One of the most expensive mistakes on a home renovation is doing things in the wrong order. Laying engineered timber floors before the plaster has dried, fitting a kitchen before the electrics are tested, or decorating before the plumbing leaks have been found — each of these forces re-work at premium rates. Tradespeople rarely share their schedule with each other; that coordination is the homeowner’s or project manager’s job.
The sequence below is the one used on professionally managed UK domestic renovation projects. It is not arbitrary — every stage depends on the one before it, and the reasoning is explained so you can make sensible judgements when your situation varies from the norm.
Why Sequence Saves Money
Disruption costs multiply when trades re-visit completed work. A plasterer who finishes a room and then has to watch an electrician cut chases through the new plaster — because the cable run was missed — will charge for additional making good at day rates of £200–£350 per day, plus materials. The same applies to:
- A floor fitter who installs boards and then has to lift them to allow a plumber access to a sub-floor waste pipe
- A decorator who prepares and coats walls that subsequently need re-plastering due to ongoing damp
- A kitchen installer who fits units before the structural beam above the kitchen opening has been confirmed adequate
The principle behind all of this is simple: wet trades before dry trades; structural before services; enclosed elements before finished surfaces.
Stage 1: Structural Work and Weatherproofing
Begin with any structural alterations — removing load-bearing walls, installing steel beams (RSJs), underpinning, new foundations for extensions, and new ground-floor slabs. These generate the most disruption, the most dust, and the highest risk of the unexpected. Doing them first means subsequent trades work in a stable, structurally sound building.
In parallel with or immediately after structural work, make the building weathertight:
- Roof repairs or re-roofing
- New or repaired flashings at chimney stacks and parapet walls
- Window and external door replacements (note: bespoke windows have 6–12 week lead times — order before the builder starts)
- External render repairs or new render
- Guttering and downpipes
Why it matters: Any wet-trade work carried out before a watertight envelope is risky. Rainwater ingress after plastering will cause the plaster to fail, mould to develop, and insulation to become saturated. It is better to delay internal work by two weeks than to proceed into a building that still leaks.
Stage 2: First Fix (Services Before Plasterboard)
First fix is the phase where services — electrical cables, plumbing pipework, central heating pipes, drainage runs, and mechanical ventilation ductwork — are run through the structure before walls and ceilings are closed up. Once the walls are boarded and plastered, these elements are inaccessible without destructive investigation.
First-Fix Electrics
The electrician installs all cable runs, back boxes for sockets and switches, and distribution board (consumer unit) positions. In a full rewire of a three-bedroom house, this takes 3–7 working days. All cables must be in the correct positions before boarding, as changing runs after plastering involves chasing (cutting channels in the wall) and making good — adding £50–£150 per chase plus labour.
Building Regulations Part P requires that electrical work in kitchens and bathrooms is either carried out by a registered competent person (NICEIC, NAPIT, or equivalent) who self-certifies, or is notified to and inspected by Building Control.
First-Fix Plumbing and Heating
Plumbers install all pipework below floors and within walls: cold-water mains, hot-water distribution, heating flow and return pipes, and waste runs to soil stacks. This also includes positioning the boiler flue and setting out the cylinder or hot-water unit.
Key decisions to make before first-fix plumbing begins:
- Underfloor heating (wet or electric)? Wet underfloor heating pipework is laid at first fix, before the screed that covers it
- Radiator positions? These should be agreed from drawings — radiators go on external walls below windows in most cases, and the pipe run length directly affects system efficiency
- Bath, shower, basin, and WC positions? Moving these after first fix is expensive; moving them after tiling is very expensive
First-Fix Carpentry
Any structural timber work — new stud walls, new floor joists for extensions, flat-roof decking, loft hatch alterations — goes in at first fix. New studwork provides the structure to which plasterboard is fixed; it must be in place, plumb, and true before boarding begins.
Stage 3: Plastering
Plastering follows once all first-fix services are complete and tested. The sequence within plastering is:
- Plasterboard fixed to studwork and ceilings (12.5mm or 15mm boards depending on the application)
- Board and skim: the plasterer tapes joints, beads external corners, and applies a two-coat skim (bonding coat then finish coat)
- Sand-and-cement render or lime plaster where specified (external walls, wet areas before tiling)
A three-bedroom house typically takes a plasterer or small team 5–14 working days to board and skim.
The drying-out period is the most commonly underestimated stage on any renovation. Fresh gypsum plaster releases approximately 1 litre of water per square metre during curing. A full-house plaster on 150m² of wall and ceiling area releases around 150 litres into the building. Rushing decoration before this moisture has dissipated causes:
- Paint to peel and blister
- Timber skirtings and door frames to absorb moisture and distort
- Adhesive failures in tiles and timber flooring
- Mould growth behind unfixed finishes
Allow a minimum of 4 weeks before painting, and 6 weeks before fixing engineered timber flooring. Running dehumidifiers significantly accelerates drying — commercial units (£40–£100/week to hire) can halve drying time in a well-sealed building.
Stage 4: Second Fix
Second fix is the phase where services are completed and finishes are installed. It is generally done once plastering is complete and sufficiently dry.
Second-Fix Sequence Within the Stage
The most practical sequence for second fix is:
| Order | Task | Why |
|---|---|---|
| 1 | Second-fix carpentry (door linings, skirtings, architrave) | Sets the finished level that tilers and flooring fitters work to |
| 2 | Second-fix plumbing (fitting sanitary ware, radiators, cylinder connections) | Allows pressure testing before decoration |
| 3 | Tiling (kitchen splashbacks, bathrooms) | Fixed to plastered walls; plumbing fittings set positions |
| 4 | Second-fix electrics (sockets, switches, light fittings, consumer unit connections) | Requires decorating to be largely complete around sockets |
| 5 | Kitchen installation | Requires fixed sockets, plumbing connections, and finished flooring levels |
| 6 | Decoration (painting and wallpapering) | After skirtings and architrave are fixed; before or after floor finish depending on type |
| 7 | Floor finishes | Last trade in, as it is the most susceptible to damage from subsequent traffic |
Door hanging deserves specific mention: hang internal doors after decoration, not before. Painting with doors hung requires care around hinges and risks sticking from paint build-up. It is faster and neater to paint the frame and lining complete, then hang the door as a final act.
Stage 5: External Works and Landscaping
External works — paving, decking, fencing, soft landscaping — are almost always last. There are two reasons:
- Heavy material deliveries during the main build will damage any finished external surface
- External drainage connections and service runs to outbuildings are often finalised once the main building layout is confirmed
Do not lay any hard landscaping until you are certain that no further groundworks or services connections will be required. Cutting through newly laid block paving to install an overlooked foul drain costs £800–£2,500 in reinstatement alone.
Common Sequencing Mistakes
Fitting a kitchen before the plastering is dry — moisture causes cabinet carcasses to swell and the kick-board area behind the toe space to develop mould. Allow 6 weeks of drying before kitchen installation.
Flooring before all wet trades — plumbing leaks, snagging, and even changes of mind about layouts all require access that destroys finished floors. Timber flooring is particularly susceptible to swelling from sub-floor moisture.
Decorating before second-fix electrics are complete — sockets and switches frequently leave shadows, patches, and marks on newly painted walls. Finish painting before fitting plates, or accept the need to touch up.
Starting external landscaping before roof drainage is resolved — a blocked or absent downpipe outlet can flood new paving within one storm event. Confirm all external drainage before signing off any hard landscaping.
Plastering external walls from the inside before fixing the damp issue driving from outside — the new plaster will fail. Always fix the source before applying the internal finish.
The sequence above represents professional practice refined over decades of domestic construction. Deviating from it occasionally makes sense — for example, installing a kitchen in a single room that is not being fully stripped, where all services already exist and the risk of moisture or damage is managed. But departing from it wholesale, in the belief that individual trades know best how to sequence their own work without reference to what comes before and after, is reliably expensive.
