3 building regulation changes affecting external door specification this year
- June 1, 2026
- News
If you’re specifying wooden external doors on a new build or conversion in 2026, three approved documents have changed what compliance looks like. Part L has tightened U-value declarations, Part Q faces expansion beyond new builds, and Approved Document M continues to set dimensional requirements that affect every front door you order. Here is what each change means in practice, and where solid hardwood doors sit against each threshold.
Our range of wooden external doors at Country Hardwood
Before covering the regulations, it helps to understand what we offer. Country Hardwood manufactures bespoke hardwood external doors from a Buckinghamshire workshop, supplying contractors and developers across the UK.
We design, manufacture, and install made-to-measure timber doors for period and modern homes.
Timber species include European Oak, Sapele, Accoya®, and Iroko
Our timber front doors and stormproof door range are built to UK conditions.
Glazing runs to 28mm double-glazed units on stormproof models, with conservation glazing options available.
Security uses multi-point locking on French and stormproof doors.
Regulation 1: Part L and the shift to per-door set U-value declarations
Part L deals with the conservation of fuel and power in buildings; in other words, it ensures buildings are energy efficient.
The change that affects specification now is how U-values are declared.
The Future Homes Standard consultation proposed that U-values should be declared for each individual external door set, and window supplied to new-build projects. This would replace the current method where a single U-value calculated for a representative ‘model’ product is used across a range.
Manufacturers will need access to a tool capable of calculating U-values for each product, factoring in variables such as size and configuration.
Hardwood doorsets with quality seals and 28mm double-glazed units are well-placed to hit the required thresholds. The natural insulating properties of dense hardwoods like oak and Accoya® reduce thermal bridging at the frame.
Contractors should ask manufacturers for per-doorset thermal data now, ahead of full Future Homes Standard enforcement. Country Hardwood can supply product-specific performance data on request.
Regulation 2: Part Q security – expansion beyond new builds
Building Regulations Part Q outlines standards for the strength and durability of external doors and windows to prevent forced entry.
Currently, Approved Document Q applies only to new-build dwellings.
That scope is proposed to change.
The proposed changes would require all entrance doorsets and accessible windows, whether for new builds or existing buildings, to meet an enhanced security standard, such as PAS 24.
Approved Document Q mandates that all easily accessible doors must be robust enough to resist physical attack by a burglar. To comply, doors must be tested to PAS 24, which involves independent labs attacking the door with crowbars, cutting tools, and impact rams. If it survives for a set time, it passes.
Manufacturers will need to ensure their product ranges are covered by enhanced security testing or have access to third-party test evidence from a hardware supplier that meets building control requirements.
Country Hardwood’s stormproof doors are made from the finest timber and are resistant to twisting and warping, creating a stable product.
Each door is hand finished and provides protection against severe weather and superb security with multipoint shoot locking bolts.
For developers planning conversions or refurbishments, it is worth specifying PAS 24-rated hardware on all ground-floor timber doorsets now, given the direction of travel in the regulations.
Regulation 3: Approved Document M – access dimensions for external doors
Approved Document M covers requirements for doors in dwellings and non-domestic buildings, aiming to ensure they are accessible and usable by all individuals, particularly those with disabilities or limited mobility.
Part M states that external doors should have a minimum door width of 775mm to allow wheelchair access, with a recommended width of 850mm for main doors. Thresholds should be flush or have a maximum height of 15mm to prevent tripping hazards.
Handles should be easy to use, preferably lever type, positioned at accessible heights generally between 900mm and 1100mm above floor level.
Standard off-the-shelf doors from many brands come at widths that fall below the recommended 850mm for front doors.
Country Hardwood offers standard and bespoke sizes across external doors, both single and double.
Bespoke manufacture means the clear opening width, threshold detail, and ironmongery height can all be specified to meet Part M from the outset, avoiding costly site adjustments.
How these three regulations interact on a single doorset
On a new-build residential project, a front door now needs to satisfy all three documents simultaneously:
- Part L: Per-doorset U-value at or below 1.6 W/m²K, with thermal bridge data
- Part Q: PAS 24 security testing across the doorset assembly
- Part M: 775mm minimum clear width, max 15mm threshold, lever hardware at correct height
Specifying wooden external doors that hit all three is achievable with the right manufacturer.
Hardwoods such as oak and sapele, alongside modified timbers like Accoya, offer stability, durability, and crisp detailing.
Whether you’re matching originals or upgrading a dated entrance, Country Hardwood can replicate features and proportions while bringing performance up to current standards.
Explore our full timber door range or contact the team for a specification pack with thermal data and security details for your project.
If you’d like to find out more about how the team at Country Hardwood can help you to ensure that all your projects meet current building regulations requirements, get in touch today. You can call us on 01296 714 314 or send us a message online and we’ll get back to you as quickly as possible.
