order I look at them, before anyone pays for plans.
Why check the block before the duplex design?
Because the block decides the duplex. Its zone, width, fall and services set the layout, the title and much of the cost before a designer draws a line. I run every site assessment myself for that reason: the person who will price and build the job should be the one who walks the block. I have explained the wider approach in why I run every site assessment myself; this page is the duplex version.
What are the eight checks?
- Zone. Dual occupancies are permitted with consent in the R2 Low Density Residential zone across NSW. Other zones depend on the council's LEP.
- Distance to a nominated town centre. Within 800 metres walking distance of the nominated centres (in Wollongong: Corrimal, Dapto, Fairy Meadow and Warrawong), the state's low and mid-rise standards can apply. The town centres list covers the region.
- Lot size and width. Inside those areas the state minimum is 450 m² and 12 m wide. Outside them the council's controls apply, and Wollongong's are mapped lot by lot.
- Fall. Which way the block falls, and how much, often picks the layout: side-by-side or front-and-back.
- Services. Where the sewer runs, whether stormwater can reach the street by gravity, and where two sets of meters can go.
- Access. Two driveways or one long one, and whether a car can actually get in and out at the gradient.
- Constraints. Trees, easements, bushfire or flood mapping, and anything else on the planning certificate that can rule out the faster approval pathway.
- Title. Whether the owner wants to sell one home later, which decides between Torrens title and strata before the plans are drawn.
What can't a site visit tell you?
A walk around the block tells me what to investigate, not the final answer. A survey, a geotechnical report on a sloping block, and the planning certificate confirm what the visit suggests. Where a check is close to a limit, I say so and recommend the report rather than guessing.
What happens after the checks?
If the block passes, the duplex can be designed for it rather than squeezed onto it, with the builder involved from the first sketch (I explain why in builders and designers). If it fails a check, it is far better to know before paying for design. You can see the duplex homes we design and build around Wollongong, and how the process runs from block check to handover.
Related reading
When should a builder be involved in design?
Why the builder belongs at the first sketch.
Sources
- Dual Occupancy, Minimum land size to build a duplex in Wollongong: the Wollongong lot tests.
- Dual Occupancy, Where the low and mid-rise duplex rules apply: nominated Illawarra town centres and standards.
- NSW Planning, Low and Mid-Rise Housing Policy: summary of key provisions.
General information from a builder, not planning, legal or financial advice. Confirm the controls for your lot with your council or certifier.
Questions
Keiron Moore on duplex block checks
What should I check before building a duplex?
Keiron Moore checks eight things: the zone, distance to a nominated town centre, lot size and width, the fall of the block, services, access, constraints such as trees and hazard mapping, and the title the owner wants.
What is the minimum lot size for a duplex in Wollongong?
Keiron Moore explains that within 800 metres of a nominated town centre the state standard is 450 square metres and 12 metres wide, and elsewhere Wollongong's controls apply lot by lot.
Why does the fall of the block matter for a duplex?
Keiron Moore says the direction and amount of fall often decides whether a side-by-side or front-and-back layout works, and where stormwater can drain.
Can a site visit confirm a duplex will be approved?
No. Keiron Moore says a site visit shows what to investigate, and a survey, geotechnical report where needed and the planning certificate confirm it.