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What changes a timber frame extension price?
In Cheshire, a timber frame extension is priced like any other added room: foundations, frame, cladding, how it meets the old house, and the approvals. Ask the quote to name each of those, not only the kit.
Last reviewed:The frame is not the whole quote
In Cheshire, a timber frame extension is a way of holding up a new room. It is not a separate planning category, and it does not on its own tell you what the whole extension will cost. Firms sometimes lead with the frame because it is the part they manufacture. The quote you need also covers the hole in the existing wall, the ground, the skin of the building, the roof junction and the sign-off. No figure is printed, because we could not find two dated public sources that agree on one. Oak, softwood and a panel system are still different builds, so ask the quote to name which one it is.
Planning looks at the outside, not the studs
The Planning Portal's extension rules do not split "timber" from "masonry". They limit size, position and appearance. If you want to rely on permitted development, the materials used in any exterior work must be of a similar appearance to those on the exterior of the existing house [S1]. That sentence is the one to put in front of a cladding sample. A brick terrace with a new timber-boarded wing may need a householder application even when the depth would otherwise fit. Ask the council. Do not guess the outcome from the cladding sample.
The size tests still apply. Only half the land around the original house may be covered [S1]. A single-storey rear extension must not project more than four metres on a detached house, or three metres on any other house, and must not exceed four metres in height [S1]. Within two metres of a boundary, eaves must not exceed three metres [S1]. You cannot build forward of the principal elevation, or of a side elevation fronting a highway [S1]. On Article 2(3) designated land the work cannot include cladding of the exterior [S1]. That last point matters if the whole idea is a timber skin in a conservation area.
Side extensions must stay single storey, no more than four metres high, and no more than half the width of the original house [S1]. Upper storeys have their own projection and window rules [S1]. Flats are outside the householder rights [S1]. Earlier extensions count [S1].
The house extension page walks the full size list. On a timber-frame quote, ask about appearance, who designs the junction, and what supply of the kit leaves out.
Building regulations still cover the room
GOV.UK is plain that building regulations approval and planning permission are different, and that you might need both [S2]. The Building Regulations 2010 cover the construction and extension of buildings [S2]. Ordering a frame from a yard does not replace that. Insulation, structure, fire spread and the way the new room drains are questions for the designer and for building control.
If you cannot tell whether approval is needed, GOV.UK says check with a building control body [S2]. Name that body in the quote. If a competent person scheme will certify only the electrics or the windows, say so, and do not pretend the scheme covers the frame.
GOV.UK: find your local council for building control. QuoteZila is not affiliated with this organisation.
Ground, party walls and the kit
A lighter superstructure is not a reason to skip the ground. Ask what the frame stands on, who calculates it, and what happens if the trial hole shows fill or roots. Ask the quote for the trench depth rather than leaving it blank.
GOV.UK lists new building on or at the boundary of two properties, and excavation near to and below a neighbour's foundations, as work the Party Wall etc. Act 1996 can cover [S3]. Cutting into a party wall is one of the examples [S3]. Opening the back wall of a terrace to meet a new timber room can be that example. Where the Act applies, a party wall notice comes before the kit arrives. The Act is separate from planning and from building regulations approval [S3].
Ask the frame supplier and the site contractor to be named separately if they are different firms. A quote that says "frame delivered" and stops there has not priced the build.
Quote lines that belong on the paper
| Line | Question to ask |
|---|---|
| Design of the frame and the foundations | Who signs the drawings, and is the fee included? |
| Cladding and the "similar appearance" test | Will this board match the existing house closely enough for permitted development [S1]? |
| Insulation and membranes | Specified, or left as "to building control"? |
| Roof junction | Altering the existing roof can fall outside the extension class [S1] |
| Opening in the existing wall | Who props, who designs the support, who makes good? |
| Windows and external doors | Similar appearance, and which regulations they follow [S1] |
| Scaffold, crane or manual handling of the kit | Access in a Cheshire side passage is a site fact, not a town fact |
| Building control | Extensions are covered by the regulations [S2] |
| VAT | Registration when taxable turnover goes over £90,000 [S5] |
What to send
- Photos of the existing exterior, because appearance is the planning hinge [S1].
- House type and any extension already built.
- The depth you want, measured from the original rear wall.
- Whether the frame company and the builder are the same firm.
- The postcode, and how a long pack of timber would reach the garden.
Jobs you might post
These are examples, not taken from real job posts.
- "Brick semi in Nantwich. We want a single-storey rear room in a timber frame, but the outside must be discussed against the similar-appearance rule. Please price brick slips or render as well as boarding, and say which one you think needs an application."
- "Detached house. Timber frame, single storey, within the detached rear limit. Include foundations, the structural opening, insulation and building control. The frame supplier can be named separately from the site crew."
- "Terrace in Sandbach. Rear timber room. Please include a line for finding out whether a party wall notice is required before the back wall is opened."
How to compare frame quotes
Citizens Advice wants a written quote with a fixed total, a breakdown, and a statement of whether VAT is included [S4]. An estimate is only a rough guess [S4]. Collect at least three [S4]. A price that is a lot lower can mean the firm is not quoting for the same work [S4].
Ask to see insurance that lasts until completion, including cover if design work is part of the job. Citizens Advice distinguishes public liability from professional indemnity for design [S4]. Ask which of those the firm actually holds, and look at the documents [S4]. If they offer a guarantee, ask whether it is insurance-backed [S4].
Kit, site crew and the week the frame arrives
Ask for two names if two firms are involved: who manufactures or supplies the frame, and who stands it up, wraps it and joins it to the house. A delivery date without a site crew is a pile of timber in the garden. Say who is responsible if the kit is late, and who protects the house while the back is open.
Weatherproofing the junction is part of the build, not a snagging extra you discover in November. Ask for the roof junction and the damp proofing where the new floor meets the old wall to be written down. Ask the quote to name the membrane product, or to say that the junction detail is still to be designed.
If you want the outside to be boarding, bring a photo of the existing brick or render to the conversation. The similar-appearance test is about that photo, not about whether timber is fashionable [S1].
Official pages
QuoteZila is not affiliated with these organisations.
- Extension rules, including appearance: Planning Portal [S1].
- Building regulations: GOV.UK [S2].
- Party walls: GOV.UK [S3].
- Quotes, deposits, insurance: Citizens Advice [S4].
- VAT: GOV.UK [S5].
This page is general information, not professional or legal advice. QuoteZila does not check Gas Safe, WaterSafe, NFRC, NICEIC or other registrations against the register on your behalf: look them up yourself.
Where this applies. Appearance and size rules above are the Planning Portal's England householder account. They do not set a price for timber. Outside England, ask the local authority before you order a frame.
If the kit and the site crew are different firms, ask which of them stays responsible once the frame is standing and the back of the house is open to the weather. A delivery note is not the same document as a finished-room quote.
Ask for timber frame quotes
Describe the cladding and the town. Up to five matched local businesses can reply [QZ2]. QuoteZila is free for customers and local businesses [QZ1].
Honest status: QuoteZila is new. We're starting in Cheshire, beginning with Crewe, Nantwich and Sandbach, and growing area by area. Anyone in the UK can still post a job or register a business. How fast you get quotes depends on how many local businesses have joined near you. Businesses can register and receive jobs straight away. We don't check insurance, qualifications or registrations, so please check these yourself before you hire.
Posting a job is not open yet
The trade page for this work is builders. Carpenters may be part of the site team. Glaziers fit the glass. All services lists more.
Questions about timber frame extensions
How much does a timber frame extension cost in Cheshire?
The frame is one line. Foundations, cladding, insulation, windows, the junction with the existing house and building control are others. Ask each firm to price the same drawing.
Do timber extensions follow different planning rules?
The Planning Portal applies the same extension limits whatever the structure is made of. Exterior materials must be of a similar appearance to the existing house if you are relying on permitted development. A timber skin on a brick house may fail that test. The council decides, not the brochure.
Does the frame avoid building regulations?
No. GOV.UK says the Building Regulations 2010 cover the construction and extension of buildings. A factory-made frame is still an extension. Ask building control which details they want for structure, insulation and fire before the frame is ordered.
What about the boundary and next door?
New building on or at the boundary, and excavation near a neighbour's foundations, are among the works GOV.UK lists under the Party Wall etc. Act 1996. The Act is separate from planning permission. Where it applies, use a party wall notice.
Are foundations still required under a light frame?
Ask for a foundation design. A timber frame still has to stand on whatever the ground at your address needs. Ask the designer and building control what the ground at your address needs. The quote should name that design rather than leave a blank called 'frame only'.
How large a deposit is sensible?
Citizens Advice says you should try to avoid a deposit, that buying the materials yourself is one alternative, and that you should not agree more than 25% if you cannot avoid paying something up front. A timber kit can be a large material order, which is why the receipt matters.
Does QuoteZila check timber-frame firms?
No. We don't check insurance, qualifications or registrations, so please check these yourself before you hire. You can report a quote or a business from your job page.
Can I request timber frame quotes here?
Yes. Describe the room, the cladding you hope to use, and your Cheshire postcode. Up to five matched local businesses can send quotes. QuoteZila is free for customers and local businesses.
Related reading
- Roof repair cost: when the junction is really a roofing job
- Fencing cost: if the boundary is a fence, not a wall you are building on
- Builders
- All cost guides
Part of Cost guides. All services
Related trades
Cost guides
Related pages
- Two-storey extension: what changes the price. Two-storey extensions typically cost £1,000 to £2,500 per square metre in Master Builders guides. Compare drawings in Cheshire. QuoteZila does not set prices.
- Underpinning a house: what changes the price. In Cheshire, underpinning a house is priced from length, depth, access and the party wall. No pound total is printed. See who to ask before anyone digs.
Sources
- QZ1: QuoteZila product fact. QuoteZila pricing line.
- QZ2: QuoteZila product fact. QuoteZila FAQ.
- S1: Planning permission: extensions, Planning Portal. Accessed 2026-10-27. https://www.planningportal.co.uk/permission/common-projects/extensions/planning-permission/
- S2: Building regulations approval, GOV.UK. Accessed 2026-10-27. https://www.gov.uk/building-regulations-approval
- S3: Party Wall etc Act 1996 guidance, GOV.UK. Accessed 2026-10-27. https://www.gov.uk/guidance/party-wall-etc-act-1996-guidance
- S4: Before you get work done on your home, Citizens Advice. Accessed 2026-10-27. https://www.citizensadvice.org.uk/consumer/getting-home-improvements-done/before-you-get-building-work-done/
- S5: When to register for VAT, GOV.UK. Accessed 2026-10-27. https://www.gov.uk/register-for-vat