Project Type
Single-Storey Rear Extension
Duration
12 weeks
Project Value
£62,000
The Challenge
The 1930s semi had an existing poor-quality conservatory at the rear that required demolition before the new extension could begin. The neighbour to one side had raised concerns about the shadow the extension would cast on their garden in winter, requiring a daylight and sunlight assessment to be submitted with the planning application. There was also a gas main running close to the proposed foundations which required CAT scanning before any excavation.
Our Solution
A BRE daylight and sunlight assessment confirmed the extension would not materially affect the neighbour's garden in any season beyond the existing conservatory's impact. Barnet's planning officers accepted the assessment and approved the application in 8 weeks. The gas main was confirmed at 900mm depth by CAT scan — foundations were adjusted to 1.1m strip foundation with a concrete top slab bridging the main.
Results
- ✓Barnet planning approval in 8 weeks — daylight assessment accepted
- ✓Neighbour concern resolved with BRE assessment
- ✓Gas main CAT scanned — foundations adjusted accordingly
- ✓18m² open-plan kitchen-diner created
- ✓Three-panel bifold doors to garden — 2.7m wide
- ✓Structural rooflight providing natural light throughout
- ✓Estimated property value uplift: £70,000
Key Features
- ✓Barnet planning consent — daylight assessment satisfied
- ✓CAT scan and foundation adjustment over gas main
- ✓Three-panel bifold doors to rear garden
- ✓Structural rooflight over kitchen workspace
- ✓Underfloor heating throughout extension
- ✓Matching render exterior to existing 1930s house
Specification
| Item | Specification |
|---|---|
| Extension walls | Reinforced concrete strip foundation, block and render external walls, cavity insulated |
| Bifold doors | Smart Architectural Aluminium three-panel, 2700mm wide, RAL 7016, double-glazed |
| Rooflight | Velux Modular Skylights, 2×900×900mm, triple-glazed, flush with flat roof |
| Kitchen | Howdens Greenwich Ivory kitchen, Silestone Blanco Norte worktops, Neff appliances |
| UFH | Heatmiser PL-6 wet underfloor system, 65mm screed, single zone thermostat |
| Flat roof | Sarnafil S327 PVC membrane single-ply, mechanically fixed, 20-year contractor guarantee |
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