The single most expensive mistake in a home renovation is doing things in the wrong order. Tiling a bathroom before the plumber has run the shower waste means ripping up tiles; painting walls before the electrician has chased cables means hacking through fresh plaster. A correct order of works is not about perfectionism — it is about avoiding paying for the same job twice.
The sequence below is the industry-standard approach used by experienced project managers and principal contractors. Not every project needs every phase, but the relative order between phases is almost always correct.
The Core Principle
Work outside in, top to bottom, structure before services before finishes. Every trade that comes later must not disturb the work of a trade that came before it. This single rule explains the entire sequence.
Phase 1: Pre-Start and Planning
Before any tools appear on site:
- Obtain planning permission and Building Regs approval (or confirm permitted development applies).
- Serve Party Wall Notices if required (must be served 2 months before works start for Party Wall agreements).
- Appoint and brief your structural engineer if loadbearing walls, floors, or lintels are affected.
- Set up temporary accommodation if you are vacating the property.
- Arrange a site skip (check council permit requirements for highway skips — typically £40–£80 for a 7-day permit).
- Confirm utilities: locate and mark up gas, water, and electricity routes; arrange isolation if needed.
Phase 2: Strip-Out and Demolition
Everything that needs to come out comes out now — before any new material arrives on site:
- Remove carpets, floor coverings, and loose furniture
- Strip back plaster from walls to be chased, tanked, or rebuilt
- Remove kitchens, bathrooms, and sanitary fittings marked for replacement
- Take down internal walls to be removed (after structural engineer confirmation)
- Remove redundant staircases, built-in joinery, or fitted wardrobes
- Strip out old insulation, heating systems, and electrical boards being replaced
Hire a 6–12 yard skip; separate materials for recycling or salvage. This is the correct point to engage a damp survey if there is any visual evidence of moisture problems — before works conceal or complicate it.
Phase 3: Structural Works
All structural work is completed while the building is still open, before any finishes go in:
- Install new RSJ beams, flitch beams, or acro props as designed
- Rebuild or underpin foundations if required
- Install new or replacement structural floors (concrete slab, or engineered timber cassettes)
- Replace rotten or defective joists; strengthen existing floor structure if needed
- Address any subsidence or movement identified in surveys
Building Control inspection required after structural works are complete (or in stages as specified on the Regs application).
Phase 4: External Envelope
Make the building weathertight before interior works begin:
- New roof covering, replacement tiles, or felt underlay if required
- Repair or replace fascias, soffits, and guttering
- New or repaired external walls (brickwork, cladding, render base coats)
- Window and external door replacements installed in openings
- External insulation (EWI) applied if included in scope
- Damp-proof course treatment or tanking to basement and ground floor walls
Do not start first-fix services until the building is fully weathertight. Moisture ingress damages plasterboard, timber studwork, and ironmongery.
Phase 5: First-Fix Services
Services are run before any wall or ceiling finishes are applied:
| Trade | What happens at first fix |
|---|---|
| Electrician | Cable routes (clipped or buried in chase), back boxes, consumer unit position confirmed |
| Plumber | Pipework runs (central heating, hot and cold water supply, soil and waste) |
| Gas engineer | Gas pipework if relocating boiler or radiators |
| MVHR/ventilation | Duct runs to each room; manifold positions |
| Underfloor heating | Pipe loops laid in screed or on timber sub-base |
Chase all cables and pipes before any insulation or boarding. Building Control will want to see pipework before screed is poured.
Phase 6: Insulation and Airtightness
With services in first-fix position, insulation and airtightness membranes are installed:
- Wall insulation (IWI boards, stud frame with batts)
- Floor insulation under screed or between joists
- Ceiling/roof insulation (loft or room-in-roof)
- Airtightness membrane taped at all junctions (critical for energy performance and SAP/EPC compliance)
- Window reveals and service penetrations sealed
Phase 7: Drylining and Plaster
Boards and plaster go on once all services are chased and insulated:
- Plasterboard to ceilings and walls (or lime plaster on solid walls)
- Dot-and-dab or mechanical fixing, taped and jointed, skim plaster
- Fibrous plaster cornice or ornamental mouldings if reinstating period features
- Allow minimum 4–6 weeks drying time before decorating in a plastered home (varies with heating and ventilation)
Phase 8: Second-Fix Services
Services are completed to finished positions — after walls and ceilings are plastered, before floor finishes:
- Electrician: switches, sockets, light fittings, consumer unit connections
- Plumber: sanitaryware, taps, shower enclosures, radiators, boiler commissioning
- Gas engineer: boiler installation and Gas Safe certificate
- MVHR: terminals, balancing, commissioning
Phase 9: Joinery and Internal Doors
- Staircase and balustrade (if new or replaced)
- Internal door linings and doors hung
- Skirting boards, architraves, window boards
- Built-in wardrobes or kitchen carcasses
Phase 10: Floor Finishes
Floor finishes go on after all services are live and tested, and after all dust-generating joinery is complete:
- Floor screed (if not already poured) must reach below 75% RH (typically 4–8 weeks)
- Tile, stone, or LVT to wet rooms first
- Engineered timber or solid wood flooring
- Carpets last of all — after all painting is complete
Phase 11: Tiling and Wet Room Finishes
- Full bathroom tiling — done after plumbing second fix, before grouting any areas near sanitary fittings
- Shower enclosures, glass screens
- Waterproofing (tanking) must be independently checked if behind tiles — once tiled, it cannot be inspected
Phase 12: Decorating
- First coat (mist coat or primer on new plaster)
- Fill and sand any imperfections
- Final paint coats to walls and ceilings
- Gloss or satinwood to woodwork
- Fit ironmongery (door handles, hinges) after final coat to avoid paint fouling
Phase 13: Snagging, Commissioning, and Sign-Off
- Final Building Control inspection and completion certificate
- Electrical Installation Condition Report (EICR) or Part P certificate from electrician
- Gas Safe commissioning certificate
- Boiler serviced and commissioned
- FENSA or CERTASS certificates for windows (if not covered by Regs application)
- Snagging walkthrough — prepare a written list for the contractor; allow 2 weeks for snags to be remedied before releasing final payment retention (typically 2.5–5%)
Common Mistakes to Avoid
| Mistake | Consequence |
|---|---|
| Flooring before second-fix plumbing | Boards cut around pipes; impossible to replace without lifting floor |
| Plastering before services are chased | Cables and pipes chased through fresh skim |
| Decorating before floor screeds are dry | Moisture migration discolours paint; skirting boards cup |
| Fitting kitchen before ceiling is plastered | Dust and debris on new cabinets; cabinets must be masked |
| Tiling before waterproofing is inspected | Failed tanking undetectable until damage occurs |
Following the sequence above costs nothing extra — it is simply the right order. Deviating from it almost always results in additional cost, delay, or both.
