Basement Excavation
Going down, usually against a boundary and usually into rock
Bulk and detailed excavation for residential and commercial basements. The deepest and most constrained digs we do: hard against boundaries, often into rock, with a retention system designed by others that the excavation has to work around rather than through.
Carried out under demolition licence AD214737
Before anything starts
Six things have to be settled first, and not all of them are ours
Most jobs that run late run late on this list rather than on the work itself. Each line says who owns it.
- 01
Geotechnical investigation
Who You, through a consultant
Rock level, rock strength and groundwater. Without it the rock is priced on rates rather than a figure, which is honest but less useful to you.
- 02
Retention design
Who You, through your engineer
Shoring, piling, anchors or a battered face. This is designed by others and the dig sequence follows it, not the other way round.
- 03
Dilapidation report on neighbours
Who You, through a consultant
On a basement against a boundary this protects both sides and is worth doing before, not after.
- 04
Service location and protection
Who Max, with a locator
In ground services around the perimeter, found before anything goes down.
- 05
Dewatering approval if needed
Who You, through your consultant
If the dig goes below the water table, dewatering has its own approval and its own discharge requirements.
- 06
Truck access and traffic management
Who Max, with council
A basement generates far more loads than a site cut, and where they stand is often the constraint.
Scope
What the quote does and does not cover
Stated side by side so there is nothing to discover later. Anything in the right hand column can be added, it is simply priced separately.
Included as standard
| Item | What that means |
|---|---|
| Bulk excavation | To the design level, in sequence with the retention system |
| Detailed excavation | Footings, pads, pier holes and lift pits within the basement |
| Rock excavation | Hammer and ripper work where the ground requires it |
| Batter and bench | Where a battered face is the designed retention |
| Spoil cartage | Classified and carted as it is generated |
| Trim to level | Base trimmed to the level nominated |
Quoted separately
| Item | Why it is separate |
|---|---|
| Shoring, piling and anchoring | Designed and installed by others. We excavate around them. |
| Dewatering | A separate scope with its own approval and discharge requirements |
| Rock priced as a fixed figure | Priced on agreed rates where no geotechnical report exists |
| Contaminated soil | Classified before it can be priced |
| Structural works | Capping beams, slabs and walls are builder work |
| Survey and set out | From your surveyor |
The detail
Why a basement is not just a deeper hole
- The retention sets the sequence. Shoring or piling goes in before the dig reaches it, and the excavation follows the design in stages rather than going straight to depth.
- There is nowhere to put the spoil. On a basement the material leaves as it is generated, so the trucks and the machine have to be sequenced together.
- Rock arrives partway down. Which means the method and the machine change mid dig, usually from a bucket to a hammer.
- The neighbours are right there. Vibration, settlement and the condition of the adjoining structure all come into the method before they come into the price.
- Water is a live risk. A basement that reaches groundwater is a different job, with approvals and discharge requirements attached.
- Access shrinks as it deepens. Getting the machine out at the end is planned at the start, not discovered at the finish.
What we need to quote it
- The address
- So we can look at access and what is around it
- Photographs
- One from the street and one of the work itself
- Any reports you hold
- Hazardous materials, structural, survey or levels
- Your dates
- What has to be finished by when, and what is waiting on it
We attend the site before quoting anything substantial.
Rock is the variable, so it is priced as one
Where no geotechnical report exists, the rock is priced by the cubic metre at a rate agreed before we start. The strip, the access and the cartage come from the site visit.
Before you book
What people ask about this one
Do you install the shoring?
What if we hit water?
How do you price the rock?
Can you dig right to the boundary?
How many truck loads is a basement?
Get a quote
Send the levels and the geotechnical report
Levels, the retention design and a geotechnical report if one exists. Those three decide almost everything about a basement price.
- Rock priced on rates agreed before we start
- Sequenced around the retention design
- Cartage on the same contract so the dig is not waiting on trucks
Special demolition offer
Get your free demolition quote
Demolition and removal services from $15,999*. Tell us about your project and we'll help you understand the costs.
*Starting price applies to eligible demolition and removal projects only. Final pricing depends on structure size, materials, site access, location, waste disposal requirements, hazardous materials and any necessary approvals. A final quote will be provided following project assessment.