GS Renovation converts lofts across Hornchurch, on the 1930s semis and detached houses that make up most of RM11. Wide plots, hipped roofs and generous ridge heights make this good loft territory, usually hip to gable with a rear dormer. We coordinate the structural engineer and run the job through Havering Council building control.
What an RM11 roof will give you
Hornchurch houses were built with space around them, and that shows in the roofs. A detached house here often has enough ridge height and roof depth for a full-width rear dormer without touching the hip at all, while a semi usually benefits from squaring the hip into a gable first. Either way we are looking for roughly 2.2m to 2.4m from the top of the existing ceiling joists to the underside of the ridge before the design starts.
The reward for that space is layout. Instead of one room jammed under a low ceiling, a Hornchurch loft can take a double bedroom, a walk-in wardrobe and an en suite off a proper landing. Indicative London ranges for 2026 put hip to gable with a rear dormer at roughly £55,000 to £80,000, with an en suite adding around £8,000 to £15,000, and cost tends to follow the size of the dormer and the drainage runs.
Permitted development and sign-off in Hornchurch
Detached and semi-detached houses carry the larger permitted development volume allowance, commonly cited as 50 cubic metres, which is why many RM11 conversions proceed with a lawful development certificate rather than a planning application. The conditions still apply: materials to match, no projection forward of the roof plane facing the highway, no balconies or verandas, and obscure glazed, non-opening side windows below the specified height. Conservation areas and Article 4 directions remove the rights entirely.
We confirm the position for your address with Havering Council rather than relying on what happened down the road. Building regulations then apply in every case, and they are the substantive part: engineer-sized floor joists on steel beams, a protected stair route to a final exit with fire doors and interlinked alarms under Part B, stair rise, going and headroom under Part K, and insulation and ventilation to Part L.
- Building control inspections booked at floor, steel and completion
- Protected stair enclosure and fire doors to Part B
- En suite plumbing, drainage and mechanical extraction
- Dormer cheeks, flat roof and leadwork detailed to last
- Mansard conversions where planning will not accept a dormer
Trusted Loft Conversion in Hornchurch
Hornchurch homeowners use GS Renovation because the structural work is the job, and it is what we do daily. We coordinate the engineer, build the gable, install steels onto padstones, form the new floor, fit a compliant staircase and see Havering Council building control through to a completion certificate. Fully insured, Companies House no. 14611254, and 30+ years of hands-on experience behind our founder.
- Water tank removed and the system converted where it blocks the space
- One point of contact on the phone, not a call centre
- Roof made good, leadwork and guttering finished properly
- Materials priced at options, so you choose the finish
- Structural engineer instructed and coordinated on your behalf
- Honest answer at survey if your roof will not take a conversion