Design, planning, structural drawings and construction — all delivered by one accountable team. Single-storey rear, double-storey side, wrap-around and full-width extensions across Cheshire and Greater Manchester.
Most extension horror stories start with a split project — architect here, main contractor there, structural engineer somewhere else, and nobody quite willing to own the clash when it happens on site. Our design & build package fixes that: one named project manager carries the job from the first feasibility sketch through to the building control completion certificate.
The day the scaffold goes up and the day you throw the first dinner party in the new space — same team, same accountability.
Every phase a household extension needs — from the first planning sketch to the final piece of skirting — delivered by one in-house team.
Site measure, sketch concepts and planning-ready CAD drawings — done before a single invoice is raised.
Full householder planning applications including design and access statements, plus PD notifications where eligible.
Steels, pad foundations and wall tie-ins calculated and drawn by our consultant engineer.
Traditional strip, trenchfill or raft foundations to suit the site. Drainage, manholes and soil stacks included.
Matching brick, reclaimed brick, K-Rend, monocouche or contemporary cladding — whatever the design calls for.
Bi-fold, sliding and Crittall-style glazing, plus flat-roof lantern rooflights for big, lit-up interiors.
Warm flat-roof build-ups, pitched tile roofs, lead flashings — all built to latest Part L thermal requirements.
Joinery, electrics, plumbing, plastering, tiling and decorating — the same in-house team that started the project.
A 4.8m full-width rear extension on a 1930s semi. Steel goal-post frame, slim-profile aluminium sliders, a 3.5m flat-roof lantern and bespoke oak staircase detailing tying the new space back into the existing house. 16 weeks on site, on budget and on plan.
View full projectA single accountable team, start to finish. No handoffs, no subcontractor blame-games, no surprises.
We visit your property and discuss your vision, requirements, and budget.
Our team prepares designs and handles planning and building regulations.
You receive a detailed, transparent quote with no hidden costs.
Our trusted team delivers your project to the highest standard, on time and on budget.
Final inspection, snagging, and handover. Your project, fully certified.
What homeowners ask us most at the first site visit.
Many single-storey rear extensions fall under Permitted Development and don't need a full application, but there are strict size, height and boundary limits. We check this at the free site visit, and if a formal application is needed we handle the planning submission, drawings and responses to the case officer.
As a rough guide for Cheshire in 2026: a quality single-storey rear extension typically runs £2,400–£3,200/m², with larger double-storey builds £1,900–£2,600/m². Kitchens, stone flooring, bi-fold or Crittall glazing and high-end finishes push this up. Every quote breaks out materials, labour, prelims and contingency separately.
Most single-storey rear extensions run 12–18 weeks on site. Double-storey and wrap-around builds are typically 18–28 weeks. Planning can add another 8–12 weeks up front, and structural drawings and building control submission another 4–6 weeks.
Yes. We work with two trusted Cheshire architectural practices and a structural engineer — all submissions, drawings and building control sign-offs are managed in-house as part of the build package.
For single-storey rear extensions, usually yes. We seal the existing rear wall until the new structure is watertight, and only do the final break-through when we're ready to finish the floor and ceiling across both spaces. For wrap-around or full-width rear extensions we'll walk through a phased plan at the site visit.
Yes. All extension work comes with a 10-year structural warranty through our FMB membership, plus manufacturer-backed warranties on windows, doors and roofing.
CDB have knowledge and experience they use wisely to achieve great outcomes. They are competent, experienced, knowledgeable, friendly, trustworthy, communicative, considerate, and hardworking.
Book a free, no-obligation site visit. We'll walk the garden, check the drains and boundaries, and give you an honest view on feasibility and budget before any drawings are commissioned.