GS Renovation converts lofts in Sidcup, on the 1930s semis and detached houses that make up most of DA15. Detached properties here have both a larger permitted development allowance and fewer neighbour complications, which makes them among the more straightforward lofts we build. We coordinate the structural engineer and manage Bexley Council building control from application to certificate.
Detached and semi-detached lofts in DA15
The interwar Sidcup house typically has a hipped roof, a traditionally cut structure of rafters, purlins and struts, and enough ridge height to work with, though we still measure roughly 2.2m to 2.4m from the top of the ceiling joists before committing to a layout. Hip to gable with a rear dormer is the standard scheme, at roughly £55,000 to £80,000 on indicative London ranges for 2026, and an en suite adds roughly £8,000 to £15,000 to that.
On a detached house there is no party wall at all, so the Party Wall etc. Act 1996 usually does not apply unless excavation goes close to a boundary, and the scaffold can stand entirely on your own land. On a semi, the steels carrying the new floor and the dormer bear into the wall you share with one neighbour, which is notifiable. The duty to serve that notice is yours as the building owner, and we prepare what your surveyor needs.
Permitted development and Bexley Council
Detached and semi-detached houses are commonly cited as having a 50 cubic metre volume allowance for loft conversions under permitted development, with the standard conditions: materials to match, obscure glazed and non-opening side windows below 1.7m, no verandas or balconies, and nothing built forward of the existing roof plane. Bexley Council maintains conservation areas where those rights do not apply, so we confirm the designation covering your address before any drawings are prepared.
Building control approval is needed on every conversion without exception. Bexley building control will check the engineer-designed steel beams and their padstone bearings, the new floor joists carried clear of the old ceiling, the protected stair route with fire doors and interlinked alarms under Part B, the stair rise, going and headroom under Part K, and insulation and ventilation. We build to the approved design and book the inspections at the correct stages.
- Building control inspections booked at floor, steel and completion
- Staircase design to Part K, including the landing below
- Dormer cheeks, flat roof and leadwork detailed to last
- Structural steel sized by the engineer and set on padstones
- L-shaped dormers over a rear closet wing
The GS Renovation Difference in Sidcup
Sidcup homeowners choose GS Renovation because a 1930s roof conversion is structural work with a comfortable bedroom on the end of it, and both halves have to be done properly. We coordinate the engineer, install the steel to their design, handle Bexley Council building control and finish the room, the bathroom and the stair. Rated 4.9 from 31 reviews on MyBuilder.
- A written scope and programme agreed before work starts
- Protected stair route and fire doors detailed to Part B
- Ridge height measured before any design work is commissioned
- Staircase set out to Part K within the space you have
- Structural engineer instructed and coordinated on your behalf
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