Renovating a house: where to start and the order of works

The order of works decides whether a renovation gets done once or twice. Plaster that goes on before the damp is fixed, or a kitchen fitted before the rewire, gets paid for again. We set out where to start, the 9 stages from survey to snagging, what needs approval in England, how long the main jobs take and what to budget, contingency included.

Where to start with a house renovation

Start with the house, not the finishes. Damp, roof defects, rotten timber and ageing electrics and plumbing decide how far the budget stretches, and a wet wall behind the plaster is far harder to spot than a dated kitchen.

Then split the scope in two. The essentials are whatever keeps the house dry, sound and safe: the roof, the damp, the structure, the wiring and the heating. Everything else is a wish list, priced once the essentials are known.

An architect earns their fee once the plan changes the layout, the structure or the outside of the house. A refresh inside the existing walls can be priced by a builder from a written scope, with a structural engineer brought in for a single beam.

The surveys to commission first

Commission a full building survey rather than a HomeBuyer-level report, because it reports on the structure and the defects, not just the value. On an older house, add a CCTV drainage survey, which films the drains from the inside, and an asbestos survey before anything is stripped out.

Damp is the first thing to settle. If the survey flags rising or penetrating damp, damp proofing and the cause behind it are dealt with before any new plaster goes on. Timber comes next: active woodworm in the joists or dry rot under a floor has to be treated or cut out before anything is built on top of it.

The order of works for a house renovation

Every renovation follows the same sequence, whether it covers one room or the whole house. Structural repairs, the roof, the services and the insulation go in before any finish, and anything wet or dusty happens before the work it would spoil.

On a big job the stages overlap. The roofer can be on the scaffold while the electrician runs cables inside. What never changes is that a stage waits until the work it will cover up is finished and checked.

Strip out and structural work

The strip out takes the house back to what is staying: old kitchens and bathrooms, blown plaster, redundant pipes and sometimes floorboards. It fills skips fast, so book the skip, and agree where it will stand, before day one.

Structural work happens while the house is open. A wall has to be assessed before it comes down, and a load-bearing one needs the right support in place before any demolition starts. Removing a chimney breast raises the same question, because the masonry above it still needs holding up.

On a terrace or a semi, structural work often touches the wall you share, and that brings in party wall notices. In England and Wales you must tell your neighbours before building work on or near the shared boundary. Scotland has different rules.

Roof, outside walls and windows

With the structure settled, make the shell weathertight. What the roof needs depends on the type of roof you have and the state of its covering, from refixing slipped tiles and renewing flashings to stripping and re-covering the lot.

Repointing belongs at this stage too. Worn mortar can look cosmetic, but joints that have failed let water into the wall, and that has to stop before new plaster goes on inside. New windows and external doors go in now as well, so the plasterer can finish the reveals around them. Re-roofing and new windows both need building regulations approval in England, which a registered installer can self-certify.

First fix: wiring, plumbing and heating

First fix is everything that ends up hidden: cables and back boxes, water and waste pipes, heating pipework, extractor ducting and any new stud walls. It needs the floors up and the walls bare, which is why it always comes before plastering.

If the survey or an electrician flags ageing electrics, a full rewire happens now. A new fuse box, or any change to the wiring near a bath or shower, needs building regulations approval, which a registered electrician self-certifies.

Plan the heating now too, even though the boiler goes on later. New radiators, a moved boiler or a combi conversion all change pipe runs that are easiest to lay with the floors up. A gas boiler must be fitted by a Gas Safe registered engineer, and a like-for-like combi boiler swap costs £1,800 to £3,500 fitted in 2026.

Plastering

With the services in, walls and ceilings are boarded, plastered or skimmed. Plaster is wet work, and paint cannot go on until it has dried, so the programme leaves a gap here. How long plaster takes to dry depends on the type of plaster, the thickness and how warm and ventilated the room is.

This is the last cheap moment to move a socket or a light. After plastering, the same change means cutting into a finished wall and making good.

Second fix: kitchens, bathrooms and fittings

Second fix connects everything the first fix left ready: sockets, switches and lights, radiators, the boiler, sanitaryware, the kitchen, internal doors, skirting and architraves. Kitchens and bathrooms go onto finished walls, and the boiler is commissioned once the system is filled.

Order the kitchen and bathroom early, because the lead time on units and sanitaryware often sets this stage's start date. A new bathroom involving plumbing also needs building regulations approval in England.

Decorating and flooring

Decorating starts once every trade that makes dust or drills holes has gone. New plaster takes a thinned mist coat first, then the finish coats. Floors go down last, or stay covered, so ladders and boots do not mark them.

Outside works

Outside work waits until the heavy traffic has stopped. A tarmac driveway or a new patio goes down once the skips, the scaffold and the delivery lorries have finished with the front of the house, so the new surface is not the one that takes their weight.

Snagging

Snagging is the final walk round, room by room, listing every defect for the builder to put right: a door that sticks, a cracked tile, a patch of paint that was missed. Write a snagging list before the final payment, and hold that payment until the list is cleared.

Where an extension or loft conversion fits in the order

Adding space does not change the sequence. The shell of an extension or a loft goes up during the structural stage, then its wiring, plumbing and plastering run with the rest of the house. You pay for one first fix and one round of plastering instead of two.

That holds for a two-storey rear extension, for a side return extension on a Victorian terrace and for an orangery or conservatory. Each starts with foundations, and each adds a room the heating and electrics have to reach.

Lofts start with the roof. Which of the types of loft conversion fits depends on the roof shape and the headroom, and the four take very different amounts of work:

• Roof light: a velux conversion adds windows in the existing slope and leaves the roofline alone, the least disruptive of the four.
• Dormer: a dormer loft conversion builds a box out from the rear slope for standing headroom, typically for around £50,000.
• Hip to gable: on a semi or an end terrace, a hip to gable conversion rebuilds the sloping side of the roof as a vertical wall.
• Mansard: a mansard loft conversion rebuilds the rear slope as a near-vertical wall, the biggest roof job of the four.

Extensions and lofts both involve structure, drainage, insulation and fire safety, so plan on building regulations approval before the shell goes up. Adding one after the renovation means a second strip out of the room it joins, and a second round of plastering and decorating.

Planning permission and building regulations for a renovation

Most internal renovation work needs no planning application, and neither do many like-for-like repairs. Planning comes in when the work changes the structure or the outside appearance of the house, or when the house is listed or in a conservation area.

Building regulations are a separate test, and they reach far more renovation jobs. The government's approval guide lists replacement windows and doors, new roof coverings, a new heating system, extra radiators, a new fuse box and a bathroom involving plumbing alongside the obvious building work.

Where you do need approval in England, the building regulations give three routes. A full plans application is decided within 5 weeks, or 2 months with your consent. A building notice suits smaller jobs and lets work start 2 days after it is submitted. The third is a registered installer who self-certifies, with a certificate due within 8 weeks. Whoever applies, you as the owner remain ultimately responsible for compliance.

What to budget for a house renovation

A renovation budget is the jobs on your scope plus the costs around them. These typical prices cover each job as a whole, before fees and contingency, and each moves with size, specification and the state of the house.

Adding up the jobs gives the build cost, but what a house renovation costs in the end also includes the lines around the build:

• Architect or designer fees, if the layout or the outside changes
• A structural engineer for any wall, beam or chimney breast
• Planning and building control fees, which each council sets
• VAT, where a quote is shown without it
• Skip hire and waste removal
• Decorating and finishing items the builder has not priced
• Somewhere else to live, or a temporary kitchen, if the house is out of action

Then add a contingency of 10 to 20% on top. The older the house, the likelier it is that opening a wall or lifting a floor turns up rotten timber, failing mortar or old wiring, so aim for the top of that range on a period property.

Much of the early money goes on work you never see again. The roof, the windows and the boiler can take a five-figure sum before a single room looks any different:

Renovating a home that has stood empty can qualify for a reduced 5% VAT rate on the builder's work and the building materials supplied with it, and so can converting a house into flats or flats back into a house. HMRC sets how long the home must have been empty, and the evidence it accepts, such as council tax and electoral roll records, in VAT Notice 708. Goods that are not building materials stay at the standard rate.

How long a house renovation takes

Each big job takes weeks on site, and the clock starts after design, approvals and ordering, not before them.

A whole-house renovation runs several of these, some side by side and some strictly one after another, so it is measured in months. On an older house, hidden defects move the finish date as well as the budget.

Living in the house during a renovation

If the house needs major work, renovating before you move in is usually simpler. Builders get free access, and the messiest jobs, such as rewiring, plastering and new floors, happen with nobody living around them. Renovate first when:

• The work is structural or whole-house. Walls coming out, a rewire or a new heating system leave rooms unusable for weeks.
• The kitchen and bathroom are both being replaced. Losing both at once makes daily life hard, even for a few weeks.
• The house is not safe to live in as it is. Dangerous wiring, no working heating or a leaking roof come first.
• You can carry two homes for a while. Rent or a mortgage elsewhere is part of the budget, and it grows if the job overruns.

Move in first and renovate in stages when:

• The work is mostly cosmetic: decorating, flooring, and a kitchen or bathroom one at a time.
• The budget has to be spread over time, so the essentials get done first and the finishes follow.

Phasing works as long as the order holds across the phases: structure, roof, services and insulation first, finishes last. Decorating a room that still needs rewiring means paying for the decorating twice.

Choosing a builder and agreeing the contract

For a whole-house job, one main contractor running the trades is the simplest route. Managing each trade yourself saves the contractor's margin, but it makes you responsible for the sequence, the deliveries and every gap between one trade leaving and the next arriving.

Get at least three quotes against the same written scope, so the numbers compare. Agree the price, a start date and a completion date before anyone starts. On a mid-size or large renovation, put it in a written contract, such as a JCT contract, rather than a chain of messages.

The most common renovation mistakes

• Starting without a fixed scope. Deciding as you go turns every choice into a priced variation.
• Budgeting for the build alone. Fees, VAT, skips and hidden repairs then come out of the contingency, or out of the finishes if there is none.
• Taking the lowest quote at face value. A missing line in a cheap quote comes back later as an extra.
• Finishing rooms out of order. Decorating before the rewire, or a floor before the plumber, means doing the finish twice.

Renovating in Scotland, Wales and Northern Ireland

Everything above follows the rules in England. Wales, Scotland and Northern Ireland run their own planning and building standards systems, so a renovation in Cardiff, Glasgow or Belfast follows its own nation's rules, even where the order of works is identical.