Key Takeaways
- Start with a clear brief and budget, including a 10 to 15% contingency, and 20% in a pre-1919 London house.
- Allow 6 to 9 months of planning before a whole-house start date, and 8 to 12 weeks for a project needing no application.
- Sort design and permissions before committing to a build date. A householder application costs £548 and takes around 8 weeks (MHCLG, 2026).
- Serve party wall notice two months ahead for work to a shared wall. This is the item that most often moves a London start date (gov.uk, 2026).
- Choose a builder on references, records and certificates, then agree an itemised quote and a written contract with staged payments and a 5% retention.
- Sequence the work correctly and order long-lead items early, because rework and waiting are the two expensive kinds of delay.
A renovation that runs smoothly is almost always one that was planned well, and most of that planning happens months before anyone arrives with a tool bag. This step-by-step guide takes you from first idea to handover: what to do, in what order, how long each part takes in London, and what to watch for.
1. Set your brief and budget
Write down what you want to achieve, how you actually use the space, and what success looks like when it is finished. A brief is not a mood board. The useful version says how many people cook at once, where the coats and the buggy go, whether you need a desk that closes, and which three things you would not sacrifice if the budget tightened. Every later decision gets measured against it, which is what stops a project drifting.
Then set a realistic budget. The builder's quote is the build cost, not the total: professional fees add 10 to 20%, VAT adds 20% on most work to an existing home, and a contingency of 10 to 15% sits on top, or 20% in a pre-1919 property that has never been opened up. Our budget and contingency guide sets out the full stack, and full house renovation costs in London gives the per m² rates to sense-check against.
How far ahead should you start planning?
Six to nine months before your intended start date for a whole-house renovation, and eight to twelve weeks for a project that needs no planning application and no party wall notice. The table below counts backwards from day one on site.
| Stage | When, counting back from the start date | Typical duration |
|---|---|---|
| Brief, budget and feasibility | 6 to 9 months before | 2 to 4 weeks |
| Measured survey and design | 5 to 7 months before | 2 to 4 weeks |
| Planning application, where needed | 4 to 6 months before | Around 8 weeks from validation |
| Structural calculations and building control | 3 to 4 months before | 1 to 3 weeks, up to 8 for full plans |
| Party wall notices served | 2 to 3 months before | 1 or 2 months, plus 14 days to reply |
| Tender, itemised quotes and contract | 2 to 3 months before | 3 to 6 weeks |
| Long-lead orders and borough licences | 1 to 3 months before | 6 to 12 week lead times |
2. Design and permissions
Arrange a measured survey, develop the design, then confirm what approvals you need before you fix a build date. Many projects fall under permitted development, others need planning permission at £548 from 1 April 2026 with a decision in around 8 weeks, and almost all need Building Regulations approval whether or not planning is involved.
The trap is assuming those three are one process. They are not: planning decides whether you may build it, Building Regulations decide how it is built, and the Party Wall Act is a private matter between you and your neighbour. A knock-through under permitted development needs no planning application at all, but it still needs a Part A structural calculation, a building control inspection and, in a terrace, a party wall notice. See our knock-through guide.
What actually gates a London start date?
Four things, and none of them respond to being chased. Build them into the programme rather than discovering them.
- Party wall notice periods. Two months for a party structure notice, the one you need to cut a steel into a shared wall or take a chimney breast off it, and one month for a line of junction or adjacent excavation notice. Your neighbour has 14 days to reply and silence counts as dissent, which brings surveyors in at £900 to £2,700 per adjoining owner. Notice stays valid for a year, so serve it as soon as the design is settled. See the Party Wall Act explained.
- Borough licences. A skip on the highway needs a permit, pavement scaffold needs a licence, and a parking bay suspension is charged per bay per day. Each borough sets its own fees and notice period.
- Restricted working hours. Most London boroughs limit noisy work to roughly 08:00 to 18:00 on weekdays and 08:00 to 13:00 on Saturdays, with nothing on Sundays or bank holidays. A site that loses an afternoon cannot make it up in the evening.
- Consents you did not know you needed. An Article 4 direction or a conservation area can remove permitted development rights street by street, and in a flat the freeholder's consent takes weeks and has to start before you book anyone.
3. Choose your builder carefully
Select on records, references and recent comparable work rather than the lowest price. The checks below take about twenty minutes and are the most valuable twenty minutes in the project.
- Companies House, to confirm the company is active and the person quoting you is a director.
- The public liability certificate itself, checking the insurer, the sum insured, the expiry date and that the name matches the company quoting.
- Trade registers: Gas Safe for gas work, and NICEIC, NAPIT or ELECSA for Part P electrical work. Federation of Master Builders membership involves an independent inspection, and TrustMark is the government endorsed scheme.
- A finished project of similar type and value, seen in person, plus two past clients you telephone rather than email.
Then get three itemised quotes on identical scope and ask each contractor how many days they have allowed. On work where labour is half the bill, a quote thousands below the others is pricing fewer days on site, not a better deal. Agree a written contract covering scope, price, programme, how variations are priced, insurance and retention, with payments tied to completed stages and a 5% retention held until snagging is done. Never pay in full up front. See choosing a builder in London.
4. Sequence the work
Renovation follows a logical order, because each stage buries the one before it and getting back to it costs many times what doing it in turn would have:
- Strip out and enabling works
- Structural and external works
- First-fix plumbing and electrics
- Plastering, then drying out
- Second-fix, flooring and joinery
- Kitchen and bathroom fitting
- Decoration and snagging
The decisions that stall a site are made at first fix, not at the end: every socket, switch and light position, which side the shower valve sits, whether the island gets power and waste. Order long-lead items in parallel, because kitchens, bespoke joinery, stone worktops and made-to-measure windows carry 6 to 12 week lead times and a ten week wait found in week nine stops everything. Our order of works guide covers each stage and what it depends on, and how long a renovation takes gives the durations.
5. Manage, snag and hand over
Set a rhythm early and keep it. A short weekly site meeting at the same time each week, a written record of decisions, and every variation priced and agreed in writing before it is carried out will prevent most of the arguments a renovation is capable of producing. Expect to make decisions promptly, because a decision the builder is waiting on is the cheapest delay to fix and the easiest to let drift.
Decide early whether you are staying in the house, because it changes both the programme and the sequence: living in through services work typically adds 30 to 50% to that part of the job. See living in your home during a renovation.
Finish properly. Work through a room by room snagging list before you release the retention, and collect the paperwork: the building control completion certificate, the Part P electrical installation certificate, Gas Safe notification and FENSA or Certass certificates for any windows. Your buyer's solicitor will ask for all of it one day. Also worth reading before you start: renovation mistakes to avoid.
Using one accountable team for design and build keeps the whole process coordinated, from consents through to handover. For a free consultation on your project, whether that is a whole-house renovation or structural alterations in London, contact us or call 07472 424 226.