Core budget categories
- Prelims and site setup: protection, skips, scaffolding or tower access, temporary electrics
- Structure and weathertight shell: steels, openings, roofline, insulation and membranes
- First fix: plumbing and heating routes, electrics, data, underfloor heating manifolds
- Second fix: kitchens, bathrooms, doors, ironmongery, sanitaryware, lighting
- Finishes: plaster/lining, flooring, decoration, silicone and snagging
- Fees and compliance: designers, structural engineer, planning/building control, Party Wall surveyors where needed
- Contingency: typically 10–15% on refurbishments; more if opening up unknown voids
Ask whether quotes include VAT and whether long-lead items (glazing, bespoke joinery) are allowance-only — two common reasons estimates diverge.
Where to spend first
Structure, weathertightness and safe electrics underpin everything else. Insulation and ventilation upgrades often pay back in comfort before you spend on feature lighting. In kitchens and bathrooms, spend on carcasses, worktops and waterproofing details; save on handles and splashbacks if you need to phase.
Tracking costs during the build
Agree how variations are priced (labour rate, markup on materials) before work starts. Use stage sign-off for payments — certificate of completion for electrics and gas where applicable — and keep a single shared list of agreed extras.
Weekly or fortnightly budget reviews beat a surprise invoice at the end, especially on whole-house jobs.