Golders Green grew quickly after the Northern line arrived in 1907, and the housing that followed runs from Edwardian bay-fronted houses through to the 1920s and 1930s semi-detached and detached homes that fill many of its streets. Those interwar houses commonly carry hipped roofs, and the hip is what makes the loft brief here distinctive: every slope that cuts back towards the ridge takes volume with it, so the genuinely usable floor is a narrow spine down the centre with the ceiling closing in on three or four sides. The void can be deep and the ridge high while the room you could actually stand up in remains disappointing. Reading that geometry accurately — ridge height, pitch, how far the hip cuts in, and whether the flank wall could carry a gable at all — is the first thing we do, because it decides whether the conversion delivers a full storey or a study.
Before any drawing is worth making, the roof has to be measured properly. The number that matters is the clear height from the underside of the ridge to the top of the existing ceiling joists, because a new floor build-up rises from below and an insulated ceiling drops from above, and the finished room keeps only what is left between them. Where the interwar roof is generously pitched that helps, but a survey usually turns up the things that actually shape the layout: purlins and struts bearing mid-slope, a chimney breast rising through the void, an old cold-water tank, and ceiling joists sized to hold plaster rather than people. We record all of it and then test whether the head height holds across enough of the footprint to justify the work, rather than reporting a single optimistic figure taken under the ridge. Where it does not, a rooflight scheme or a modest study is the honest answer and we say so early.
Hip-to-gable is the move that unlocks a hipped Golders Green roof, and it is also the most visible one. Rebuilding the hipped slope as a vertical gable carries the ridge out to the flank wall and turns a tapering triangle into full-height space — but on a semi-detached pair the result is read from the street, and where the attached neighbour has not converted, the pair can look lopsided. An assessment of a roof alteration is largely an assessment of how it sits within its group. So we look at whether the new gable can be set slightly down from the ridge, whether tile hanging, render or brick matches the host elevation, and whether a half-hip that retains part of the original slope is a better answer than a full gable. Where the address falls within a conservation area, or on the Suburb fringe, that judgement tightens considerably and a rooflight-only scheme may be the realistic one.
Behind the gable, the rear dormer does most of the work. It is where the usable floor actually comes from, and its proportions decide whether the roof still reads as a roof. A dormer set down from the ridge, held in from the flanks and from the new gable, with cheeks in slate or a dark cladding and windows that pick up the rhythm of the openings below, sits far more quietly than a full-width box pushed hard to every edge — and that difference tells when the rear elevation is seen from a neighbouring garden. On the Edwardian bay-fronted houses with a rear back-addition, an L-shaped dormer that turns down over the addition can add real floor area, but the junction between the two roofs, and the rainwater that has to be collected off it, needs resolving before the shape is committed to a drawing.
A hip is a structural element, not just a shape. It braces the roof at the corner, so removing it means a new gable wall and, usually, a ridge beam take over that job, while steel beams span the house to carry a floor the original ceiling joists were never designed to hold. On the semi-detached and terraced stock those beams generally bear into the party wall, and rebuilding a hip as a gable often means building up on the boundary line itself. Both engage the Party Wall etc. Act 1996 — building on the line of junction, or excavating within three or six metres of a neighbour's structure — and the notices are separate from planning and have to be served in their own right. We identify the notifiable neighbours during design so the party wall process runs alongside the application rather than trailing behind it.
Adding a floor changes the whole house, not only the roof. The new stair has to rise from the storey below at a compliant pitch and land with proper headroom, which normally costs a slice of a bedroom or a landing; where an interwar terrace is narrow there is often only one place it can physically go. Once the top floor sits more than 4.5 metres above ground level the escape standard rises: the stair becomes a protected route enclosed all the way to a final exit, with fire-rated doors — typically FD30 — to the rooms off it and mains-powered, interlinked alarms throughout. Houses already opened up at ground floor cannot always enclose that route, and a sprinkler or mist system, or a compliant alternative escape, is then designed in. Building regulations also govern the new structure, insulation, ventilation and stairs, so the drawings carry all of it together.
