Structural work
House Extensions
An extension is the single largest change most people make to a house, and the one where the quality of the build is hardest to see once the plaster is on. We work the other way round: the parts you will never look at again — the footings, the steel, the damp-proofing, the insulation line — are the parts we take longest over.
We handle rear extensions, side returns, wrap-arounds and double-storey work on Victorian and Edwardian terraces, 1930s semis and post-war housing across South London. Because the same four people carry the job from excavation to final coat, nothing is handed between trades who have never spoken to each other.
What this includes
- Site set-out, excavation and disposal
- Concrete footings to building-control depth
- Brick and blockwork, cavity insulation and damp-proof course
- Steel beams and padstones to structural engineer’s specification
- Flat or pitched roof structure, insulation, and single-ply or felt covering
- Rainwater goods, flashings and weather sealing
Structure first
Foundations, steelwork and openings are set out against your engineer’s calculations and signed off by building control at every stage before anything is covered up.
One team throughout
Groundworks, brickwork, carpentry and finishing are carried out by the same four people. No sub-contract chains, no gaps in the programme.
A house you can live in
Where the layout allows we keep the existing kitchen usable and seal the works behind dust screens, so you are not moving out for three months.
Scope of works
What a full job covers.
- Site set-out, excavation and disposal
- Concrete footings to building-control depth
- Brick and blockwork, cavity insulation and damp-proof course
- Steel beams and padstones to structural engineer’s specification
- Flat or pitched roof structure, insulation, and single-ply or felt covering
- Rainwater goods, flashings and weather sealing
- Bi-fold, sliding or French door openings and lintels
- First-fix and second-fix electrics and plumbing
- Plasterboard, skim, screed or joisted floor build-up
- Decoration, skirting, architrave and making good throughout
Programme
How the job runs, stage by stage.
- 01
Survey and quotation
1–2 weeks
Site visit, measured check against your drawings, and a written quotation broken into stages so you can see exactly what each part costs.
- 02
Groundworks and structure
3–5 weeks
Excavation, footings, oversite, damp-proofing, brickwork to plate height and steel installation.
- 03
Weathertight shell
2–3 weeks
Roof structure, covering, windows and doors installed. The building is closed in and dry.
- 04
First fix and finishes
3–6 weeks
Services, insulation, plasterboard and skim, flooring, joinery, decoration and final building-control sign-off.
What drives the price
Why two similar jobs quote differently.
We do not publish fixed prices, because a number without a survey behind it is a guess that somebody has to pay for later. What we can tell you is exactly which variables move the figure.
Bring these to the survey and the quotation will be far more accurate.
- 01Footing depth — nearby trees, made ground or shallow drainage can add a metre or more of excavation
- 02Whether drains need diverting or a build-over agreement is required
- 03Span of the opening into the existing house, which sets the size and cost of the steel
- 04Glazing specification — standard French doors against a wide aluminium bi-fold or slim-frame slider
- 05Roof type: flat single-ply, pitched and tiled, or a lantern or roof-light run
- 06Level of finish through the new space, particularly kitchens, flooring and joinery
Do I need planning permission for a rear extension?
Who arranges the structural engineer and building control?
What about the party wall with my neighbour?
How much disruption should I expect?
Often combined with