Excavation · Site Development
The ground every great project stands on.
Terrain prepares the foundation for exceptional homes, commercial developments and landscapes. We don’t simply move earth — we set the tolerance for everything that follows.
Numbers, not slogans.
Operational Record / Updated Q2
- Years In Field
- 18
- Sites Delivered
- 412
- Earth Moved (Tonnes)
- 1,240,800
- Acres Developed
- 4,260
- Drainage Systems Installed
- 1,180
- Retaining Walls Built
- 324
- GPS Grading Tolerance
- ± 10 mm
- Safety Incidents
- 0
Capabilities
The work that decides whether the rest of the project goes well.
A focused scope, executed without shortcuts. Every service is delivered by Terrain crews — no subcontracted earthworks.
- 01
Site Clearance
Selective removal of vegetation, structures and existing site obstacles. Materials sorted for reuse or removed off-site.
- 02
Bulk Excavation
Mass earth movement using GPS-guided machinery. Cut-to-fill modelling minimises haulage and protects the soil profile.
- 03
Foundation & Footings
Excavation to architect and engineer drawings, including dig-outs, piling preparation and footing trenches.
- 04
Drainage & Utilities
Stormwater, sub-soil and utility trenching laser-set to fall. Installed, bedded and signed off before backfill.
- 05
Grading & Final Trim
Laser and 3D machine-controlled grading to surveyor tolerance. The surface a builder actually wants to receive.
- 06
Retaining Structures
Engineered walls in stone, block and timber. Designed with drainage and long-term geological stability in mind.
The Terrain Process
Six stages, transparent at every step.
Site Delivery Lifecycle
- 01
Site Visit
Walk the ground with you. Identify access, geology, drainage and the questions plans never answer.
- 02
Survey & Planning
Topographic survey, soil assessment and cut-to-fill modelling. A plan with numbers, not estimates.
- 03
Earthworks
GPS-guided bulk excavation. Operators with decades on the controls. No surprises in the spoil pile.
- 04
Drainage & Utilities
Stormwater, sub-soil and services bedded to fall. Photographed, recorded and signed off before backfill.
- 05
Final Grade
Laser-trimmed surface to the millimetre. Ready for footings, slabs or landscape build the day we leave.
- 06
Ready for Construction
Site handed over with as-built records, drainage plans and a clean working surface. Quiet, on time.
Selected Project / 001
The Ridge Residence
Hillside terracing, basement excavation and engineered retaining for a private architect-led residence on a 1-in-4 grade in the West Hills, Portland.
- Client
- Halden Architects
- Location
- West Hills, OR
- Earth Moved
- 8,420 tonnes
- Timeframe
- 22 working days
Scope of Works
Selective clearance inside the arborist tree line, bulk excavation for basement and garage, engineered block retaining wall to 3.4m, sub-soil and stormwater drainage, and laser-trimmed final grade to the engineer's slab model.
The Challenge
A 1-in-4 grade with a slip history after heavy rain, an arborist exclusion zone within a metre of the platform edge, and a programme that needed the slab pour to start on day 25 without weather contingency.
Our Approach
We built the lower retaining wall before the upper bulk dig to lock the slope, ran GPS machine control to a 50mm pre-trim and 10mm final-trim tolerance, and CCTV-tested every sub-soil drain run before backfill went anywhere near it.
Outcome
Platform and garage delivered at design level three days early. Retaining wall back-drained to free-draining gravel. The concrete contractor poured the slab with zero adjustment to the prepared surface.
Field Note / Halden Architects
“The finished grade matched the engineer’s model within tolerance. Our concrete contractor made zero adjustments before the slab pour. That has never happened to us on a sloped site.”
A full archive of completed residential, commercial and civils projects — with site data, drawings and outcomes.
View Project Archive →Precision & Technology
Old craft, sharp instruments.
We invested in the technology that closes the gap between the engineer’s drawing and the surface the builder receives. The tolerance is set on the machine, not in the foreman’s notebook.
- T.01
GPS Machine Control
Topcon and Trimble guidance on every dozer and excavator. Operators grade to model, not to memory.
- T.02
Laser Grading
Rotating laser systems for precise final trim across slabs, driveways and landscape sub-grades.
- T.03
Drone Site Surveys
Photogrammetric surveys produce volumetric earthworks data and progress records to the cubic metre.
- T.04
Digital Site Plans
Engineer and architect drawings converted to machine models. The site is the drawing.
Field Note / Halden Architects
“We design buildings that depend on the ground being right. Terrain is the only contractor we’ve worked with whose grade actually matches what was modelled. The slab pour was uneventful — which is the highest compliment we can give a site contractor.”
Begin Here
Every successful project starts with a site visit.
Send us your drawings, a site address, or just a few photos. We’ll walk the ground with you and write back with a clear, itemised scope — usually within five working days.