Sequencing a Whole-House London Renovation: Trades, Programme, and Critical Path

A whole-house London renovation is an exercise in sequencing. Every trade depends on preceding trades having completed their work to a sufficient standard; every trade creates conditions that subsequent trades must work within. Getting the sequence wrong — plastering before first-fix MEP is complete, laying floors before the building is weathertight, decorating before snagging joinery — adds cost, time, and defects. Getting it right allows each trade to work cleanly and completely, without revisiting or making good after others.

This guide describes the correct sequence for a full Victorian terrace renovation — from structural works to final cleaning — with the key dependencies and common programme errors at each stage.

Phase 1: Enabling Works and Strip Out

Sequence:

1. 1.Asbestos survey and removal (if ACMs present — mandatory before any demolition)
2. 2.Scaffold erection (if required for roof or external works)
3. 3.Isolation of existing services (gas, electric, water) by licensed operatives
4. 4.Strip out: removal of existing fixtures, fittings, flooring, and non-structural partitions
5. 5.Structural demolition: chimney breast removal, party wall openings, load-bearing wall removal — always after temporary works are in place

Dependencies and errors:

• —Asbestos removal must precede all other demolition — working in ACM-contaminated debris is a health and safety offence and a prosecution risk
• —Services must be isolated before any structural demolition — cutting through a live electrical cable or gas pipe during wall removal has caused deaths on London renovation sites
• —Structural demolition sequence must follow the engineer's temporary works specification exactly — no deviation

Phase 2: Structural Works

Sequence:

1. 1.Temporary propping in accordance with structural engineer's design
2. 2.Structural openings cut (wall openings, floor penetrations)
3. 3.Steel beam installation and bedding on padstones
4. 4.Concrete structural works (new slab, underpinning)
5. 5.Structural engineer's inspection and sign-off
6. 6.Removal of temporary works (after sign-off)

Dependencies:

• —Building Control inspection of structural steel before any covering works
• —Party wall surveyor notification and compliance with any party wall award conditions on the method of working
• —Structural sign-off before temporary works are removed — the beam must be properly bedded and packed before the props come out

Phase 3: Roofing and External Envelope

Sequence:

1. 1.Roof repair or replacement (pitched or flat)
2. 2.External wall repairs (repointing, render repair, window and door replacement)
3. 3.New windows and external doors installed and made weathertight
4. 4.External drainage (gutters, downpipes, below-ground drainage connections)
5. 5.Building weathertight check before internal first fix begins

The critical weathertightness milestone:

Internal first fix — particularly plasterwork and electrical cabling — must not begin until the building is fully weathertight. Moisture entering through a roof under repair or through an empty window opening destroys new plaster, damages cables, and creates mould problems that persist for years. This milestone should be formally signed off by the site manager before first fix commences.

Phase 4: First Fix (Mechanical, Electrical, Plumbing)

First fix is the installation of all services within the building fabric — before walls are plastered and floors are screeded — so that the service runs are concealed.

Sequence within first fix:

1. 1.Structural penetrations for services — core drilling for ventilation ducts, pipe sleeves through walls and floors, conduit installation in concrete (if applicable)
2. 2.Heating first fix — underfloor heating pipe loops laid and pressure-tested; radiator tails; boiler/heat pump connections roughed in
3. 3.Plumbing first fix — hot and cold supply pipes, waste runs, soil stack connections
4. 4.Electrical first fix — containment (conduit), back boxes, cabling to all positions; consumer unit installed
5. 5.MVHR first fix — ductwork distribution throughout the building
6. 6.Building automation first fix — KNX/Lutron/AV cabling
7. 7.First fix inspection and sign-off — by architect and M&E engineer before any covering works

The coordination imperative:

First fix requires all MEP trades (plumber, electrician, heating engineer, MVHR installer, automation specialist) to work in a coordinated sequence rather than in parallel without communication. Uncoordinated first fix produces clashes — electrical conduit in the same ceiling void as MVHR ductwork; heating pipes crossing at exactly the point where a stud is needed. The MEP coordination drawing — showing all services in plan and section before first fix begins — is the tool that prevents this.

Testing before covering:

All pipework must be pressure-tested before screed or plaster covers it. Electrical cables must be continuity-tested. MVHR ductwork must be inspected for integrity. A leak discovered after screeding requires breaking out the screed to find and repair it.

Phase 5: Insulation and Airtightness

Sequence:

1. 1.Wall insulation (internal wall insulation boards or mineral wool in stud walls)
2. 2.Floor insulation (between joists or under screed)
3. 3.Roof insulation (between and below rafters for warm roof)
4. 4.Airtightness taping at all junctions, penetrations, and service entries
5. 5.Airtightness test (blower door test, if specified) — before plastering

Airtightness before plaster:

If an airtightness performance target has been set for the renovation (e.g. 5 ACH@50Pa), the airtightness test should be conducted before plastering so that any air leakage paths identified can be rectified while the fabric is still accessible.

Phase 6: First Fix Carpentry

Sequence:

1. 1.Stud partitions erected (non-structural)
2. 2.Door linings and frame sets installed
3. 3.Staircase structure installed (if new staircase)
4. 4.Subfloor preparation (levelling, acoustic treatment where required)
5. 5.Loft hatch and access panel installation

Coordination with MEP:

First fix carpentry creates the wall structure that MEP first fix runs within. Where stud partitions are installed after MEP first fix, cable and pipe runs must be coordinated with stud positions — a back box positioned where a stud will run is a defect that requires relocating either the box or the stud.

Phase 7: Wet Plaster and Screeds

Sequence:

1. 1.Underfloor heating screed (if liquid screed — must be poured before traditional plaster on walls, as wet screed against finished plaster causes staining)
2. 2.Sand-and-cement or traditional lime plaster (walls and ceilings)
3. 3.Skim coat (finish coat) — after sand-and-cement has dried sufficiently
4. 4.Plaster drying period (minimum 4–6 weeks for full drying before decoration)

Drying is not optional:

New plaster must dry fully before decoration begins. Decorating over wet plaster seals the surface, traps moisture, and causes paint to peel within weeks. In a programme under pressure to accelerate, the temptation to decorate early is high; the consequences are expensive. Adequate drying time must be built into the programme, not squeezed out.

Liquid screed (pumped anhydrite):

Liquid anhydrite screed is poured in a single operation and self-levels — ideal for large open-plan areas. It dries faster than traditional sand-and-cement screed (typically 1mm per day, with forced drying available). Anhydrite screed must be primed before tile adhesive application (the alkaline surface inhibits adhesion without primer). It must not be exposed to significant moisture during drying.

Phase 8: Second Fix Carpentry and Joinery

Sequence:

1. 1.Kitchen and utility unit installation (carcasses only — worksurfaces after plumbing second fix)
2. 2.Fitted wardrobe and bedroom joinery installation
3. 3.Internal doors hung on linings
4. 4.Skirting boards and architraves fixed
5. 5.Staircase balustrade and handrail installation
6. 6.Window boards (internal sills)

Sequence within second fix:

Doors are hung after skirtings are fitted — this avoids the skirting running under the door rather than up to it. Skirting runs after plastering is fully complete — plaster must be hard enough not to be damaged by nailing. Joinery is installed before floor screeds are polished or tiles are laid — the joinery contractor will inevitably make marks on the floor.

Phase 9: Second Fix MEP

Sequence:

1. 1.Plumbing second fix — sanitaryware, taps, shower enclosures, radiators
2. 2.Heating second fix — boiler/heat pump commissioning, filling and balancing system
3. 3.Electrical second fix — faceplates, light fittings, consumer unit connections
4. 4.MVHR commissioning — balancing airflows, commissioning controls
5. 5.Building automation commissioning — programming scenes, zones, schedules

Kitchen worksurfaces:

Stone worksurfaces (marble, granite, Dekton) are templated after kitchen unit installation (so the template matches the actual unit positions) and fabricated to order — typically 2–4 weeks from template. They are installed as part of second fix plumbing, as the final step before appliance commissioning.

Phase 10: Tiling and Stone Work

Sequence:

1. 1.Bathroom tiling (walls before floor — floor tiles run under wall tiles)
2. 2.Kitchen splashback and floor tiling
3. 3.Hallway and ground floor stone or tile laying
4. 4.Stair tiling or stone (last, as a heavily trafficked surface)

Protection:

Stone and tile floors must be protected immediately after laying — card, foam, or dedicated tile protection boards — and must remain protected until the building is handed over. An unprotected Calacatta marble floor with trades walking over it is a guaranteed restoration cost.

Phase 11: Decorating

Sequence:

1. 1.Fill, sand, prime (all walls and ceilings)
2. 2.First coat (walls and ceilings)
3. 3.Gloss or eggshell on woodwork (doors, frames, skirtings, windows)
4. 4.Final coat (walls and ceilings)
5. 5.Final woodwork coat

Sequence within decorating:

Ceilings before walls — to avoid cutting in twice when the ceiling coat drops onto the finished wall. Walls before woodwork — to avoid getting wall colour on finished woodwork. Woodwork before final wall coat — so any woodwork splashes are covered by the final wall coat. Final wall coat last — producing a clean, uncontaminated finish.

Phase 12: Floor Finishing

Sequence:

1. 1.Engineered timber or parquet laying (laid flat in acclimatised condition before heating is run)
2. 2.Floor sanding and sealing (oil or lacquer)
3. 3.Carpet laying

Engineered timber acclimatisation:

Engineered timber must be left in the building environment (not in a damp garage or unheated outbuilding) for a minimum 48–72 hours before laying. It must be laid before the underfloor heating is run up to operating temperature; after laying, heating is increased gradually (no more than 5°C/day) to prevent thermal shock cracking.

Phase 13: Soft Furnishings and Art

Sequence:

1. 1.Window track and pole installation (by electrician for motorised; by curtain fitter for manual)
2. 2.Curtain and blind hanging
3. 3.Furniture delivery and positioning
4. 4.Artwork hanging (by specialist art handlers)
5. 5.Accessories and styling

Phase 14: Commissioning and Snagging

Sequence:

1. 1.Full HVAC commissioning and test reports
2. 2.Electrical commissioning (EICR issued)
3. 3.Building automation full programming and demonstration
4. 4.Architectural snagging (architect's inspection against drawings and specification)
5. 5.Client walkthrough snagging
6. 6.Contractor snagging remediation
7. 7.Practical Completion certificate issued

The snagging programme:

Snagging is not a single event — it is a series of inspections at different stages, with the final snagging occurring at Practical Completion. Attempting to snag too early (before decoration is complete, before fitting out is done) produces a snagging list that is immediately obsolete. The right time for the final architectural snag is when the contractor has declared the building ready for handover.

Common Programme Failures

1. 1.Beginning internal works before the building is weathertight — the single most common and most costly programme error
2. 2.Decorating over wet plaster — producing paint failure within weeks
3. 3.Laying stone or tile before plastering is complete — trades traffic damages the floor
4. 4.Commissioning UFH before the screed has dried — screed cracks from thermal shock
5. 5.Installing kitchen before second-fix plumbing is complete — worktops must come out to access pipes
6. 6.Furniture delivery before decoration is finished — furniture damaged; walls and woodwork scratched

Each of these errors adds 2–6 weeks to the programme and costs proportionally. A well-run programme avoids all of them through disciplined sequencing and a site manager who enforces the sequence rather than allowing trades to jump the queue.