GS Renovation builds loft conversions in Holloway, where Victorian terraced streets run down from Highbury Fields towards Upper Street. A good many N7 houses have been split into flats, so the first thing we establish is what you own. Where you hold a whole house, we coordinate the engineer and build the conversion under Islington Council building control.
Whole houses and period conversions in N7
Holloway's Victorian terraces divide into two very different situations. If you own the freehold of the whole house, the roof is yours and a rear or L-shaped dormer over the closet wing is usually achievable. If you own a top floor flat in a period conversion, the roof void almost certainly belongs to the freeholder, and you would need their consent and often that of the other leaseholders before anything can be designed, let alone built.
For whole houses, the L-shaped dormer is the design that earns its keep. It gives a double bedroom across the back of the main roof and a bathroom over the closet wing, rather than one narrow room with sloping walls. Indicative London ranges for 2026 put an L-shaped dormer at roughly £55,000 to £80,000, and a plain rear dormer at roughly £45,000 to £65,000, with an en suite adding £8,000 to £15,000 depending on how far the drainage has to run.
Islington Council, fire safety and the party wall
Islington has a lot of conservation area coverage, and where your Holloway street falls inside one, permitted development rights for the loft are removed and the design goes to Islington Council for a decision. The council tends to look more favourably on rear alterations that are not visible from the street, and on mansards that respect the roofline of the terrace, than on a large box dormer that breaks the run.
A converted Holloway terrace usually becomes a three storey house, and Part B then requires a protected stairwell from the new floor down to a final exit, with fire doors to the rooms opening off it and interlinked alarms throughout. That is a decision to make before the stair is built, not after. Steel bearings cut into the shared party wall are notifiable, and the duty to serve notice on your neighbour is yours as the building owner.
- Rear dormers to win full head height across the new floor
- Mansard conversions where planning will not accept a dormer
- Velux and conservation rooflights fitted and flashed
- L-shaped dormers over a rear closet wing
- Dormer cheeks, flat roof and leadwork detailed to last
Why Holloway Homeowners Choose GS Renovation
Holloway homeowners choose GS Renovation because we are straight about ownership and consents before anyone commits money, then deliver the whole build with one team: engineer coordination, steels, dormer, protected stair, insulation and finish, with Islington Council building control carried to completion. Fully insured and building control compliant, with a dedicated project manager and Companies House no. 14611254 behind the work.
- Paperwork and certificates handed over for when you sell
- Water tank removed and the system converted where it blocks the space
- A written scope and programme agreed before work starts
- Party Wall notices prepared for steels bearing into a shared wall
- Free, no-obligation quotations
- Free follow-up visit after completion if anything needs attention