Which loft conversion suits a Fulham Victorian terrace?
A rear dormer is the standard and usually the best choice for a Fulham terrace — it creates full-height space across the back slope, typically fits within permitted development, and costs £55,000 to £85,000. Where headroom is marginal or the house is in a conservation area, a mansard may be the only option.
Fulham's Victorian terraces mostly have a traditional cut roof with a reasonable ridge height and a rear slope facing away from the street, which is close to ideal for a rear dormer. The dormer builds a flat-roofed box out from that rear slope, converting sloping roof space into full-height room. Because it is at the back, it is usually invisible from the street, which is what makes it acceptable in planning terms.
A mansard rebuilds the rear roof at a near-vertical angle and gains substantially more floor area than a dormer — often enough for two bedrooms rather than one. It costs more, at £80,000 to £110,000, and almost always requires full planning permission. On terraces where the ridge height is marginal, a mansard is sometimes the only way a conversion works at all.
Hip-to-gable only applies to end-of-terrace and semi-detached houses, where the roof slopes on a side elevation as well as front and back. Squaring that hip off into a vertical gable creates significant volume, and it is normally combined with a rear dormer. On a mid-terrace Fulham house there is no hip to convert, so the choice is genuinely between dormer and mansard.
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