1934 mock-Tudor semi — integral garage → bedroom + ensuite + utility (PD route)

Brief

1934 mock-Tudor semi-detached on Pitshanger Lane W5, owner-occupier family of four with elderly parent moving in. Brief: convert the 17m² integral single garage (used only for bicycle and garden storage for 18 years) into a ground-floor bedroom + ensuite + utility room — adding a self-contained ground-floor sleeping suite for the visiting parent. PD route preferred to minimise programme + risk. Existing front-elevation aesthetic (reclaimed Tendring stock to dado + pebbledash render + integral half-timber) must read unchanged.

Challenge

Five issues. (1) Existing garage slab — unreinforced 75mm Victorian-style concrete poured 1934 over compacted London Clay; insufficient for Part L floor U-value (0.18 W/m²K target) without full re-pour. (2) Front-elevation match — Ealing planning officers + Pitshanger Garden Suburb Society both review PD route garage conversions where front infill is involved; the original 1934 reclaimed Tendring stock brick (to dado) + pebbledash render (above) + integral half-timber detail must be replicated indistinguishably. (3) Floor levels — existing garage slab 220mm below internal hallway level (original 1934 stepped detail for water exclusion); new habitable floor must align with hallway threshold to retain accessible single-storey circulation for elderly user. (4) Soil-pipe routing — no existing soil stack to the garage side of the house; new branch routed through side-return void from rear external stack (existing stack serves first-floor bathroom directly above garage) + new vent through roof. (5) Boiler relocation — existing combi boiler mounted on shared garage/hall partition wall; required relocation to new utility room with new flue route through side elevation (Part J + Part L flue clearance check).

Solution

Pre-application engagement Ealing Planning Service week -8 (Ealing 'Lawful Development Certificate' application £150 fee submitted in parallel for resale clarity — issued week +6). Build 7 weeks. Week 1 strip-out + temporary boiler off + slab break-out + excavation 200mm dig for new floor build-up. Weeks 1–2 new reinforced floor slab — 150mm well-compacted Type 1 + 1200g DPM + 100mm PIR (Celotex GA4000) + 75mm reinforced screed (A142 mesh) U-value 0.16 W/m²K + wet UFH loops (Wunda 16mm pipe centres 150mm). Week 2 internal block-and-render wall liner on existing single-skin garage walls — 50mm cavity + 100mm PIR (Celotex GA4000) + service zone + 12.5mm plasterboard skim — U-value 0.21 W/m²K. Weeks 2–3 front-elevation infill — original 1934 garage door + steel lintel removed + new opening blocked up with reclaimed Tendring stock brick to dado (sourced from Lassco Wandsworth — 1930s reclaimed match identified by Ealing CO via 12-brick sample panel) + pebbledash render above to match (M&S Vellings render with original aggregate sample matched 80:20 Thames sand + 6mm Cornish granite chip) + integral half-timber 100×25mm oak band painted Bulmer 'Tudor Black' to match existing. New 1200mm × 1500mm timber-frame casement window inserted centrally — Mumford & Wood double-glazed slim-sightline 28mm to match original 1934 leaded-light proportions (no leaded-light replication — Ealing CO accepted plain glazed where new). Weeks 3–4 first-fix M&E. New soil-pipe branch routed through side-return cavity via existing first-floor stack route — 110mm uPVC + 75mm vent through roof Part H compliant. New combi boiler installation Worcester Bombardier 25kW in utility room + new horizontal flue through side elevation Part J 600mm clearance from any opening. New 6kW electric heat load + 100A consumer-unit upgrade. Weeks 4–5 internal partitions + ensuite tanking. New 100mm timber stud partition wall separating bedroom from ensuite + utility — 2× 15mm plasterboard + Rockwool RWA45 acoustic + Genie clip-on bars Rw 48dB. Ensuite Schlüter-KERDI tanking system + KERDI-DRAIN linear drain + 600×600mm Carrara marble floor + walls + Burlington traditional thermostatic shower + bespoke single-basin oak vanity + Burlington traditional taps. Weeks 5–6 finishes. Bedroom 14m² engineered oak floor 240mm wide-plank over UFH + Farrow & Ball 'Wevet' walls + Original BTC pendant fittings + bespoke wardrobe wall by Naked Doors. Utility room 4.5m² with Belfast sink + integrated Bosch washer + dryer + Belling integrated dishwasher (for the new bedroom kitchenette use case) + Edward Bulmer 'Pale Hone' walls + Carrara marble worktop + reclaimed quarry-tile floor. New side-access utility door (Builderr-fabricated oak frame + cottage-style double-glazed timber door matching the existing rear cottage door). Week 7 commissioning + air-tightness test (achieved 4.8 m³/h/m² @50Pa against Part L 8.0 target) + LDC issued + snagging + handover.

Outcome

Lawful Development Certificate issued week 6 — confirms front-elevation infill, internal conversion + utility door + flue route all fall within Schedule 2 Part 1 Class A + Class B PD rights (no breach of frontage projection, no breach of cubic capacity, no breach of materials test). Project completed Q2 2026, on programme. Elderly parent moved in week 8. The ground-floor self-contained sleeping suite (14m² bedroom + 3.2m² ensuite + 4.5m² utility/kitchenette) functions as fully accessible single-storey accommodation — level-threshold side access door + level-threshold internal hallway connection + thermostatic shower with grab-rail + lever taps throughout. Front elevation reads indistinguishably from neighbours' 1934 originals — Pitshanger Garden Suburb Society confirmed 'no perceptible change' in pre-completion review. Resale agent (Sinton Andrews Ealing) valued the uplift at £105,000 against £48,500 spend = 117% gross ROI — significant uplift driven by the multigenerational-ready ground-floor suite differentiating from peer 1934 semi stock. Builderr first formally-LDC-certified integral garage conversion + first multigenerational ground-floor suite + first front-elevation Tendring stock + pebbledash + half-timber matched infill with CO 12-brick sample panel approval. Ealing 2nd portfolio case study + Pitshanger Lane first.