GS Renovation builds loft conversions in Chiswick, working with the handsome Victorian and Edwardian terraces that fill W4 between Chiswick House and the river. Here the planning position usually matters more than the roof. We establish what Hounslow Council will accept, coordinate the engineer and the drawings, then build the conversion and see it signed off.
Designing a W4 loft the council will accept
Large parts of Chiswick sit in conservation areas, and several streets carry Article 4 directions. Both remove permitted development rights for a loft conversion, so the box dormer that would be waved through elsewhere in West London needs a full planning application here, and a large flat-roofed one on a prominent elevation may not get consent at all. A mansard, properly proportioned and detailed to match the terrace, is often the form that satisfies both the council and your floor area.
Where the roof is deep enough and the appetite for planning risk is low, a rooflight conversion is worth considering. Conservation rooflights sit flush with the slope, keep the roof line unchanged and add no volume, and they can turn an existing attic into a study or a spare room at roughly £30,000 to £45,000 on indicative London ranges for 2026. A mansard, by comparison, runs from around £70,000 to £100,000 or more.
Structure, party wall and Hounslow building control
The mechanics do not change with the postcode. Steel beams span between the party walls to carry a new floor and, where there is one, the dormer or mansard structure above. The engineer sizes them and specifies the padstones they bear on. New floor joists sit clear of the existing ceiling joists, which were never intended to carry anything but plaster. We build to that design; we do not produce the calculations ourselves.
Because Chiswick terraces are joined on one or both sides, cutting into a party wall for those bearings is notifiable under the Party Wall etc. Act 1996, and the duty to serve notice rests with you as the building owner. We prepare the supporting detail and programme the work around the notice period. Hounslow Council building control then inspects the structure, the fire protection to the stair, the stair geometry and the insulation before sign-off.
- L-shaped dormers over a rear closet wing
- Structural steel sized by the engineer and set on padstones
- Head height and ridge survey before design
- New floor joists independent of the existing ceiling
- En suite plumbing, drainage and mechanical extraction
Why Choose GS Renovation in Chiswick
Chiswick homeowners choose GS Renovation because a W4 loft lives or dies on the consents. We tell you early whether your street is constrained, coordinate the architect and engineer rather than pretending to be them, and then build the steelwork, mansard or dormer to that design with Hounslow Council building control carried through to completion. Fully insured, Companies House no. 14611254.
- Roof made good, leadwork and guttering finished properly
- Free, no-obligation quotations
- Water tank removed and the system converted where it blocks the space
- Site left safe and secure at the end of every day
- Photographs kept at each stage for your records
- New floor structure carried on steel, never on the old ceiling joists