Windows, Doors & Glazing
248 sources in the library on windows, doors & glazing, 12 on this page cited in a published note. Each one says what the document covers and what it is good for. Name a source to see which document it is and where to read it. One at a time. Page 3 of 7.
- supplier figure RN-83UZWJ cited
Toolstation
Toolstation product page for a Yale Platinum BSI Kitemarked 3-star 40/50 euro cylinder at £59.99 including VAT, the top of the note's £30–£60 range for 3-star cylinders.
Cited in How to Change Upvc Door Lock.
- supplier figure RN-NOQOQP cited
VELUX
Velux UK's care and maintenance guidance for roof windows, including annual clearing of the flashing, air filter cleaning and pane care.
Cited in Velux Window Repair: Leaks, Problems & Costs, Velux Window Servicing: Cost & What's Involved.
- supplier figure RN-638OAE cited
VELUX
VELUX's UK find-an-installer page lists VELUX Certified Installers and explains that they are independent contractors, which settles that Velux publishes a list of certified installers on its website.
Cited in Roof Window Sizes Explained (Velux Codes), Velux Window Servicing: Cost & What's Involved.
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VELUX
VELUX's product page for its standard pitched roof window. It states each operating version is suitable for roof pitches of 15 to 90 degrees.
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VELUX
Velux UK's guarantee page, giving 10 years for roof windows, 5 years for electrical components (extendable by registration) and 3 years for blinds.
Cited in Velux Window Repair: Leaks, Problems & Costs, Velux Window Servicing: Cost & What's Involved.
- supplier figure RN-XUFUIQ cited
VELUX
The current UK Velux product guarantee document, which lists roof windows including their glazing units under the same 10-year guarantee period.
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VELUX
Velux UK's accessories page for its DIY service kits, which states Velux's recommendation to lubricate fittings and hinges at least annually.
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Vufold
The maker's product page for its Supreme 3.0 m by 2.1 m aluminium bifold door set, with its supply-only price. Replaces a footnote to the category listing, which the site does not cite.
Cited in Sliding Patio Doors vs Bifolds.
- supplier figure RN-X8D3NG cited
Vufold
Vufold's product page for its Supreme 3.0 m by 2.1 m two-door aluminium sliding patio door set, showing its supply-only starting price.
Cited in Sliding Patio Doors vs Bifolds.
- supplier figure RN-JFQNAH cited
Wickes
the retail price Wickes publishes for Spacepro Sliding Wardrobe Door White Framed Mirror, which is the supply figure the cost book records for this item
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Wickes Building Supplies Ltd
the retail price Wickes Building Supplies Ltd publishes for Marshalls Driveline Priora Brindle Block Paving 200 x 100 x 60mm Pack of 404, which is the supply figure the cost book records for this item
Cited in Block Paving: Cost & Patterns, Driveway Cost & Materials: Block Paving, Resin & Gravel, Resin Bound Driveways: Cost & Pros/Cons.
- supplier figure RN-IE2QPK cited
Yale (ASSA ABLOY)
Yale's UK support page for euro cylinders. It explains measuring from the middle of the lock, with an example of internal 40 mm and external 50 mm, internal size stated first.
Cited in How to Change Upvc Door Lock.
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World Health Organization Regional Office for Europe
Published 15 October 2009, ISBN 9789289041737, the health-based benchmark for night-time noise that a soundproofing or acoustic glazing note can cite for what level of quiet is worth achieving. Using Lnight,outside as defined in the Environmental Noise Directive 2002/49/EC, it sets an Lnight,outside of 40 dB as the target of the night noise guideline to protect the public including the most vulnerable groups, named as children, the chronically ill and the elderly. It recommends an Lnight,outside of 55 dB as an interim target for countries that cannot achieve the guideline in the short term and adopt a stepwise approach. The guidelines were agreed by a working group of experts with industry, government and non-governmental stakeholders in December 2006, and extend and update the WHO Guidelines for community noise of 1999.
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Cadw, Welsh Government
WALES, and it imposes a documentary requirement England does not. A heritage impact statement MUST be submitted with every Welsh listed building consent application alongside detailed plans. Consent is administered by local planning authorities and may be needed for relatively minor work such as replacing an external door, painting or repainting the exterior or interior, or even cleaning. Replacement of traditional windows with UPVC will not normally be acceptable. Routine or like-for-like repairs do not normally need consent, but the criteria are exacting, and demolition always needs consent. Where the authority is minded to grant consent Cadw is normally notified and assesses whether the authority had proper regard to preservation, rather than the merits. The framework is Managing Change to Listed Buildings in Wales, which supplements Planning Policy Wales and Technical Advice Note 24: The Historic Environment, alongside Cadw's Conservation Principles.
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Department for Business and Trade
Published 31 March 2026, last updated 21 August 2026, and applying to England, Scotland and Wales. States that the UK continues to recognise the CE marking alongside or in place of the UKCA marking for the Great Britain market under the Product Safety and Metrology (Amendment) Regulations 2024, so a CE marked product remains lawful to place on the GB market and manufacturers may choose either route. Sets out the UKCA and CE regimes spanning over 20 product types, and the duties of each economic operator: the manufacturer designs and marks the product, applies identification details (name, trade name or trademark and postal address) and retains the technical documentation. Northern Ireland uses CE or CE and UKNI marking instead, and the UKCA marking does not apply in Guernsey, Jersey, the Isle of Man or the British Overseas Territories.
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Department of Finance (Northern Ireland)
The Northern Ireland index of technical booklets, which take the place of England's Approved Documents under the Building Regulations (Northern Ireland) 2012. Current editions: B materials and workmanship (July 2013), C site preparation and resistance to contaminants and moisture (October 2012), D structure (October 2012), E fire safety (October 2012), F1 conservation of fuel and power in dwellings and F2 in other buildings (both June 2022), G resistance to the passage of sound (October 2012), H stairs, ramps, guarding and protection from impact (October 2012), J solid waste (October 2012), K ventilation (October 2012), L combustion appliances and fuel storage (October 2012), M physical infrastructure for high-speed communications networks (January 2017), N drainage (October 2012), P sanitary appliances, unvented hot water storage and reducing the risk of scalding (October 2012), R access to and use of buildings (October 2012) and V glazing (October 2012). Note for any electrical note: there is no Northern Ireland technical booklet covering electrical safety, so there is no Part P equivalent and no electrical competent person self-certification regime there. Ventilation is Booklet K, drainage Booklet N and glazing Booklet V, not F, H and K as in England.
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Department of Finance (Northern Ireland)
NORTHERN IRELAND, giving a fourth set of U-values distinct from England, Wales and Scotland. Table 2.2 sets limiting area-weighted average U-values in W/m2.K with a maximum permitted at any point in brackets: wall 0.18 (0.60), floor 0.18 (0.60), roof 0.16 (0.30), party wall 0.00 (0.60), and windows, roof windows, glazed rooflights, curtain walling and pedestrian doors 1.40 (3.00). Where the space heating source is underfloor heating the maximum floor U-value tightens to 0.15. Compare Wales at 0.13 for roofs and Scotland at 0.12, against NI's 0.16. Paragraph 2.43 limits the extent of external doors and glazed openings in a dwelling to no more than 25 per cent of the dwelling's floor area, and the limiting air permeability is 10 m3 per hour per square metre at 50 Pa, looser than the Welsh 8.0. U-values are calculated to BRE Report BR 443. A swimming pool basin must achieve not more than 0.25.
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Health and Safety Executive
The HSE leaflet a decorating or period-property note should cite on lead paint. Names the highest-risk activities as blast removal and burning of old lead paint, stripping old lead paint from doors and windows, hot cutting in demolition and dismantling, some painting of buildings, and soldering. Corrects a common misconception: lead is not absorbed through the skin, except as lead alkyls and lead naphthenate, so the routes of entry are breathing in lead dust, fume or vapour and swallowing lead by eating, drinking, smoking or nail-biting without washing hands and face first. Absorbed lead circulates in the blood and is stored mainly in the bones, where it can remain for years without symptoms. Early effects are headaches, tiredness, irritability, constipation, nausea, stomach pains, anaemia and weight loss; continued uncontrolled exposure can cause kidney damage, nerve and brain damage and infertility. Flags that an unborn child is at particular risk, especially in the early weeks before a pregnancy is known. Where exposure is significant as defined in law, the employer must supply protective clothing, launder it, measure airborne lead, supply respiratory protective equipment if the occupational exposure limit cannot be met, and arrange blood-lead medical surveillance.
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Historic Environment Scotland
SCOTLAND, and it contradicts England directly on one point: conservation area consent still exists in Scotland for the demolition of unlisted buildings, whereas England abolished it in 2013 and folded relevant demolition into planning permission. As at March 2026 Scotland had more than 46,500 listed building records and more than 600 conservation areas. Listed building consent must be applied for from the planning authority before any change that may affect the character of the property, and is almost certainly needed for an extension, structural alterations, partial or total demolition, internal alterations affecting character, and changing windows and doors; cleaning stonework, changing external paint colour and new signage may also need permission. The owner is responsible for repair and maintenance. Planning authorities may hold a character appraisal explaining a conservation area's designation. HES and the Scottish Government Building Standards Division jointly publish the Guide to Conversion of Traditional Buildings to reconcile building standards with conservation.
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Historic Environment Scotland
SCOTLAND. Listed buildings are designated by Historic Environment Scotland under the Planning (Listed Buildings and Conservation Areas) (Scotland) Act 1997, not England's 1990 Act, and the first statutory listing in Scotland dates to 1957. There are around 47,000 listed buildings in Scotland, graded in three categories A, B and C by relative importance according to period, style or building type; the categories are advisory and affect how the building is managed in the planning system. Scotland's grading letters differ from England's Grade I, II* and II. Unless the statutory address explicitly says otherwise, a listing always covers the interior as well as the exterior, extensions and any attached structures, and unattached structures within the curtilage are also listed. Each building has an online Listed Building Record whose Statutory Address is the legal part of the listing. Listed Building Consent may be required for change, and designation decisions follow the HES Designation Policy and Selection Guidance.
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Ministry of Housing, Communities and Local Government
The 8 page document that sets out what a competent person scheme operator must satisfy, and it is what connects UKAS accreditation to the schemes a homeowner meets. Records that schemes are authorised under paragraph 4A of Schedule 1 to the Building Act 1984 and named in Schedule 3 to the Building Regulations 2010 as amended, and that in all cases demonstration must be sufficient to meet BS EN ISO/IEC 17065:2012, the product certification body standard. Condition 1 requires the scheme operator to achieve and maintain UKAS accreditation to BS EN ISO/IEC 17065:2012, within one year of authorisation for an extension to an existing scheme or within two years for a new scheme operator, with a UKAS pre-assessment submitted with the application. Condition 3 requires assessors and inspectors to be competent at least to the equivalent level in the relevant sector Minimum Technical Competence assessment procedure. Condition 4 requires a transparent fee structure, self-financing within not later than five years of authorisation, and use of registrants' registration and notification fees only for the benefit of registrants or the sector. Condition 5 requires documented management of conflicts of interest, noting the risk where a scheme is owned by a larger commercial, trade or professional body. In force for any UKAS assessment begun on or after 1 April 2016.
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Ministry of Housing, Communities and Local Government
The landing page for Approved Document L, Conservation of fuel and power. Volume 1: Dwellings, 2021 edition incorporating 2023 amendments, took effect 15 June 2022, with transitional cover where a building notice or initial notice was given or full plans deposited before 15 June 2022 and the work started before 15 June 2023. A 2026 edition, retitled Approved Document L: Energy and greenhouse gas emissions, Volume 1: Dwellings, is published on the same page alongside Volume 2 for buildings other than dwellings. Volume 1 was last updated 2 February 2023 and the 2023 amendment removed the primary energy factor as a performance standard for district heat networks and community heating.
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Ministry of Housing, Communities and Local Government
The list of test standards common across product families that UK approved bodies use when assessing construction products, published 27 January 2021 and last updated 21 May 2025, in force from 1 January 2021. Names the specific test methods behind fire performance claims a product data sheet will quote, so a note can verify what a rating actually measures: TS 1187 external fire exposure to roofs; EN ISO 1182 non-combustibility test; EN ISO 1716 gross heat of combustion or calorific value; EN 13823 the single burning item test for building products excluding floorings; EN ISO 11925-2 ignitability under direct flame impingement, the single-flame source test; EN ISO 9239-1 burning behaviour of floorings using a radiant heat source; EN 1365-3 and EN 1365-4 fire resistance of loadbearing beams and columns; EN 1634-1 and EN 1634-3 fire resistance and smoke control for door and shutter assemblies and openable windows; and the EN and ENV 13381 series for applied protection to composite, hollow steel, timber and steel structural members. The latest versions of the standards themselves are on the BSI website.
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Ministry of Housing, Communities and Local Government
The stable gov.uk landing page for Approved Document O, Overheating, 2021 edition, in force for England. It carries the free-area requirements a note would cite from Section 1: for cross-ventilated buildings the total minimum free area is the greater of 6% of floor area or 70% of glazing area in a high risk location, and the greater of 9% of floor area or 55% of glazing area in a moderate risk location (Table 1.3); without cross-ventilation it is the greater of 10% of floor area or 95% of glazing area (high risk) and 12% or 80% (moderate) (Table 1.4). Bedroom minimum free area is 13% of the room floor area in high risk locations and 4% in moderate. In high risk locations, glazing facing between north-east and north-west via south also needs shading by external shutters with ventilation, glazing with a maximum g-value of 0.4 and minimum light transmittance of 0.7, or overhangs with a 50 degree altitude cut-off on due south facades only; internal blinds, curtains and tree foliage may not be counted (paragraphs 2.8 and 2.9).
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Ministry of Housing, Communities and Local Government
The 2015 edition of Approved Document Q, published 5 March 2015 and last updated 22 November 2024 when frequently asked questions were added. Requirement Q1 (unauthorised access) requires reasonable provision to resist unauthorised access to any new dwelling and to any part of a building from which access can be gained to a flat within it. It is the only Approved Document about security, it bites only on new dwellings (including dwellings formed by a material change of use), and it sets out that doors and windows must be both sufficiently robust and fitted with appropriate hardware, tested to a recognised security standard. Useful for establishing that Part Q does not apply to a straight window replacement in an existing house.
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Ministry of Housing, Communities and Local Government and Office for Product Safety and Standards
The official list that decides which British and European standards a construction product's declaration of performance must be assessed against, first published 18 December 2020 and last updated 26 September 2025, applying to England, Scotland and Wales. Explains that designated standards support Regulation (EU) No. 305/2011 as amended from time to time, and that together with the horizontal standards on assessment methods they create the common technical language UK approved bodies use when carrying out assessments. Published as a notice of publication dated 26 September 2025, a 51 page PDF, superseding the notice of 1 January 2021 of 53 pages, alongside a consolidated list in ODS format at version 2. This is the reference that turns the standard number cited in a declaration of performance into a check that the right standard was used. A companion page covers horizontal test specifications for construction products.
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Scottish Government (gov.scot)
The in-force Scottish handbook, 13.6 MB PDF, applying from 6 April 2026. Figures a note on Scotland needs: Standard 4.6 requires a dwelling to have at least 4 thirteen-amp socket outlets in each apartment, 6 in the kitchen of which at least 3 above worktop level in addition to any for floor standing or built-in appliances, and a further 4 anywhere in the dwelling including at least 1 in each circulation area per storey, with no equivalent requirement in England. Clause 4.6.1 requires at least one lighting point in every circulation space, kitchen, bathroom, toilet and any space of 2 m2 or more; clause 4.6.2 sets 100 lux on stair flights and landings and 50 lux elsewhere in common circulation areas. Table 3.11 sets background ventilator equivalent areas of 12,000 mm2 per apartment and 10,000 mm2 for a kitchen, utility, toilet, bathroom or shower room, doubled where ducted, with part of the ventilator at least 1.75 m above floor level. Table 3.12 sets intermittent extract rates of 30 l/s over a hob, 60 l/s elsewhere in a kitchen, 30 l/s utility, 15 l/s bathroom or shower, 6 l/s WC, with fan and background ventilator at least 0.5 m apart. Table 6.2 sets maximum U-values of 0.17 wall, 0.15 floor, 0.12 roof, 1.4 windows, roof windows and doors, 2.1 rooflights, with a Window Energy Rating or Doorset Energy Rating of B or better as an alternative for units in an existing building; for 1 or 2 matching replacement windows the frame may be disregarded if the centre pane U-value is 1.2 W/m2K or less, secondary glazing should reach about 3.5 W/m2K, and total glazed area should not exceed 25 per cent of dwelling floor area. Clause 4.8.2 requires glazing to BS 6262-4:2018 within 800 mm of floor level, in a door leaf, or within 300 mm of a door leaf and within 1.5 m of floor level, with manifestation between 850 mm and 1.0 m and between 1.4 m and 1.6 m above floor level. Clause 4.8.3 requires any window or rooflight more than 4 m above adjacent ground or floor to be cleanable safely from inside per Clause 8 of BS 8213-1:2004, from a loadbearing surface, or from a mounted access system, sets safe reach limits of 610 mm downward and an 850 mm radius arc from a point not more than 1.3 m above floor level, and bars ladder access to glazing more than 9 m above the ladder's footing.
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Scottish Government (gov.scot)
Scotland's equivalent of the Approved Documents, and the reason a note that quotes only English rules is wrong for a fifth of the UK. This edition is in force from 6 April 2026 and applies to building warrants submitted on or after that date and to work not requiring a warrant commenced from that date. It gives guidance on achieving the standards set in the Building (Scotland) Regulations 2004, arranged in sections rather than parts: section 3 environment (ventilation, drainage, condensation), section 4 safety (electrical safety and installations, glazing and danger from accidents, including clause 4.13 which invokes PAS 24 for security), section 6 energy (U-values for windows and doors) and section 7 sustainability. Scotland uses a building warrant and a completion certificate rather than a building notice, and has no Part P competent person scheme equivalent, so electrical work is covered by the warrant system instead.
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Scottish Government (gov.scot)
SCOTLAND, and the numbering has no England equivalent: Scotland puts escape under Standard 2.9, not Approved Document B. Clause 2.9.4 requires an escape window in every apartment on an upper storey not more than 4.5 metres above the adjacent ground, and in every inner room at that height, unless there is an alternative route of escape. The escape window must have an unobstructed openable area of at least 0.33 square metres and be at least 450 mm high and 450 mm wide, with the bottom of the openable area not more than 1100 mm above the floor; the route through may be at an angle. Above 4.5 metres an escape window is not accepted and clause 2.9.5 requires every apartment to have direct access to a protected enclosure with self-closing short fire resistance duration fire doors leading to an exit door. Above 7.5 metres clause 2.9.6 requires an alternative exit. Text verified identical in the April 2026 PDF handbook.
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The National Archives (legislation.gov.uk)
Sets out exactly what a declaration of performance must contain, which is what to look for when checking a product claim. Article 6(2) requires the product-type reference, the system or systems of assessment and verification of constancy of performance from Annex V, the reference number and date of issue of the designated standard or UK Technical Assessment used for each essential characteristic, and any Specific Technical Documentation reference. Article 6(3) requires the intended use or uses, the list of essential characteristics, the performance of at least one essential characteristic, performance stated by level, class or description, and crucially that any listed essential characteristic for which no performance is declared must carry the letters NPD, meaning No Performance Determined. Article 6(4) requires the declaration to follow the model in Annex III.
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The National Archives (legislation.gov.uk)
The instrument that made the 2021 changes real, so a note can date them exactly. Regulation 1 sets citation and commencement on 15 June 2022, extending to England and Wales but applying to buildings and building work in England. Regulation 11 amends Schedule 1: it adds "to a reasonable standard" to entry L1(b)(i), inserts new requirement L2 on on-site generation of electricity (systems must be appropriately sized, have effective controls and be commissioned to produce the maximum electricity reasonable in the circumstances), and inserts a whole new PART O OVERHEATING with requirement O1, reproduced in full and carrying NO limits on application. Regulation 4 inserts regulation 4(4) and 4(5), a rule renovation guides almost never mention: where Part L imposes a requirement on the work, then on completion the whole building must comply with Part F or be no more unsatisfactory in relation to Part F than before the work began, so a Part L job such as new glazing or wall insulation drags a whole-house ventilation duty with it. Regulation 8 inserts regulations 40A and 40B, requiring the person carrying out the work to give the owner information about an on-site electricity generation system, and about the Part O overheating provision, no later than five days after completion. Regulation 17 is the transitional provision: the amendments do not apply where a building notice or initial notice was given, or full plans deposited, before 15 June 2022, provided the work started before 15 June 2023.
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Welsh Government
The Welsh Government circular announcing the 2026 editions. Approved Document L (Conservation of fuel and power and the minimisation of greenhouse gas emissions) Volumes 1 and 2 and Approved Document F (Ventilation) Volume 1 were published on 7 April 2026 and come into force on 4 March 2027. The transitional arrangements are precise and matter to anyone starting work near that date: the new documents do not apply to building work commenced before 4 March 2027 in accordance with any relevant notification provision, nor where notification was given before that date and the work commences before the period ending on 3 March 2028. The circular is informational and states expressly that it does not give advice on the technical requirements, which are in the Approved Documents themselves.
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Welsh Government (gov.wales)
The Welsh Approved Document L Volume 1, in force until 3 March 2027, and the source for Welsh window figures, which are not identical to England's. Table 10.1 sets, for new and replacement windows and roof windows, a maximum U-value of 1.4 W/(m2K) or WER Band B, with an alternative for replacements of 1.2 W/(m2K) centre pane or low-E secondary glazing, and a threshold U-value for retained windows of 3.3. Rooflights: 2.2 for new and replacement, threshold 3.8. Doors more than 60 per cent glazed: 1.4 or DSER Band C, alternative 1.2 centre pane, threshold 3.3. All other doors: 1.4 or DSER Band B, threshold 3.3. External fire doorsets as defined in Approved Document B Volume 1 may be 1.8. Transitional easements allowed timber windows at 1.6 or WER Band C and timber doors at 1.8 or DSER Band E only where a building notice, initial notice or full plans were given before 23 November 2023. Paragraph 11.35 requires an existing window or door worse than the column (c) threshold to be replaced to column (a); paragraph 11.37 states that windows and doors mean the whole unit including the frame, so replacing just the glazing or the door leaf while retaining the existing frame is not building work and does not have to meet the energy efficiency requirements, though upgrading as close as practicable is sensible; paragraph 11.38 caps the total area of windows and doors at 25 per cent of total floor area where one is enlarged or created.
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Welsh Government (gov.wales)
The Welsh Government landing page that shows which edition of Approved Document L applies in Wales and when. Two editions of Volume 1 (dwellings) sit side by side: the current edition in force until 3 March 2027 at /sites/default/files/publications/2024-05/building-regulations-approved-document-l-vol-1.pdf, and the 2026 edition in force from 4 March 2027 at /sites/default/files/publications/2026-04/building-regulations-approved-document-l-vol-1-2026.pdf. Note the date differs from England, where the 2026 edition of Approved Document L takes effect on 24 March 2027, so a note giving a single UK-wide changeover date is wrong for Wales by three weeks.
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Cambridgeshire Fire and Rescue Service
Cambridgeshire Fire and Rescue Service's five-step check of a fire door: certification label, gaps around the door, intumescent seals, hinges, and whether it closes fully by itself.
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Royal Borough of Greenwich, Housing and Safer Communities
United Living pricing schedules, contract SPS-2686, Doors schedule ref D0052 and Replace Bespoke SoR ref D114, a council publishing its own schedule. It binds in that district only, so it is cited as evidence of local charges and never as the authority for a national rule
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British Fenestration Rating Council (BFRC)
BFRC's own explanation of how a window energy rating is produced and policed. The rating scale runs from A++ at the best to E at the worst, and the rating is an energy balance: positive contributions from solar gain minus the negative contributions of thermal heat loss and air leakage, so a rating is not the same thing as a U-value. A certified product carries an official sticker inside the frame showing the rating letter, the certified company name and the BFRC membership number, and the licence can be checked as active on the BFRC website. BFRC describes the scheme as a verified method of achieving compliance with building regulations, and separately certifies U-values for use by SAP assessors and for UKCA marking. This is the page to cite when a note has to explain that an A-rated window and a 1.4 W/m2K window are two different claims.
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BSI
Part 1 of the insulating glass unit series, covering generalities, system description, rules for substitution, tolerances and visual quality. It defines insulating glass as two or more glass panes spaced apart and sealed with a sealant to behave as a single unit, and names the intended uses: windows, doors, curtain walling, bonded glazing for doors, windows and curtain walling, roofs and partitions. Meeting the standard indicates that a unit fulfils the needs of its intended use, and the conformity evaluation is what assures that visual, energetic, acoustic and safety parameters do not change significantly over time. BS EN 1279-1:2018 supersedes and withdraws BS EN 1279-1:2004 with technical changes. This is the reference for what counts as an acceptable visual defect in a new sealed unit, which is the question behind most double glazing disputes.
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BSI
part 2 of the European standard series on insulating glass units, current and published 31 July 2018, which describes the test method for determining the moisture penetration index of a sealed unit and specifies the limit values it must meet. It is the standard behind the failure that shows as condensation inside a double glazed unit, which is a failure of the unit edge seal rather than of the external glazing gasket
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BSI
The product standard for the sealed double glazed unit itself, published 31 July 2018 and current but under review. It sets requirements for insulating glass units used in buildings, covering thermal performance, energy efficiency and sound control, and excludes artistic-use-only units that do not require CE marking. The 2018 revision aligns it with EU Construction Product Regulation 305/2011, adding requirements for bonded glazing systems, solar factor declarations, durability assessment and mechanical resistance in the Declaration of Performance. Its sibling parts define the rest of the family: BS EN 1279-1:2018 on generalities, system description, rules for substitution, tolerances and visual quality, BS EN 1279-2 on the long-term moisture penetration test, BS EN 1279-3 on gas leakage rate and gas concentration tolerances, and BS EN 1279-4 on the physical attributes of edge seal components. This is the standard behind a misted or blown unit failing, because the edge seal is what has given way.