Survey checklist before any work begins
Six surveys before quoting a Victorian terrace renovation. (1) RICS Building Survey (Level 3) £900–£2,400 — comprehensive condition assessment including subsidence, damp, roof, structural movement; essential. (2) Damp survey from independent specialist (not a chemical retailer) £350–£650 — diagnoses rising damp, penetrating damp, condensation; retailer surveys are biased and often misdiagnose condensation as rising damp. (3) Electrical Installation Condition Report (EICR) £180–£450 — Victorian terraces frequently have post-war rewires (1950s rubber insulation, 1960s PVC) at end-of-life; budget full rewire £6,500–£14,500. (4) Gas Safe boiler and gas-installation safety report £80–£180. (5) Drainage CCTV survey £350–£650 — Victorian terraces have salt-glazed clay drainage; cracks, root ingress, and Thames Water build-over agreement issues are common. (6) Asbestos survey £350–£900 — Artex ceilings, vinyl tile adhesives, AIB ceilings can contain asbestos; survey before any disruptive work. Combined survey package £2,500–£5,500.
Damp and ventilation — the weakest point
Victorian terraces have rising damp risk from defective DPC, penetrating damp from rear wall mortar failure, and condensation from inadequate ventilation. Diagnosis by independent damp surveyor; chemical injection is rarely the right answer (Victorian properties typically lack DPC entirely — injection into a 150-year-old wall is not a permanent fix). Rising damp from absent DPC: install a physical DPM at external ground level (re-grade external paving, install French drain to lower ground below internal floor level); or chemical injection (5–10 year typical lifespan); or accept that the lower 600mm of plaster will need annual maintenance. Penetrating damp: mortar joints need repointing in lime mortar (not cement) £85–£140/m²; failed roof flashings around chimney stack — relead £350–£900 per stack. Condensation: install mechanical extract ventilation in kitchen and bathrooms (Approved Document F minimum 15 l/s kitchen, 6 l/s bathroom); add background trickle ventilation in bedroom windows; reduce excess humidity. Most 'damp' in Victorian terraces is condensation — better ventilation is the cheapest fix.
Structural and lintel checks
Victorian terrace structural risks. (1) Lintel failure — original timber lintels above windows and doors deteriorate, especially over rear extensions and side-passage windows; replacement steel or concrete lintel £600–£1,800 per opening. (2) Bay window underpinning — large Victorian bay windows often settle ahead of the main wall, creating a vertical crack between bay and main wall; CCTV survey of bay foundation, possible underpinning £8,500–£18,500 per bay. (3) Party wall cracks — vertical settlement cracks along party walls are common and usually historic; significant new cracks indicate active movement and require structural engineer assessment. (4) Cellar and lower ground floor drainage — original Victorian cellars have minimal drainage; modern conversion to lower-ground habitable space requires Type C cavity drainage waterproofing system £180–£320/m² floor area. (5) Roof structure — original timber rafters 100×50mm at 400mm centres typical; modern loft conversions to L-shape or hip-to-gable require new structural timber/steel beams. Survey by structural engineer £450–£1,200 essential before any structural alterations.
Services, period features and sequencing
Services upgrades on a typical Victorian terrace renovation. Electrics: full rewire £6,500–£14,500 (4-bedroom terrace, 70+ circuits, consumer unit replacement). Plumbing: full re-pipe in copper or PEX £4,500–£9,500; combi boiler replacement £2,500–£4,500; system boiler with cylinder for larger family £4,500–£7,500. Heating: new radiators £180–£450 per radiator × 10–14 radiators = £2,500–£6,500. Drainage: connection upgrade and any required Thames Water build-over agreement £350–£1,500. Period features to retain (resale value): original sash windows — restore or replicate, not replace with uPVC; original cornicing — restore or replicate £150–£350 per linear metre; original fireplaces and surrounds — restore £450–£1,800 per fireplace; original floorboards — sand, re-stain and re-lacquer £35–£65/m². Renovation sequencing: weeks 1–3 strip out and survey; weeks 4–6 structural alterations; weeks 7–10 first-fix services; weeks 11–14 plastering and second-fix; weeks 15–18 fit-out and joinery; weeks 19–22 decoration and snag. Total programme 20–28 weeks. Total cost £120,000–£350,000.
