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What changes the cost of roof trusses?
The cost of roof trusses depends on the span and shape of the roof, the truss design, how many are needed, how they are delivered and lifted, and the work around them, such as stripping the roof covering and building control. This page does not print a price, because we could not find two dated public sources that agree on one.
Last reviewed:What roof trusses are
A roof truss is a triangular timber frame made in a factory to a design for one particular roof. Each truss spans from one outside wall to the other, and a row of them, braced together and fixed to the walls, forms the structure the roof covering sits on. The timbers inside the triangle, called webs, carry loads across the frame, which is why trusses can be lighter than a traditional roof but must not be cut or altered without a design.
People usually ask about truss prices for one of four jobs:
- A new roof on an extension, where trusses are designed and delivered for the new space.
- Replacing a roof, where the old structure is failing and the whole roof is rebuilt.
- Repairing damaged trusses, after rot, a leak, fire, or past cutting by a previous owner.
- A loft conversion, where the existing trusses have to be strengthened or replaced to create a room.
QuoteZila is starting in Cheshire, with Crewe, Nantwich and Sandbach among the first towns, and anyone in the UK can post a job. This guide does not print a truss price. We could not find two dated public sources that agree on one. It explains what the price depends on, and the rules that apply.
Trussed roof or cut roof?
Older houses usually have a cut roof, built on site from rafters, purlins and ceiling joists. Newer houses often have trussed roofs. The Planning Portal says homes built after the 1960s are more likely to have a roof truss rather than a timber framed roof, and that in this instance the loft may require structural support [S7].
The difference matters for cost. A cut roof can sometimes be adapted with new timbers. A trussed roof cannot simply have its webs removed, because each truss depends on them. Converting a trussed loft usually means new structural members, such as steel beams or new timber purlins, designed by an engineer, before any webs are taken out.
What changes a truss quote
| What changes | Why it matters | What to ask |
|---|---|---|
| Span and pitch | Wider and steeper roofs need larger trusses | What span and pitch have the trusses been designed for? |
| Truss type | Standard, attic and special trusses differ in size and timber | Which truss type, and who designs it? |
| Number of trusses | The roof length sets how many are needed | How many trusses are in the price? |
| Structural design | An engineer or truss designer must design the roof | Is the design and the paperwork for building control included? |
| Delivery and lifting | Trusses are large and may need a crane or a lot of hands | How will they be delivered and lifted into place? |
| Stripping the roof | Replacing trusses means taking off tiles, battens and felt | Is stripping and re-covering the roof included? |
| Bracing and fixings | Trusses need bracing and straps to the walls | Are bracing, straps and fixings included? |
| Insulation and ceilings | Ceilings below and loft insulation may be disturbed | Who makes good the ceilings and insulation? |
| Scaffolding and protection | Open roofs need safe access and weather protection | Is scaffolding included, and how will the house be kept dry? |
| VAT | Some builders are VAT registered [S6] | Does the total include VAT? |
The design, delivery and re-covering lines are where quotes most often differ. A price for the trusses alone is not a price for a new roof.
Building regulations and structural design
Roof structures are building regulations territory. GOV.UK says you must check whether your work needs approval before you start, and that a tradesperson registered with a competent person scheme can certify some kinds of work instead of you applying [S3]. For a new roof or a structural change, building control is usually involved.
For a loft conversion, the Planning Portal says building regulations approval is required to convert a loft into a liveable space, and that the regulations are applied to make sure the structural strength of the new floor is sufficient and the stability of the structure, including the existing roof, is not endangered [S1]. Warwick District Council's building control guidance says roof trusses should not be altered without the advice of a structural engineer. It says beams are commonly installed to support the new floor and strengthen the rafters, which allows the bracing sections of the trusses to be cut out [S2].
The Planning Portal says you must also find out whether the loft work falls within the Party Wall etc. Act 1996 [S1]. If you share a wall with a neighbour, ask your builder or surveyor whether a party wall notice is needed.
This page gives no steps for cutting, removing or altering trusses yourself. Ask a structural engineer or a builder working to an engineer's design.
GOV.UK: find your local council for building control. QuoteZila is not affiliated with this organisation.
You can read GOV.UK's guidance on building regulations approval before you start.
Damaged trusses
Trusses can be damaged by:
- Rot, usually from a long-term leak or poor ventilation.
- Past cutting, where someone removed webs to make storage space.
- Overloading, for example heavy storage or a water tank placed where the design did not allow for it.
- Fire or impact, such as a fallen tree.
Signs include a sagging roof line, cracks in ceilings below, doors upstairs that start to stick, or webs that are visibly cut, split or soft. If you see these, stop storing heavy items in the loft and ask a structural engineer or experienced roofer to look. Repairs may be a straightforward strengthening job or may need new trusses, but either should follow a design.
Bats and nesting birds
Roof spaces are used by bats and birds. GOV.UK says all bat species, their breeding sites and resting places are fully protected by law [S4]. It says you may need a survey by an expert to show what bats are present and how they use the building, and that if you cannot avoid harming them or their habitat, you can apply to Natural England for a licence [S4].
If you have seen bats around the roof, tell the builder before you get quotes. A survey, if needed, has to happen before the roof is stripped, and it can affect when the work can be done.
Safe working on the roof
Replacing trusses means the roof is open for a time, and people are working at height on an exposed structure. Ask each builder how they will:
- provide scaffolding with edge protection around the roof
- keep the house dry while the roof is open
- lift trusses safely, by crane or by hand
- protect neighbours, the drive and the garden
This page gives no steps for working at height. For what businesses must plan for, see HSE's guidance on work at height.
HSE: work at height. QuoteZila is not affiliated with this organisation.
Planning the order of work
A new or rebuilt roof is a sequence, and gaps in the plan cost time and money:
- Drawings and structural design, approved by building control where needed.
- Any bat survey, before the roof is opened.
- Scaffolding and edge protection.
- Stripping the old covering, if there is one.
- Delivery and fixing of the trusses, bracing and straps.
- Membrane, battens and the new covering.
- Gutters, fascias and soffits.
- Insulation, ceilings and making good inside.
Ask your builder who is responsible for each step, and when building control will inspect. Trusses are usually made to order, so ask how long the maker needs before delivery.
How to compare truss quotes
Citizens Advice says a quote is a fixed price and an estimate is a guess, and suggests getting written quotes from more than one trader [S5]. It also suggests asking to see a trader's insurance [S5]. For roof trusses, ask each builder to state:
- The drawings and design the price is based on, and who provides them.
- The number, type and span of trusses.
- Delivery and lifting, including any crane.
- Stripping, re-covering and any new tiles, battens or membrane.
- Bracing, straps and fixings.
- Building control, and how the work will be inspected.
- Scaffolding, edge protection and weather protection.
- Making good ceilings and insulation.
- Whether VAT is included. A business must register for VAT when taxable turnover goes over £90,000 [S6].
Ask for the price to be based on the engineer's or truss designer's drawings, so every builder is quoting for the same roof.
Jobs you might post
These are examples, not taken from real job posts.
- "Single-storey rear extension with plans approved. Need a builder to supply and fit trusses and a tiled roof."
- "Previous owner cut some of the roof trusses to make storage space in the loft. Need a structural repair."
- "Thinking about a loft conversion in a 1980s semi with a trussed roof. Want quotes that include the structural design."
Give the drawings if you have them, the type of house, what is wrong or what you want to build, and whether you have seen any bats.
Get quotes for roof trusses
Describe the roof and your postcode. Up to five matched local businesses can send you a quote [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
See roofers, builders, joiners and carpenters for the trades involved. The roof repair cost guide covers smaller roof jobs, and what a strip foundation is covers the other end of an extension.
Questions about roof truss prices
How much do roof trusses cost?
This page does not print a figure. The span and pitch of the roof, the truss design, the number needed, delivery and lifting, stripping and re-covering the roof, and structural design all change the total. Ask for itemised written quotes based on the same drawings.
Can I cut roof trusses to make loft space?
Not without a structural design. Warwick District Council's building control guidance says roof trusses should not be altered without the advice of a structural engineer, and that beams are commonly installed to support the new floor and strengthen the rafters so the bracing can be cut out. This page gives no steps for altering trusses.
Do new roof trusses need building regulations approval?
New roofs and structural alterations usually do. The Planning Portal says building regulations approval is required to convert a loft into a liveable space, and that the stability of the structure, including the existing roof, is not endangered. GOV.UK says you must check if you need approval before you construct or change buildings.
What is the difference between a trussed roof and a cut roof?
A trussed roof uses factory-made triangular frames, each one designed to span from wall to wall. A cut roof is built on site from rafters, purlins and other timbers. The Planning Portal says homes built after the 1960s are more likely to have a roof truss rather than a timber framed roof.
What are attic trusses?
Attic trusses are trusses designed with an open space in the middle, so the roof can be used as a room. They are often chosen for new extensions or rebuilt roofs where a room in the roof is wanted. They are larger and heavier than standard trusses, so ask the designer whether they suit your walls.
What if there are bats in my roof?
GOV.UK says all bat species, their breeding sites and resting places are fully protected, and that you may need an expert survey and a Natural England licence if you cannot avoid disturbing them. Tell the builder if you have seen bats, and get advice before roof work starts.
Does QuoteZila check the businesses?
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.
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.
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- Roof Valley Work: What a Quote Should Name. A roof valley in Cheshire is the channel where two slopes meet. This guide prints no valley price. It shows what to compare: length, lining, tiles and access.
- Slate Roof Work in Cheshire: What to Ask. A slate roof quote in Cheshire turns on area, pitch, access and the timber under the covering. Compare written quotes for the same slopes.
Sources
- QZ1: QuoteZila product fact. QuoteZila home and jobs-for-tradesmen copy.
- QZ2: QuoteZila product fact. QuoteZila FAQ and app README.
- S1: Is building regulations approval needed for a loft conversion?, Planning Portal. Accessed 2026-10-27. https://www.planningportal.co.uk/permission/common-projects/loft-conversion/is-building-regulations-approval-needed-for-a-loft-conversion
- S2: Loft conversions, Warwick District Council. Accessed 2026-10-27. https://www.warwickdc.gov.uk/info/20375/building_regulations/1067/extensions_and_conversions/3
- S3: Building regulations approval, GOV.UK. Accessed 2026-10-27. https://www.gov.uk/building-regulations-approval
- S4: Bats: protection, surveys and licences, GOV.UK (Natural England). Accessed 2026-10-27. https://www.gov.uk/guidance/bats-protection-surveys-and-licences
- S5: 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/
- S6: Register for VAT, GOV.UK. Accessed 2026-10-27. https://www.gov.uk/register-for-vat
- S7: Planning a loft conversion, Planning Portal. Accessed 2026-10-27. https://www.planningportal.co.uk/permission/home-improvement/project-advice/project-advice-loft-conversion/planning-a-loft-conversion/