Perth - Class S Soil - 83K Site Costs???!

tuanh8791 · Apr 28, 2023 5:51 pm

Hi everyone,
We are hoping to build our first home in Perth - just a normal single level brick and Colorbond house. The land is a battle axe block in Swan View and the soil is class S and it is on a bit of a slope. The site costs is HUGE and it does not even include any retaining walls or tree removal. We are shocked with Site Costs quote and would appreciate some advice and suggestions please.

The engineer report said we need 600mm sand pad. There is an old sand pad but it is not big enough for our proposed build of 210sqm (including garage).

Is there a way to build on class S Soil without needing a new sand pad?

Below is the breakdown quote for Site Costs from the builder:

35k - Earthworks: sand pad, clean fill, base inspection, base cut and compaction.
10.5k - Earthworks: Subsoil drain and plastic if required.
8.5k - Stormwater to house: Soakwells to meet NCC and engineers requirements
9k - Engineer Footing upgrade
3k - Limestone access track to driveway
2.5k - Boundary Distribution Board/Fuse box
4.5k - Water and Power Run in (30m driveway)
4k - Concrete pump
2k - Temp Fencing
1.2k - Temp Power
1.8k - Planning Fees (if required)
0.9k - NBN Pit and Pipework Design

Thanks so much in advance!

alexp79 · Apr 28, 2023 8:28 pm

Compacted sand pad shouldn't be costing that much?

You would have to go with piles otherwise.

May be 600 mm is overreach, 300 mm should do with stiffened rafted slab in most cases.

tuanh8791 · Apr 28, 2023 9:36 pm

alexp79

Compacted sand pad shouldn't be costing that much?

You would have to go with piles otherwise.

May be 600 mm is overreach, 300 mm should do with stiffened rafted slab in most cases.

I am not sure whether Perth has its own way of doing things in regards to this. Most of Perth has class A (sandy soil), except for some areas near rivers or hills.