Last updated: September 2026
Most building work in England has to comply with the Building Regulations 2010, which are made under powers in the Building Act 1984. Approved documents give guidance on how the requirements can be met. This guide sets out, for dealers who supply log cabins, glulam houses and other timber buildings to the UK market, what the regulations ask and where the figures come from. It was checked against the sources in September 2026. The guide covers England; Wales, Scotland and Northern Ireland have their own rules and guidance.
Which Parts of the Building Regulations Matter for a Timber Building?
Schedule 1 to the Building Regulations 2010 sets the requirements in parts. For a timber building that is not exempt, these parts are among those that can apply:
- Part A: Structure
- Part B: Fire safety
- Part C: Site preparation and resistance to contaminants and moisture
- Part F: Ventilation
- Part L: Conservation of fuel and power
- Part O: Overheating
- Part P: Electrical safety
Which parts apply to a project depends on the building, its use and the work. It is confirmed with building control.
How Do Part L Energy Requirements Affect Timber Buildings?
Limiting U-Values for a New Dwelling
Approved Document L, Volume 1 (Dwellings) sets limiting U-values for the fabric of a new dwelling. The table gives the values of the 2021 edition incorporating 2023 amendments, Table 4.1. They are area-weighted averages.
| Building element | Maximum U-value, W/(m²K) |
|---|---|
| Roof, all types | 0.16 |
| Wall | 0.26 |
| Floor | 0.18 |
| Party wall | 0.20 |
| Window | 1.6 |
| Rooflight | 2.2 |
| Doors, glazed doors included | 1.6 |
The same table limits the air permeability of a new dwelling to 8.0 m³ per hour per m² at 50 Pa.
The limiting values are not the whole requirement. A new dwelling also has to meet the target primary energy rate, the target emission rate and the target fabric energy efficiency rate, and the approved document notes that, to meet the target fabric energy efficiency rate, some elements need to be significantly better than the limiting values.
The 2026 Edition
The 2026 edition of Approved Document L, Volume 1 takes effect on 24 March 2027 for building work in England that is not in connection with higher-risk building work, and on 24 September 2027 for work that is. Its Table 3.1 keeps the limiting U-values listed above. The transitional arrangements are set out in Circular Letter 01/2026, published on gov.uk.
What This Means for a Timber Wall
Eurodita publishes preliminary U-values for the timber wall element alone: from 3.82 W/m²K for a 28 mm wall to 0.49 W/m²K for a 220 mm glulam wall. They are not a figure for a finished building and not a compliance result. For a heated dwelling the wall is part of a complete build-up with insulation that the buyer specifies locally, for example in twin-skin construction, and the thermal performance of that build-up is calculated for the project by the designer or the energy assessor.
What Do Part B and Part A Ask?
What Part B (fire safety) asks of a timber building depends on its use, its size, its height and its distance to the boundary. Fire resistance is established by test or calculation for the specific assembly; it is not inferred from a wall thickness. Requirements are confirmed with the designer, the fire engineer or building control before finished compliance is quoted.
Part A (structure) requires a building to be constructed so that the combined dead, imposed and wind loads are sustained and transmitted by it to the ground safely (requirement A1). Structural calculations, where a habitable timber building requires them, are carried out by specialist partners working with Eurodita, and the scope is confirmed in the written quotation. A foundation is designed locally for the ground and the loads of the project.
When Are Building Regulations Not Required?
Schedule 2 to the Building Regulations 2010 lists the exempt buildings and work. Two classes matter for garden buildings:
- Class 6, small detached buildings: a detached building with a floor area of no more than 15 m² that contains no sleeping accommodation; and a detached single-storey building with a floor area of no more than 30 m² that contains no sleeping accommodation, when no point of it is less than one metre from the boundary of its curtilage or when it is built substantially of non-combustible material
- Class 4, temporary buildings: a building which is not intended to remain where it is erected for more than 28 days
An exemption from the Building Regulations is not an exemption from planning permission. These are separate regimes. Dealers should advise customers to verify both with their local authority.
How Should Dealers Advise Their Customers on Compliance?
Before the Order
- Early contact: encourage customers to speak to their local planning authority and to building control before they commit to a specification
- Intended use: ask whether the building will be heated and whether anyone will sleep in it; both change what applies
- Documents: provide the product specification, the drawings and the project data for local review
Product Specification Support
Eurodita supplies the timber building kit with its drawings and with the technical data that is available for the order, for solid timber and for glulam alike. Dealers can request project-specific support from the Eurodita sales team.
Common Compliance Pitfalls
- Underestimating energy requirements: specifying single-wall construction without checking how building control will assess the complete build-up where Part L applies
- Informal foundations: assuming that a lighter timber building needs no designed foundation
- Ignoring settlement: not allowing for the settlement of solid log walls around openings and at connections to rigid elements
- Gaps in the fire file: not confirming which fire-performance or material data is available for project review
- Ventilation: specifying an airtight envelope without a ventilation strategy
Frequently Asked Questions
Do garden offices require building regulations approval?
A detached garden office with a floor area of no more than 15 m² that contains no sleeping accommodation is exempt under Schedule 2, Class 6. Up to 30 m² a detached single-storey building without sleeping accommodation is exempt when it stands at least one metre from the boundary or is built substantially of non-combustible material. A building with sleeping accommodation is not covered by Class 6.
What fire resistance does solid timber achieve?
The fire resistance of a wall or a structure is established by test or calculation for the specific assembly; it is not inferred from a wall thickness.
Are there different regulations in Scotland?
Yes. Scotland has its own building standards system with its own technical handbooks, and Wales and Northern Ireland have their own regulations. Dealers who supply those markets should read the rules of the nation concerned.
Questions About Eurodita Supply
Does Eurodita publish U-values for its solid or twin-skin walls?
No. Eurodita publishes U-values for the timber wall element alone, not for a finished wall. Twin-skin build-ups of 44-50-44, 44-100-44, 58-50-58 and 58-100-58 mm are supplied with the cavity insulation bought locally, so the thermal performance of the finished wall depends on the insulation, membranes, glazing, roof and floor chosen for the project. Those calculations are prepared by the project designer or SAP assessor, and Eurodita supplies the timber specification for that work.
Does Eurodita provide structural calculations for Part A compliance?
Structural calculations, where a habitable timber structure requires them, are carried out by specialist partners working with Eurodita, and the scope is confirmed in the written quotation. Timber is Nordic and Northern European spruce and pine, machined on Hundegger CNC lines. Local review and acceptance remain with the buyer's structural engineer and building control route.
Are Eurodita timber buildings CE marked or certified for the UK?
Eurodita makes no blanket CE or UKCA claim and holds no own FSC, PEFC or ISO 9001 certification. Fire performance is established by test or calculation for the specific assembly, not by the manufacturer's wall thickness. The technical documentation and any test data available for a particular order are confirmed at quotation. Dealers should not describe the range as certified.
Which Eurodita wall build-ups are meant for habitable UK dwellings?
For a heated dwelling that must satisfy Part L, the post points to twin-skin construction. Eurodita offers 44-50-44, 44-100-44, 58-50-58 and 58-100-58 mm twin-skin build-ups, and glulam profiles of 70x130, 88x260, 135x260, 180x260 and 220x260 mm. A solid log model can be made in any of the 28, 34, 44, 58 and 70 mm profiles, and a glulam model in any glulam profile; the final envelope is assessed by the project designer.
What does Eurodita supply for a UK residential project, and what stays local?
Eurodita manufactures the timber building kit and its joinery, ships it flat packed on EXW Eurodita factory terms by default, and supplies drawings and available technical data. Installation and how it is organised is agreed per project. Foundations, utilities, heating systems and MVHR stay with the local team of the buyer, and turnkey delivery is not part of the standard supply. Building approval stays with the buyer's local route. Unloading at site is the buyer's responsibility, and Eurodita runs no transport fleet.