Single Storey Rear Extension in Bracknell — 1970s Semi to Open-Plan Living

The Brief

A classic Bracknell new-town semi-detached from the early 1970s — three bedrooms, a small rear kitchen, and a separate dining room that nobody used. The clients wanted to remove the dining room wall, push the kitchen back into the garden by 4 metres, and create a single open-plan family space where the children could play while dinner was being made. Budget was important — the brief was quality but not luxury specification.

Our Approach

The 4m rear projection on a semi-detached house exceeded the standard 3m permitted development limit for semis, so it was carried out under the Neighbour Consultation Scheme, which extends this to 6m — no full planning application was required, just the pre-application notification and consultation period. Bracknell Forest Building Control were notified, drawings produced, and a structural engineer calculated the RSJ specification for the wall removal. The existing rear wall was found to be loadbearing during inspection — propping design was confirmed before any cuts were made, and the completed structural work was inspected and signed off with a Building Regulations Completion Certificate.

The Build

Strip foundations at 900mm depth into firm sub-soil. Cavity brick and block superstructure — Ibstock facing brick to outer leaf, 100mm medium-density block to inner. Full-fill Knauf Dritherm 37 cavity insulation. Flat roof framed in 175mm C24 joists at 400mm centres, 150mm PIR insulation (Recticel Eurothane), GRP single-ply deck in grey. Two Velux GGL CK04 double-glazed rooflights installed centrally above the extension. The loadbearing wall between dining room and original kitchen was removed under temporary Acrow props — a 150x75 UC section RSJ dropped in on galvanised padstones. First-fix electrics run to kitchen position, two double sockets each side, LED downlighter circuits.

Materials & Specification

Facing brick: Ibstock Anglian Mixture. Inner block: Thermalite Turbo 7N. Cavity insulation: Knauf Dritherm 37. Roof insulation: Recticel Eurothane GP 150mm. Membrane: laid-up GRP fibreglass system. Rooflights: Velux GGL CK04 double-glazed. Steel: 150x75 UC section.

The Result

The extension added 18 square metres on the ground floor, the dining room wall came down, and the combined space became a 34 square metre open-plan kitchen/dining/family room. Two Velux rooflights bring natural light into the centre of the plan. The project finished on programme and within the agreed fixed price.

Project Photos

Foundation stage — single storey rear extension Bracknell

Flat GRP roof structure and Velux rooflights installed — Bracknell extension

Completed open-plan kitchen/family room extension — Bracknell RG12

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