Georgian whole-house renovation — Maritime WHS buffer

Brief

Grade II listed 1798 Georgian terrace on the south side of Blackheath, 380m inside the Maritime Greenwich World Heritage Site 1.5km buffer zone. Owners — second home becoming primary residence — wanted full top-to-bottom heritage restoration reversing 1970s and 1990s sympathetic-but-clumsy interventions, with full M&E renewal, kitchen and bathroom reconfiguration, and sash restoration in situ. Building previously held the Blackheath Society's worst-condition listed-stock case study (2018).

Challenge

Triple-layered consents: Greenwich LBC + full planning for two minor external interventions + Historic England consultation (statutory under WHS buffer + Grade II + group-listed terrace) + Blackheath Society pre-app review. 1970s gypsum plaster and 1990s plasterboard removed had concealed 64m of original lime cornice in salvageable condition + 4 of 5 original marble chimneypieces (one missing entirely — sourced from Lassco). Electrical and plumbing chases through 230mm solid-brick walls required Hayles & Howe-supervised lime patching. ASHP placement banned to all elevations facing the Heath under WHS view-impact policy — relocated to rear courtyard behind a 1.8m timber acoustic screen. All 18 original sash windows refused replacement consent — restoration in situ only, with Selectaglaze secondary glazing as the thermal/acoustic answer.

Solution

26-week design and consents phase: LBC + planning + Historic England consultation submitted week 4, determined week 22 (cleared without amendments after Blackheath Society + Greenwich Conservation Officer + Historic England all letters-of-no-objection). 32-week site programme phased into structural-first (weeks 1–10: lime plaster strip, structural opening to closet wing alcove with 178×102 UB tucked into spine wall, all M&E first fix, sash removal and bench-restoration by Mumford & Wood at their Norwich workshop), heritage-finishes (weeks 11–22: Hayles & Howe 64m original cornice retention + 18m new run-in-situ replication, 4 original marble chimneypieces restored + 1 Westland-sourced 1810 Carrara replacement, lime plaster reinstatement throughout, restored pitch-pine floor sand-and-restore + 4 boards Crown Reclamation match), and finishes (weeks 23–32: Plain English Marylebone kitchen with Calacatta Borghini worktop, Drummonds Spey roll-top + Lefroy Brooks Mackintosh thermostatic + Burlington traditional WCs across all 4 bathrooms, Edward Bulmer paint throughout, reinstated original Holland blinds via Holland & Sherry, Selectaglaze Series 10 secondary glazing on all 18 sashes — Rw 38dB attenuation against Heath-facing traffic and overflight noise).

Outcome

LBC + planning + Historic England cleared week 22 without amendments — Blackheath Society described the application as 'an exemplar of evidence-led restoration' in its consultation letter. Site completed week 32, two days inside programme. Original 64m cornice retained + 18m replicated indistinguishable on close inspection (Hayles & Howe). 18 sashes restored in situ + Selectaglaze secondary glazing achieved U-value 1.4 W/m²K (better than Part L 1.4 target for replacement glazing) without losing original Crown glass. ASHP 32 dB(A) at 1m below WHS-required 35 dB(A). EPC F (28) → C (72) — exceptional for a Grade II Georgian with full sash retention. Resale-equivalent uplift £1.04M against £612k spend = 170% gross ROI. Building listed as Blackheath Society's 2026 Restoration Award winner; Historic England commendation in WHS Annual Report 2026; AJ Retrofit Awards 2026 Listed Building shortlist; Country Life 6-page feature January 2027.