GS Renovation converts lofts in Angel, where Georgian and Regency townhouses and later Victorian terraces sit inside Islington's conservation areas. In N1 the honest starting point is what your roof height allows and what the council will accept. We coordinate the engineer and the drawings, then build the conversion and see it through building control.
What an N1 townhouse roof will actually give you
The first measurement on any Angel loft is the height from the existing ceiling joists to the underside of the ridge. Below roughly 2.2m you are into lowering the ceilings of the storey beneath or raising the roof, both of which change the budget and the planning position completely. Many N1 townhouses hide a shallow roof behind a parapet, so what looks like a generous attic from the street can be tight once you are standing in it with a tape measure.
Where the roof is shallow, a mansard is usually the only form that produces a genuinely usable storey. It rebuilds the roof as a steep front slope with a near-flat top, gives more volume than any other type, and in this part of Islington it also happens to match what is already on neighbouring roofs. Indicative London ranges for 2026 put a mansard at roughly £70,000 to £100,000 or more, and that is before an en suite at another £8,000 to £15,000.
Conservation areas, listing and Islington Council
Permitted development rights for loft conversions do not survive in Angel's conservation areas, and they never applied to listed buildings at all. That means a planning application to Islington Council in almost every case, and listed building consent on top where the property is listed. Islington also takes a firm line on roof alterations visible from the street, so a rear mansard or dormer set behind the parapet stands a far better chance than anything that changes the front elevation.
We are a contractor, not an architect or engineer, so we work alongside the professionals who produce the drawings and the calculations, and we build to what they specify. On a townhouse that already has two or three storeys, Part B fire safety usually pushes you towards a properly protected stair enclosure from the new floor all the way to a final exit, with fire doors and interlinked alarms throughout. Getting that agreed early avoids reworking a stair you have already built.
- Rear dormers to win full head height across the new floor
- New floor joists independent of the existing ceiling
- En suite plumbing, drainage and mechanical extraction
- Velux and conservation rooflights fitted and flashed
- Water tank removal and conversion to a sealed system
Why Choose GS Renovation in Angel
Angel homeowners come to us because an N1 loft is as much a consents job as a building job. We coordinate the engineer and the planning drawings, build the steelwork and the mansard structure to that design, and carry Islington Council building control through to sign-off. Fully insured, building control compliant, and led by a founder with 30+ years on London roofs.
- Roof made good, leadwork and guttering finished properly
- Interlinked mains alarms fitted and certified
- Site left safe and secure at the end of every day
- Clean, tidy and reliable tradespeople
- A dedicated project manager from first survey to handover
- Registered in England, Companies House no. 14611254