Do I need a geotechnical report before quoting retaining work?

Yes, most engineers and councils will require a geotech report for sloping sites before retaining wall design is finalised.

Is retaining wall work included in a builder's fixed price contract?

Sometimes it is a provisional sum rather than a fixed price, because the exact excavation volume is not known until the site is dug.

How much of a sloping block's budget typically goes to site works?

It varies by slope and soil, but site works and retaining are consistently one of the largest cost blocks on a steep site compared to a flat block.

Retaining wall and excavation specialists for sloping block builds

Before a split-level home on a steep block gets to framing stage, someone has to cut and retain the site. This is a bundle of civil and structural work that sits between the land purchase and the actual home build: excavation, engineered retaining walls, drainage behind the walls, and sometimes piering or screw piles where the slope is too steep for a standard slab or footing.

This work touches both the site works trade and the home builder, and on a lot of sloping block projects it ends up being the single biggest cost variable. A builder who specialises in split-level homes will usually have an established relationship with an excavation and retaining contractor, or run this in-house, rather than leaving you to source it separately.

Cut and fill calculations for the building pad
Engineered retaining walls (concrete sleeper, block, or reinforced concrete)
Subsurface drainage to stop water pooling behind retaining walls
Access tracks for machinery on steep or narrow blocks

What it costs

Retaining and excavation costs scale with wall height, soil type, and how much machinery access the block allows. A steep block with poor access for excavators will cost more than a gentle slope with a wide driveway, regardless of the house design. Get a geotechnical report early so this cost is quoted properly rather than estimated.

Top 3 by our score

Ranked from our published scoring of public Google reviews for sloping block / split-level specialist.

1. New Home Building Brokers
4.9★ · 155 reviews

91
2. Leneeva Homes
5.0★ · 56 reviews

88
3. Home Group
4.5★ · 654 reviews

86

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FAQ

Do I need a geotechnical report before quoting retaining work?: Yes, most engineers and councils will require a geotech report for sloping sites before retaining wall design is finalised.
Is retaining wall work included in a builder's fixed price contract?: Sometimes it is a provisional sum rather than a fixed price, because the exact excavation volume is not known until the site is dug.
How much of a sloping block's budget typically goes to site works?: It varies by slope and soil, but site works and retaining are consistently one of the largest cost blocks on a steep site compared to a flat block.