A typical brief
The owners of an Edwardian semi in Twickenham, Richmond upon Thames, want a master bedroom and bathroom in the roof. The hipped roof leaves little usable floor, so a hip-to-gable extension combined with a rear dormer is the only way to make the space work.
Constraints and planning context
In this scenario the house sits in a conservation area covered by an Article 4 direction that removes Class B roof rights, so the whole scheme needs householder planning permission rather than a Lawful Development Certificate. Richmond’s guidance treats hip-to-gable extensions on semi-detached pairs with caution and expects rear dormers to read as subordinate additions, set in from the sides and down from the ridge.
How we would design it
A full-width dormer 300 mm below the ridge is the scheme most owners want, and it is the one Richmond most often refuses in a conservation area, on the single reason that the bulk harms its character. Rather than risk that refusal and a written-representations appeal of 4–6 months, we would design for approval first time: a dormer at about 60 per cent of the roof width, set 500 mm below the ridge and 500 mm in from the new gable, with slate-hung cheeks and a brick gable matching the flank wall. Conservation-style rooflights light the front.
Likely planning route
A householder application decided within the statutory 8 weeks, with conditions on materials the usual outcome for a subordinate dormer. The application fee is £528 (verify before applying). If a scheme has already been refused, we review the reasons and advise between a revised application and an appeal.
Documentation we would prepare
- Measured survey and existing drawings
- Two full sets of proposed plans, elevations and sections
- Heritage statement addressing the conservation area
- Refusal analysis and resubmission strategy
- Householder planning application and officer liaison
Read more about our loft conversions, householder planning applications and appeals and refusals, see how we work in Richmond upon Thames, or get an instant estimate.
