September 10, 2026
What Is a Turnkey Home? A UK Guide
A turnkey home is delivered finished and ready to live in. The building is complete, the services are connected, building control has signed it off, and nothing remains on handover day beyond turning the key. That part is simple. The complication is that turnkey is not a regulated term in the UK, so what one company includes under it and what another includes can differ by tens of thousands of pounds.
What are turnkey homes in the UK?
Turnkey homes sit at one end of the self build spectrum rather than outside it. Government guidance on self-build and custom housebuilding describes projects ranging from individuals building or managing construction from beginning to end, through to individuals who commission their home, make the key design and layout decisions, and have it built ready for occupation. That last description is turnkey.
The legal test is whether the initial owner has primary input into the final design and layout. Meet it, and a turnkey home still counts as self build under the Self-build and Custom Housebuilding Act 2015. That opens the Community Infrastructure Levy exemption, though only where the forms are submitted and acknowledged before development commences. Buy a home off plan with no design input and none of this applies.
What is the difference between a turnkey home and a developer new build?
Both arrive finished. The difference is who decided what got built.
| Turnkey home | Developer new build | |
|---|---|---|
| Design input | Yours, from the brief onwards | Chosen from standard house types |
| Specification | Your choices throughout | Limited to an options list |
| Built for | You specifically | The general market |
| Plot | Usually one you have secured | Part of a wider development |
| Counts as self build | Yes, where you have primary design input | No |
With a turnkey home you decide what gets built and someone else builds it. With a developer’s new build, both decisions were made before you arrived.
What should a turnkey price include?
Because the term has no standard definition, scope is where the money and the risk both sit.
Normally included: design, planning, structural engineering, building control, groundworks, the full envelope, all services, kitchen and bathrooms, flooring, joinery, decoration, utility connections and handover.
Normally excluded: furniture and window dressings, and often driveways and landscaping.
Those exclusions are the usual grey areas, and they are worth confirming in writing rather than assuming either way. Our quotes are fixed price and include professional fees and VAT unless the design or specification changes.
What does a turnkey home cost?
UK build costs for 2026 generally run between £1,800 and £3,500 per square metre for the construction work, before land, driven more by specification and site conditions than by floor area. A turnkey price sits toward the upper end of that, because it covers considerably more than a shell. What it should not do is exceed the sum of its parts by a wide margin, and if it does, ask what the difference is buying you. Our self build house cost guide breaks the total budget down across plot, fees, build and contingency.
Is turnkey more expensive than managing the build yourself?
Not reliably. Self managing removes a management cost from the quote and adds the risk of sequencing errors, missed lead times and trades arriving to a site that is not ready for them. A twenty week lead time on windows, handled late, stops a programme dead and every following trade with it. Handled early, it costs nothing.
Are turnkey modular and prefab homes different?
The delivery method is different. The definition is not.
Modules are manufactured in a factory, delivered, assembled, then finished to a ready to occupy standard. They reach weathertight quickly, and the panels are made to consistent tolerances, though airtightness is still won or lost at the module joints and foundation interfaces, which are site work. Access and craneage rule out plenty of plots, and the design has to be locked down earlier because changes get expensive once production starts.
One thing matters more than any of that: a supplier delivering a weathertight shell has not delivered a turnkey home. Groundworks, connections, internal finishing and external works all remain site based.
What does turnkey delivery involve in practice?
At Lillingstone Lovell, a horseshoe shaped stone bungalow became a 3,000 square foot family home. Three parts of that project show what a turnkey contract covers.
The consent work. Requirements mapping with the client, design options with our architect, full planning and building control submissions, and the structural engineer managed throughout. When the client’s needs changed mid build, we made a separate balcony application rather than telling them it was too late.
The technical scope. A super insulated envelope with high performance glazing, underfloor heating across roughly 390 square metres, heat recovery ventilation, and an air source heat pump running with solar PV and battery storage.
The part nobody sees. A clay site with flood risk needed a deep interception drain and sub floor pumps before any of the above could work.
At Bicester we picked up a serviced plot from the developer’s foundation slab and finished it through to decoration, beating the site’s airtightness target with an internal parge coat, extra sealing at every opening and triple glazing. Both are in our case studies section.
What should you check before appointing a turnkey builder?
- Is the price fixed, and what triggers a variation?
- What exactly is included? Kitchens, bathrooms, flooring, decoration, driveways and landscaping specifically.
- What is the specification allowance, and what happens if you exceed it?
- Are the trades employed or subcontracted? Ours are on our own payroll, not brought in per job.
- Who handles building control? On a turnkey contract, it should be the builder.
- What warranty comes with the finished house?
A turnkey quote that looks cheaper than another is frequently covering less. Compare scope, not headline figures.
How long does a turnkey home take?
Design and build projects typically run six to eighteen months from first consultation to completion, based on current Cognitive Construction project timescales and subject to planning and site survey. Planning accounts for eight to twelve weeks of that and is largely outside anyone’s control once submitted. Procurement lead times account for more than most people expect, and unlike planning they are manageable if handled early.
What to do next
- Write down what finished means to you, room by room.
- Confirm your plot has planning permission or is capable of getting it.
- Ask any builder to confirm scope in writing before you compare prices.
- Check whether their trades are employed or subcontracted.
- Get a fixed price quote with the full scope attached.
Cognitive Construction delivers turnkey coordinated bespoke builds and design and build projects across Milton Keynes, Buckingham, Newport Pagnell, Olney, Woburn Sands, Bedford, Northampton, Aylesbury, Luton and Leighton Buzzard. We are a vetted member of the Federation of Master Builders, independently assessed on workmanship, customer service and financial standing, and our 10 Point Guarantee is signed personally by our Managing Director. See our accreditations.
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