A 3-bed Victorian terrace in Headingley turned into a 4-bed family home in nine working weeks — rear dormer, master bedroom, en-suite, two Velux windows to the front, and a glass-balustrade staircase that lands cleanly under the original ridge.
A young family of four in a 3-bed mid-terrace Victorian property in LS6, two streets back from the cricket ground. Two children sharing the back box room. The Headingley primary catchment they wanted was non-negotiable, the school year had just started, and the only sensible answer was upwards.
The clients had three quotes. Two specialist loft companies and us. We were not the cheapest by a small margin. We won the work because we were the only firm to put the party wall agreements with both neighbours into our scope at no additional fee, and because we committed to a nine-week programme with liquidated damages above week ten.
From scaffold up to keys-handed-back was sixty-three working days. The family slept in their own beds every night of the build except days twelve through fifteen when the existing landing ceiling came down to form the new staircase opening.
The brief was small in scope, tight on schedule, and clear on priorities:
Budget ceiling was £55,000 inclusive of VAT, Velux windows, sanitaryware and decoration.
Loft conversions look standard from the outside. Mid-terrace ones rarely are.
A mid-terrace conversion needs Section 1, 2 and 6 notices to both adjoining owners under the Party Wall Act 1996. We served both notices on day one of the contract, retained surveyors for both neighbours where requested, and had signed awards in hand before scaffold went up — bringing the legal phase entirely inside our pre-construction window.
Building Regulations require 2.0m clear above any staircase line of nosings. The original Victorian rafter geometry gave us 1.94m at the natural landing position — six centimetres short. We solved it by repositioning the new ridge beam 180mm higher than original drawings indicated, which meant a smaller dormer cheek but legal headroom at the landing.
The 4.8m ridge beam (203 x 133 UB, 25kg/m, 120kg total) had to enter the loft through the front roof opening before the front Velux apertures were trimmed. We craned it onto the scaffold lift and walked it in over four operatives. Done in one morning. Trying to manhandle it up the existing staircase would have been a different conversation.
The en-suite needed soil pipe access without coring through any existing first-floor habitable rooms. We routed the new soil stack down the rear corner of an existing fitted wardrobe in the master bedroom, into the existing rear ground-floor service void, then out at low level. No daylight ceilings disturbed below.
Plastic dust-proof curtains hung at the foot of the new staircase opening throughout. Daily site clean. Bag-and-tag carry-down of demolition spoils via a dedicated route through the rear yard, never the main hallway. Two children, no complaints.
The contract carried a half-term completion date. We pre-ordered the Velux windows, the staircase joinery and the steel beam during the pre-construction phase so nothing was on a lead-time critical path during the build. Day one on site was day one of physical works, not day one of procurement.
A nine-week programme on an occupied mid-terrace only works if the legal, design and procurement phases finish before the scaffold arrives.
Pre-construction did the heavy lifting. The four weeks between contract sign and scaffold-up were used for: party wall surveys and agreements with both neighbours, structural calculations and Building Control submission, full M&E coordination drawings, and procurement of the steel beam, Velux units, staircase joinery and en-suite sanitaryware. Nothing on the critical path during the build itself.
Ridge raised, headroom won. The structural engineer's first scheme used the existing ridge line. It gave 1.94m at the staircase landing — six centimetres below regulation. Rather than asking the clients to live with a non-compliant or relaxation-dependent design, we redesigned the ridge to sit 180mm higher. Smaller dormer cheek, fully compliant headroom, and a stair landing that simply works.
One trade out, the next trade in. The 9-week programme was sequenced so each trade arrived as the previous one finished. No two trades on site simultaneously except plasterer and electrician during second fix — their work doesn't conflict and they trust each other. No standing time, no wasted days.
The dormer roof, prefabricated. The dormer roof structure was prefabricated off-site to engineer's drawings and craned onto the scaffold in a single piece. Site-cut timber roof framing on a tight programme is a recipe for slippage. Prefab took three site-days off the schedule.
Sixty-three working days, scaffold to handover.
Independent scaffold erected to rear and front elevations. Existing felt and slates carefully stripped over the conversion zone, salvageable slates set aside for re-use on the front pitch. Loft space cleared, existing ceiling joists exposed.
Padstones formed in both party walls. Ridge beam (203 x 133 UB) craned onto scaffold and walked into position by four operatives. New 47x220 C24 floor joists installed with engineered hangers. New floor decked out.
Prefabricated dormer roof structure craned into position and bolted to ridge beam. Dormer cheeks framed, breathable membrane fitted. Two Velux GGL roof windows installed to the front pitch. EPDM to dormer flat roof, lead flashings to dormer junctions.
140mm PIR between rafters, 50mm PIR overboard to break the cold bridge. Vapour control layer fitted. First-fix electrical: 18 LED downlights, smoke and heat alarms wired to existing CU, USB sockets, en-suite extract fan. First-fix plumbing for the en-suite, soil pipe routed via existing wardrobe void.
Fire-rated plasterboard installed throughout (30 minutes to existing first-floor ceiling, fire integrity to escape route maintained). Existing landing ceiling carefully cut down to form the new staircase opening. Three-day window during which dust-proof sheeting separated upstairs from the rest of the house.
Skim plaster to all walls and ceilings. Bespoke oak staircase delivered and installed: oak treads, painted strings, slim 12mm toughened glass balustrade with stainless top rail. Building Control structural inspection passed.
Second-fix electrical: switch plates, sockets, light fittings. Second-fix plumbing and sanitaryware: walk-in shower tray, glass screen, wall-hung WC with concealed cistern, vanity unit. Full-height porcelain tile to en-suite walls and floor.
Skirting, architraves, internal door fitted and ironmongery installed. Built-in wardrobes constructed against the dormer wall. Two coats of mist plus two coats of finish paint throughout. Carpet underlay and fitted carpet installed across bedroom and landing.
Building Control completion inspection passed. FENSA certificate lodged for the Velux installations. Scaffold struck. Final clean and snagging walk-through with the family. Keys returned, project file delivered with as-built drawings and structural calculations.
The technical detail behind a fully-compliant habitable loft.
4.8m ridge beam (203 x 133 UB) on padstones formed in both party walls. Floor joists 47 x 220 C24 timber on engineered hangers, 400mm centres.
Prefabricated timber-framed dormer with 18mm WBP plywood deck, EPDM weatherproof membrane, fibre-cement cladding to cheeks, lead flashings to all junctions.
2 x Velux GGL MK06 centre-pivot roof windows with white-painted finish, integrated blinds, EDW slate flashing kits matched to existing slate.
140mm Celotex PIR between rafters, 50mm Celotex PIR overboard to eliminate cold bridge, vapour control layer to warm side. Roof U-value 0.15 W/m²K.
Bespoke painted strings with American white oak treads, 12mm toughened glass balustrade with continuous stainless top rail. Compliant with Part K head-height throughout.
30-minute fire-rated plasterboard to existing first-floor ceiling, mains-wired interlinked smoke alarms (landing, hallway, kitchen) and heat alarm (kitchen) per BS5839-6. Fire-rated escape door to new bedroom.
900 x 1200 walk-in shower with low-profile tray, 8mm glass screen, wall-hung WC with concealed cistern, soft-close vanity unit, full-height porcelain tile, ceiling-mounted MVHR extract.
New circuit added to existing CU. 18 LED downlights, 8 sockets (2 with USB), 1 dual-fuel TV outlet, en-suite extract fan with humidity sensor, mains-wired smoke and heat alarms.
A 22m² master bedroom with en-suite, full Building Control sign-off as habitable space, and a staircase that lands cleanly under the new ridge with the regulation 2.0m clear above the line of nosings. The older child moved into the original master bedroom on the Sunday of half-term, four working days inside the contracted programme.
Final account settled at £52,800 against the contract sum of £52,800. No variations. The Headingley local agent assessed the property at a 14–16% uplift versus the un-converted 3-bed comparable down the street.
We had two specialist loft companies quote slightly cheaper. Building Group included the party wall agreements with both neighbours in their fixed price, and they put liquidated damages on the programme themselves — we didn't ask for it. The team were quiet, tidy, and the kids barely noticed they were there. Our oldest moved into her new room on the Sunday of half-term and the youngest got the back box room turned into a proper bedroom. Could not have asked for more.
If you've got a loft sitting unused above your head and you'd rather add a bedroom than move postcode, we'll come out for a free site survey, talk you through party wall, head-height and Building Control, and put a fixed-price quote on the table.
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