References

Insulation & Membranes

273 sources in the library on insulation & membranes, 40 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 1 of 7.

  1. very strong RN-5CL50F cited

    Building Control Northern Ireland

    The index of Northern Ireland's Technical Booklets, the devolved equivalent of England's Approved Documents, and the place to check which NI booklet answers a question. The booklets run B materials and workmanship, C site preparation and resistance to contaminants and moisture, D structure, E fire safety, F1 conservation of fuel and power in dwellings (2022 edition) and F2 for buildings other than dwellings, G sound, H stairs ramps and guarding, J solid waste, K ventilation, L combustion appliances and fuel storage, M physical infrastructure for high speed electronic communications networks, N drainage, P sanitary appliances and unvented hot water storage, R access to and use of buildings, and V glazing. Amendment booklets AMD7 (amends B, C and E), AMD8 (amends R) and AMD9 (amends E and R) carry the live changes, so the base 2012 booklets must be read with them.

    Cited in Spiral Staircases: Sizes, Building Regs & Cost.

  2. very strong RN-AS0G0P cited

    Department for Energy Security and Net Zero

    Published 21 January 2026 and last updated 18 March 2026. It commits £15 billion of public investment over this Parliament, 2025/26 to 2029/30, to upgrade up to 5 million homes by 2030, targeting over 450,000 heat pump installations a year by 2030 and solar panels on up to 3 million additional homes. The Boiler Upgrade Scheme gets £2.7 billion to 2030, keeping the £7,500 grant for hydronic heat pumps, adding new £2,500 grants for air-to-air heat pumps and heat batteries used for central heating, and £5,000 for biomass boilers in rural areas. A Warm Homes Fund provides a £5 billion financial transactions facility including £1.7 billion for low and zero-interest consumer loans, rolling out in phases from 2026, and the Warm Homes Social Housing Fund and Local Grant merge into a single low-income scheme from 2027/28. Private rented sector properties must meet EPC Band C across two metrics by October 2030, subject to a £10,000 spending cap, and an EPC C standard is introduced for the social rented sector for the first time. Future Homes Standard regulations were to be laid in Q1 2026.

    Cited in Combi vs System vs Regular Boilers.

  3. very strong RN-DNUSE8 cited

    Department of Finance (Northern Ireland)

    Northern Ireland's equivalent of Approved Document L Volume 1. This edition came into effect on 30 June 2022 and gives guidance on regulations 39 to 47 of the Building Regulations (Northern Ireland) 2012, which set the requirements for conservation of fuel and power in dwellings, including the limiting U-values a replacement window or door must meet in Northern Ireland. It replaced the 2012 version, and the Department publishes an awareness briefing and FAQ setting out the differences. The full text is at https://www.finance-ni.gov.uk/sites/default/files/publications/dfp/TB%20Part%20F1%202022_On-Line%20Publication.pdf. Cite this rather than Approved Document L whenever a note gives a window U-value for a reader in Northern Ireland.

    Cited in Insulation: The Complete Guide.

  4. very strong RN-U1PW3G cited

    GOV.UK

    The England-only successor to the Home Upgrade Grant, delivered by local councils. Eligibility: household income of £36,000 a year or less (with postcode and benefit-based exceptions), privately owned home, EPC rating D to G. Funds wall, loft and underfloor insulation, air source heat pumps, smart controls and solar panels, with the council organising and paying for the work. Explicitly 'only available in England'. Use this whenever a note says HUG closed and a successor is awaited: it is live and taking applications.

    Cited in LPG Conversion Cost: 2026 UK Price Guide.

  5. very strong RN-1HRJJ7 cited

    HM Revenue & Customs

    Section 2.1 sets a zero rate of VAT on the installation of energy-saving materials in residential accommodation from 1 May 2023 to 31 March 2027, after which the rate reverts to the 5% reduced rate; section 2.22 extended it to buildings used solely for relevant charitable purposes from 1 February 2024. Section 2.7 lists the qualifying materials: central heating and hot water controls, draught stripping, insulation to walls, floors, ceilings, roofs, lofts and pipes, solar panels, wind turbines, water turbines, ground source heat pumps, air source heat pumps, micro combined heat and power units and wood-fuelled boilers, with water source heat pumps, batteries for energy storage and smart diverters added on 1 February 2024. Section 2.3 is the critical rule for a renovation note: relief applies to an installation service, or materials supplied and installed together, but materials bought without installation stay standard-rated at 20%.

    Cited in Builders' Merchants: The Complete UK Guide (2026), Cost of a New Bathroom (Full Breakdown), Hot Water Options for Your Home, How Much Does a New Roof Cost in 2026? (UK) and 4 more.

  6. very strong RN-NPO8FJ cited

    Ministry of Housing, Communities and Local Government

    The statutory figures behind a damp diagnosis, and the numbers to quote when a note explains why ground levels or a bridged damp proof course cause rising damp. Paragraph 5.2 requires that in an external wall the damp-proof course should be at least 150mm above the level of the adjoining ground (Diagram 8) unless part of the building protects the wall, and that in an external cavity wall the cavity should be taken down at least 225mm below the level of the lowest damp-proof course, or a damp-proof tray provided (Diagram 9a). For suspended timber ground floors it requires a ventilated air space of at least 75mm from the ground covering to the underside of any wall-plates and at least 150mm to the underside of the suspended timber floor or insulation, with ventilation openings on two opposing external walls of not less than 1,500mm2 per metre run of external wall or 500mm2 per square metre of floor area, whichever is greater; for suspended concrete floors the clear ventilated space is at least 150mm with the same opening sizes. Section 2.39 onwards covers radon, referring to BRE Report BR 211 for protective measures. The 2013 edition was published on 3 September 2013 with changes in effect from 1 October 2013.

    Cited in Barge Boards, Fascias & Soffits: Cost & Replacement, Breathable Membranes for Roofs & Walls, Brick Slips & Brick Cladding Systems, Build Basement Cost: 2026 UK Price Guide and 35 more.

  7. very strong RN-QD1SFF cited

    Ministry of Housing, Communities and Local Government

    Table 1.1 sets minimum intermittent extract rates: kitchen with a cooker hood extracting outside 30 l/s, kitchen without one 60 l/s, utility room 30 l/s, bathroom 15 l/s, sanitary accommodation 6 l/s. Extract terminals and fans other than cooker hoods should be as high as practicable and no more than 400mm below the ceiling; a cooker hood should sit between 650mm and 750mm above the hob if the manufacturer gives no figure. Table 1.7 requires background ventilators of at least 8000mm2 equivalent area in habitable rooms and kitchens for a dwelling, 10,000mm2 for a single-storey dwelling. Background ventilators should be at least 1700mm above floor level and at least 500mm from a fan in the same room. On replacement windows, paragraph 3.14 says new windows must carry background ventilators no smaller than the originals, and paragraph 3.15 gives the fallback minimums where the old size is unknown: 8000mm2 habitable rooms, 8000mm2 kitchen, 4000mm2 bathroom. Paragraph 3.32 confirms that replacing an extractor fan or cooker hood on existing cabling is not notifiable.

    Cited in Adding an Ensuite: Cost, Layout & Plumbing, Annexe & Granny Flat: Cost, Planning & Rules, Basement & Cellar Conversions: Cost, Bathroom Remodel Cost: 2026 UK Price Guide and 44 more.

  8. very strong RN-L0FCJX cited

    Ministry of Housing, Communities and Local Government

    The in-force U-value tables a DIY insulation or door note must quote, with the exact numbers. Table 4.2, limiting U-values for new fabric elements in existing dwellings, sets roof 0.15, wall 0.18, floor 0.18, swimming pool basin 0.25, window 1.4 or Window Energy Rating Band B minimum, rooflight 2.2, doors with more than 60 per cent of the internal face glazed 1.4 or Doorset Energy Rating Band C minimum, and other doors 1.4 or Doorset Energy Rating Band B minimum. Table 4.3, for existing elements, gives a roof threshold of 0.35 and an improved value of 0.16, which is the figure a loft insulation note needs: paragraph 4.12 says a retained element whose U-value is higher than the column (a) threshold, for example through a loft or garage conversion, should be upgraded to the column (b) value. Paragraph 4.13 allows a lesser upgrade only where the improved value is not technically or functionally feasible or would not achieve a simple payback of 15 years or less. Paragraph 4.8 requires a replacement element to be no worse than the one it replaces as well as meeting Table 4.2. Paragraph 4.10 gives the heritage exception: where character must be maintained, a centre pane U-value of no more than 1.2 or low-emissivity secondary glazing. Note 9 records that the timber window concession of 1.6 or Band C ended on 14 June 2023. The 2021 edition came into force on 15 June 2022; a 2026 edition exists at https://assets.publishing.service.gov.uk/media/69c122a6cfa346b9d4704a55/ADL1_2026.pdf.

    Cited in Adding an Ensuite: Cost, Layout & Plumbing, Adding Porch, All You Need To Know About Double Glazing Repairs, Annexe & Granny Flat: Cost, Planning & Rules and 136 more.

  9. very strong RN-X4J5YY cited

    Ministry of Housing, Communities and Local Government

    The 2026 edition takes effect on 24 March 2027 for work not connected with higher-risk building work, and 24 September 2027 where it is, with transitional arrangements in Circular Letter 01/2026. Table 3.1 sets limiting U-values for new dwellings: all roof types 0.16, wall 0.26, floor 0.18, window 1.6, rooflight 2.2, doors 1.6 W per square metre per kelvin, with air permeability 8.0 cubic metres per hour per square metre at 50Pa. Table 3.2 covers new elements in existing dwellings, that is extensions and loft conversions: roof 0.15, wall 0.18, floor 0.18, window 1.4 or Window Energy Rating Band B, rooflight 2.2. Table 3.3 covers upgrading existing elements: a roof with a U-value worse than the 0.35 threshold must be improved to 0.16, and note 2 confirms that for dormer windows the roof figure covers the roof parts and the wall figure the cheeks, while note 3 allows a higher U-value where the standard would limit head room provided the insulation plus air gap is at least the depth of the rafters.

    Cited in Insulation: The Complete Guide.

  10. very strong RN-R7QZ7M cited

    Ministry of Housing, Communities and Local Government

    Supports Part O of Schedule 1 to the Building Regulations 2010 (requirement O1 and regulation 40B); the 2021 edition took effect on 15 June 2022 in England, with transitional relief for work notified before that date and started before 15 June 2023. Critically, paragraph 0.3 limits the guidance to NEW residential buildings only (dwellings, residential institutional and residential other, plus shared communal rooms, common spaces and live/work units), and paragraph 0.7 applies it only to the residential parts of mixed-use buildings. Compliance is by the simplified method (Section 1) or dynamic thermal modelling to CIBSE TM59 (Section 2); the simplified method splits England into a high risk location (urban and some suburban London listed in Appendix C, with guidance for parts of central Manchester) and a moderate risk location (the rest of England). Table 1.1 (cross-ventilated) caps glazing as a percentage of floor area at north 15 high risk / 18 moderate, east 18/18, south 15/15, west 18/11, with the most glazed room capped at north 37/37, east 37/37, south 22/30, west 37/22. Table 1.2 (no cross-ventilation) caps glazing at north 15/18, east 11/18, south 11/15, west 11/11, most glazed room north 26/26, east 18/26, south 11/15, west 18/11.

    Cited in Glazed Extensions: The Complete UK Guide, Glazing Explained: U-values, Low-E, Argon & Spacers, Rooflights & Skylights: Materials & Types.

  11. very strong RN-ISI2YI cited

    Ministry of Housing, Communities and Local Government

    2024 government hygrothermal modelling assessment of sprayed foam on domestic timber roofs, and an unusually quotable secondary source for BS 5250:2021's prescriptive roof guidance. Risks are low only where an OPEN CELL, moisture permeable insulant is used with an air and vapour control layer on the warm side and a space left between insulation and underlay, ventilated from the eaves where a high resistance underlay is used. For a WARM pitched roof with a high resistance underlay such as bitumen felt: each ventilated void should be at least 25 mm deep, ventilated at high and low level, plus a 15 mm allowance for underlay drape, giving 25 + 15 = 40 mm. For a low resistance underlay, option 1 is an AVCL plus an unventilated counter batten air gap for air permeable coverings; option 2, where an AVCL is impracticable, follows the HR guidance. It also states plainly that official moisture guidance is Approved Document C, that AD C was last fully revised in 2004 with 2010 and 2013 amendments, and that AD C REFERENCES THE 2002 EDITION OF BS 5250, not the current 2021 edition. It names BS EN ISO 13788:2012 (the Glaser method) as the calculation method referenced by the 2002 edition, and notes the Glaser method may underestimate risk because it cannot simulate heat and liquid transport, unlike BS EN 15026:2007.

    Cited in Internal Wall Insulation: Costs & Methods, Roof Tiles & Slates: Coverage, Fixings & Ventilation.

  12. very strong RN-2WZR3Y cited

    Ministry of Housing, Communities and Local Government

    The landing page for Approved Document F, Ventilation. Volume 1 covers dwellings and Volume 2 buildings other than dwellings; the current edition took effect 15 June 2022 and a 2026 edition is published on the same page. This is the document that sets background ventilation (trickle vent) equivalent areas and intermittent extract rates, and the reason replacement windows must not make existing ventilation worse. Volume 1 is a 859 KB PDF, Volume 2 is 662 KB.

    Cited in All You Need To Know About Double Glazing Repairs, Building Regulations Explained for Homeowners, How to Fit a Bathroom Suite.

  13. very strong RN-Y19S87 cited

    Office for Product Safety and Standards and Ministry of Housing, Communities and Local Government

    Names the Office for Product Safety and Standards as the UK regulator for construction products and most consumer goods, a role it took on in April 2021, funded by and acting on behalf of MHCLG. Confirms the enforced legislation is the Construction Products Regulations 2013 as amended by the Construction Products (Amendment) Regulations 2022, which gave OPSS its enforcement powers. Records that the Grenfell Tower Inquiry final report was published on 4 September 2024, the Government response on 26 February 2025 accepting all 58 recommendations, and a Construction Products Reform White Paper on 25 February 2026 proposing reform of testing, certification, product information and enforcement. OPSS carries out product testing, site inspections and technical documentation reviews, responded to over 100 non-compliance allegations in 2023, and publishes construction product safety alerts, reports and recalls.

    Cited in Builders' Merchants: The Complete UK Guide (2026).

  14. very strong RN-FPPUSL cited

    Ofgem

    ECO4 is the fourth phase of the Energy Company Obligation across Great Britain. It applies to measures installed from 1 April 2022 and runs until 31 December 2026 following a nine-month extension; ECO3 closed on 31 March 2022 and ECO4 came into force in July 2022. The scheme places a Home Heating Cost Reduction Obligation on medium and large energy suppliers to promote measures that improve the ability of low-income, fuel-poor and vulnerable households to heat their homes, funding insulation and heating upgrades for both homeowners and tenants. Ofgem also lists the Great British Insulation Scheme as a separate obligation on this page.

    Cited in Electric Heating Options Compared, Fan Assisted Radiators Cost: 2026 UK Price Guide, Insulation: The Complete Guide, Insulation Grants 2026: ECO4, GBIS & What You Can Get and 4 more.

  15. very strong RN-RDOIJR cited

    Ofgem

    The scheme, formerly known as ECO+, ran from April 2023 to 31 March 2026 and is now closed. It obliged medium and large energy suppliers to deliver measures reducing energy use in the least energy-efficient homes in Great Britain. Eligibility was homes with an EPC rating of D to G in Council Tax bands A to D in England, or A to E in Scotland and Wales, plus low-income and vulnerable households. Unlike ECO4, which funds whole-house packages, GBIS mostly delivered a single insulation measure per home. This is the page to cite when a note has to say a grant route has closed rather than leave a reader chasing it.

    Cited in Electric Heating Options Compared, Fan Assisted Radiators Cost: 2026 UK Price Guide, Home Energy Audit: DIY Steps, House Rendering Cost: Whole-House Render Prices (2026) and 9 more.

  16. very strong RN-QJIETI cited

    Scottish Government (gov.scot)

    Scotland's U-value backstops, which differ from England's Approved Document L and are the numbers to quote for a Scottish reader. Table 6.3 for new dwellings gives area-weighted average maximum U-values in W/m2K of wall 0.22, floor 0.18, roof 0.15, windows, doors and rooflights 1.6, and cavity separating wall 0.2, with individual element values of 0.70 for wall and floor, 0.35 for roof and 3.3 for windows, doors and rooflights. A cavity separating wall can be assigned 0.2 where the cavity has effective perimeter sealing around all exposed edges in line with the insulation layers of abutting elements, and 0.0 where the cavity is also fully filled with a material limiting air movement. Table 6.5 for extensions and conversions is two-column: where the existing dwelling's wall and roof U-values are poorer than 0.7 and 0.25 respectively, wall 0.17, floor 0.15, pitched roof with insulation between ceiling ties or collars 0.11, flat or pitched roof with insulation between rafters or integral 0.13 and windows, doors and rooflights 1.4; where those parameters do not apply the figures relax to 0.22, 0.18, 0.15, 0.18 and 1.6, with individual element values of 0.70, 0.70, 0.35, 0.35 and 3.3. Localised poorer areas such as a meter box must be compensated by the rest of the element and are important for condensation control, while repeating thermal bridges such as timber studs are not treated as individual elements because they are already in the BS EN ISO 6946 calculation.

    Cited in Insulation: The Complete Guide.

  17. very strong RN-Z3KFVU cited

    The National Archives (legislation.gov.uk)

    The regulation behind the combustible cladding ban. Regulation 7(2) requires materials in the external walls or specified attachments of a relevant building to achieve European Classification A2-s1, d0 or A1 for reaction to fire, and regulation 7(1A) prohibits relevant metal composite materials in external walls. Regulation 7(4) defines a relevant building as one with a storey at least 18 metres above ground level, excluding roof-top plant areas and storeys consisting only of plant rooms, containing one or more dwellings, an institution, or a room for residential purposes. Regulation 7(3) lists the exempt components: cavity trays between masonry leaves, parts of roofs connected to external walls, door frames and doors, electrical installations, fibre optic cables, insulation and waterproofing below ground or up to 300mm above it, intumescent and fire-stopping materials, membranes, seals, gaskets, fixings, sealants and backer rods, solar shading device components other than the primary shade element, thermal break materials used for Part L compliance, window frames and glass, and balcony floor layers classified A1fl or A2fl-s1 over an imperforate substrate.

    Cited in Cladding and Render: The Complete UK Guide (2026), External Wall Insulation (EWI) Systems & Finishes, House Cladding Cost: 2026 UK Price Guide, Kingspan & Celotex PIR Boards: Sizes & Cost and 1 more.

  18. very strong RN-1MN06H cited

    The National Archives (legislation.gov.uk), Northern Ireland Statutory Rules

    NORTHERN IRELAND, and the part letters mean different things from England, so quoting an England part letter into an NI note is a straight error. The parts are A interpretation and general, B materials and workmanship, C site preparation and resistance to contaminants and moisture, D structure, E fire safety, F conservation of fuel and power, G resistance to the passage of sound, H stairs, ramps, guarding and protection from impact, J solid waste, K ventilation, L combustion appliances and fuel storage systems, N drainage, P sanitary appliances, unvented hot water storage systems and reducing the risk of scalding, R access to and use of buildings, and V glazing. So NI Part D is England's Part A, NI Part E is England's Part B, NI Part F is England's Part L, NI Part K is England's Part F, NI Part L is England's Part J, NI Part N is England's Part H, NI Part P is England's Part G and emphatically NOT electrical safety, NI Part R is England's Part M, and NI Part V is glazing. There is NO part covering electrical safety anywhere in these regulations, so domestic electrical work in Northern Ireland is not notifiable building work as it is under England's and Wales's Part P. Regulation 41 imposes consequential improvements, regulation 42 change of energy status and regulation 43 renovation of thermal elements.

    Cited in Sockets & Light Switches: Types, Heights & Regs.

  19. very strong RN-03F4DZ cited

    The National Archives (legislation.gov.uk), UK Statutory Instrument 2022/603

    The amendment that tightened the England combustible cladding ban, made under sections 1 and Schedule 1 of the Building Act 1984 and in force on 1 December 2022, extending to England and Wales but expressly not applying to any building in Wales. It inserts the definitions that decide the ban's reach. Reaction to fire classification is fixed as BS EN 13501-1:2018 published by BSI in 2019. Relevant metal composite material means any panel or sheet no more than 10 mm thick comprised of layers, two or more of metal, alloy or metal compound, and one or more substantial layer of a material with a gross calorific value of more than 35 MJ/kg tested to BS EN ISO 1716:2018, with a substantial layer defined as at least 1 mm thick or at least 1 kg per square metre. Specified attachment means a balcony attached to an external wall, a solar shading device other than one attached at a height of no more than 4.5 metres above ground level, or a solar panel attached to an external wall. It also lowers the material change of use trigger in regulation 6(1)(c) from fifteen to eleven metres, and substitutes regulation 6(3) so that on a material change of use under regulation 5(k) the external wall and specified attachments must contain only Class A2-s1, d0 or A1 materials. Regulation 7(2) is substituted in the same terms.

    Cited in Cladding and Render: The Complete UK Guide (2026).

  20. very strong RN-KXCXCY cited

    Welsh Government (gov.wales)

    WALES. First published 3 April 2017, last updated 7 April 2026. Wales publishes its own Approved Document F, and the page carries the current volume 1 for dwellings (910 KB PDF) and volume 2 for buildings other than dwellings, plus replacement volumes that TAKE EFFECT ON 4 MARCH 2027, the same changeover date as the Welsh Approved Document L and distinct from England's 24 March 2027. Welsh Part F diverged from England's when England issued its 2021 edition alongside Part L and Part O, so extract rates and background ventilator provisions for a Welsh bathroom, kitchen or loft conversion should be taken from this document rather than from England's Approved Document F.

    Cited in Trickle Vents & Background Ventilation.

  21. very strong RN-NUL2UK cited

    Welsh Government (gov.wales)

    WALES. The Welsh Government publishes its own Approved Documents, and this collection page, last updated 19 June 2025, lists them with their current dates so the right edition can be cited: A structure 3 April 2017, B fire safety 19 June 2025, C site preparation and resistance to contaminants and moisture 3 April 2017, D toxic substances 3 April 2017, E resistance to the passage of sound 13 April 2022, F ventilation 7 April 2026, G sanitation, hot water safety and water efficiency 10 May 2023, H drainage and waste disposal 3 April 2017, J combustion appliances 6 January 2025, K protection from falling 19 March 2025, L conservation of fuel and power 7 April 2026, M access 20 March 2025, N glazing 5 April 2017, O overheating, P electrical safety, Q security and R volumes 1 and 2. Wales still has a live Approved Document N on glazing safety, opening and cleaning, which England withdrew in 2013 when its content moved into Part K, so an England-based note that says Part N no longer exists is wrong for Wales.

    Cited in Internal Doors: Types, Sizes & How to Choose.

  22. very strong RN-CY8PF5 cited

    Welsh Government (gov.wales)

    WALES. Loft insulation must meet the minimum energy efficiency values in the Welsh Approved Documents, and where that upgrade is not technically or functionally feasible the element must instead be upgraded to the best standard achievable within a simple payback of no greater than 15 years. Installing loft insulation as part of a roof renovation where MORE THAN 25 PER CENT OF THE ROOF is being renewed triggers the full Approved Document standard, the Welsh version of the renovation of a thermal element trigger. The guidance warns against blocking ventilation at the eaves. Read alongside Table 4.1 of the Welsh Approved Document L Volume 1, which sets 0.13 W/m2K for roofs in both new and existing dwellings.

    Cited in Insulation: The Complete Guide.

  23. strong RN-X4CJG1 cited

    BSI

    the withdrawn guide to assessing a cavity wall's suitability for filling, which Approved Document C still names

    Cited in Cavity Wall Insulation Materials Compared, Wall Insulation Materials: Cavity, Internal & External.

  24. strong RN-9A1H9G cited

    BSI

    The standard that produces the Euroclass letter, and the one regulation 7(2) of the Building Regulations names by title and ISBN when it requires external wall materials on a relevant building to be Class A2-s1, d0 or A1. Published 31 Jan 2019 and Current. Part 1 provides the reaction to fire classification procedure for all construction products, including products incorporated within building elements, with the sole exception of power, control and communication cables which are classified under EN 13501-6. Products are considered in relation to their end-use application, which is why an insulation board or cladding panel cannot carry a meaningful Euroclass in the abstract: the classification attaches to the product as used in a stated build-up. This is the reference for reading the suffixes as well as the letter, s for smoke production and d for flaming droplets.

    Cited in Cladding and Render: The Complete UK Guide (2026), PIR vs Mineral Wool Insulation Compared.

  25. strong RN-2T8K9A cited

    BSI

    the laboratory method for measuring the sound insulation of a building element, which is where a product's Rw comes from

    Cited in Acoustic Insulation for Floors & Walls.

  26. strong RN-VLMNAU cited

    BSI

    the standard the driving rain index behind the UK exposure map is calculated to, from hourly wind and rain data

    Cited in Cavity Wall Insulation Materials Compared.

  27. strong RN-24Q969 cited

    BSI

    the field method for measuring sound insulation in a finished building, which is what a Part E pre-completion test runs to

    Cited in Acoustic Insulation for Floors & Walls.

  28. strong RN-SI9E6S cited

    BSI

    the standard that rates airborne sound insulation into a single figure, which is where Rw and the C and Ctr spectrum adaptation terms come from

    Cited in Acoustic Insulation for Floors & Walls.

  29. strong RN-F2ZMFF cited

    BSI

    the standard that rates impact sound insulation into a single figure

    Cited in Acoustic Insulation for Floors & Walls.

  30. strong RN-DCE677 cited

    BSI

    the combined retrofit specification that publicly funded energy efficiency work has to be installed under

    Cited in Cavity Wall Insulation Materials Compared, Insulation Grants 2026: ECO4, GBIS & What You Can Get, Loft & Roll Insulation: Types, Depth & U-values, Rockwool vs Other Mineral Wool: Which to Use and 2 more.

  31. strong RN-L1P8GV cited

    BSI (British Standards Institution)

    The product standard for rock and glass mineral wool, the material behind loft roll, cavity batts and acoustic quilt. Published 28 Feb 2013, current but under review, and carries Designated status meaning it is a designated standard for UKCA marking. It specifies requirements for factory made mineral wool products with or without facings or coatings used for the thermal insulation of buildings, manufactured as mat blankets, boards or slabs, and covers product characteristics, testing, evaluation of conformity, marking and labelling. Three limits are worth citing: it does not specify what level of any property a product must reach for a particular application, which is set by regulations instead; products with a declared thermal resistance below 0.25 m2K/W or a declared thermal conductivity above 0.060 W/mK at 10 degrees C fall outside it; and it excludes in situ insulation, covered instead by EN 14064 parts 1 and 2, and building equipment insulation, covered by EN 14303. It also states that the performance of a system incorporating these products is not covered, which is why a full wall build-up needs its own assessment.

    Cited in Cavity Wall Insulation Materials Compared, Floor Insulation Materials & Build-ups, Loft & Roll Insulation: Types, Depth & U-values, PIR vs Mineral Wool Insulation Compared and 1 more.

  32. strong RN-21YSR6 cited

    BSI (British Standards Institution)

    The product standard for EPS, the white bead board used for most external wall insulation systems and under many floor slabs. Published 28 Feb 2013, current but under review. It specifies requirements for factory made expanded polystyrene products with or without rigid or flexible facings or coatings used for the thermal insulation of buildings, made as boards, rolls or other preformed shapes including tapered, tongue and groove, shiplap and profiled, and notes the same products are used for sound insulation and in prefabricated systems and composite panels. It sets classes of dimensional tolerance for length, width, thickness, squareness and flatness, the EPS designation code, sampling and conditioning for thermal tests, and the Assessment and Verification of Constancy of Performance regime of type testing plus factory production control. Products with a declared thermal resistance below 0.25 m2K/W or a declared thermal conductivity above 0.060 W/mK at 10 degrees C are outside its scope, as are in situ products, building equipment and industrial insulation, civil engineering applications and beam and block floor systems.

    Cited in Cavity Wall Insulation Materials Compared, EPS vs XPS Insulation: Which & Where, Floor Insulation Materials & Build-ups, Wall Insulation Materials: Cavity, Internal & External.

  33. strong RN-W6XBQJ cited

    BSI (British Standards Institution)

    The product standard for XPS, the coloured closed cell board used below screeds, in inverted roofs and where water resistance matters. Published 28 Feb 2013, current but under review, with Designated status for UKCA marking. It specifies requirements for factory made extruded polystyrene foam products with or without facings or coatings used for thermal insulation of buildings, manufactured as boards including special edge and surface treatments such as tongue and groove and shiplap, and also used in prefabricated thermal insulating systems and composite panels. As with the other 131xx standards it does not set the property level a product must reach for a given application, which is left to regulations. Products with a declared thermal resistance below 0.25 m2K/W or declared thermal conductivity above 0.060 W/mK at 10 degrees C are excluded, as are in situ products, building equipment and industrial insulation covered by EN 14307, and civil engineering applications covered by EN 14934.

    Cited in EPS vs XPS Insulation: Which & Where.

  34. strong RN-03453V cited

    BSI (British Standards Institution)

    The product standard for PIR and PUR boards, the rigid foil faced insulation sold under brand names such as Kingspan and Celotex. Published 28 Feb 2013, listed as Current with Designated status for UKCA marking. It specifies requirements for factory made rigid polyurethane foam products with or without facings or coatings used for the thermal insulation of buildings, made in board form, and the page states explicitly that PU includes both PIR and PUR products, which settles the common confusion about whether PIR has its own standard. It covers multi-layered PU insulation products, product characteristics, testing, evaluation of conformity, marking and labelling, dimensional tolerance classes for length, width, thickness, squareness and flatness, the designation code, and the AVCP regime of type testing plus factory production control. Products with a declared thermal resistance below 0.25 m2K/W or declared thermal conductivity above 0.060 W/mK at 10 degrees C are excluded, as are in situ insulation products and insulation of building equipment and industrial installations.

    Cited in Floor Insulation Materials & Build-ups, PIR vs Mineral Wool Insulation Compared, Wall Insulation Materials: Cavity, Internal & External.

  35. strong RN-3B3DX9 cited

    BSI (British Standards Institution)

    STATUS: CURRENT, and it is the replacement for a standard the notes still cite. BS EN ISO 16535:2019 was published 31 July 2019 and expressly supersedes BS EN 12087:2013, which is WITHDRAWN. It specifies the equipment and procedure for determining the long term water absorption of thermal insulating products, giving two methods: method 1 partial immersion and method 2 total immersion. This is the test behind the WL(T) declared value used to compare rigid boards for below ground, inverted roof and perimeter use, which is why extruded polystyrene (XPS) is specified below damp proof level rather than expanded polystyrene or unfaced PIR. Any note citing BS EN 12087 for water absorption of insulation should be corrected to BS EN ISO 16535. Catalogue page confirms number, title, date, status, the supersession of BS EN 12087:2013 and the two methods; the procedure detail is paywalled.

    Cited in EPS vs XPS Insulation: Which & Where.

  36. strong RN-BNGAID cited

    United Kingdom Accreditation Service

    The live UKAS register of accredited bodies currently under sanction. It records the British Board of Agrement under imposed suspension from 26 February 2026 across all four of its accreditations: ISO/IEC 17065 product certification and ISO/IEC 17021 management systems under reference 0113, ISO/IEC 17020 inspection under 4345, and ISO/IEC 17025 testing under 0357. This is the page to check before repeating any advice that treats a BBA certificate as accredited third party assurance.

    Cited in Breathable Membranes for Roofs & Walls, Brick Slips & Brick Cladding Systems, Cavity Wall Insulation Materials Compared, Damp Proof Membranes (DPM) & DPC: Types & Installation and 7 more.

  37. good RN-2PPZEW cited

    Cavity Insulation Guarantee Agency

    CIGA is the independent agency issuing guarantees for cavity wall insulation across the UK and the Channel Islands. It provides independent 25 year guarantees for cavity wall insulation fitted by CIGA-registered installers, and the guarantee is only valid where the installer was registered at the time of the work, so a homeowner should verify registration before the job rather than after. Guarantee holders can check cover, raise a concern through the register-a-concern route, or use the formal complaints process for a dispute; contact is 01525 853300 or info@ciga.co.uk. This is the source to cite when a note tells a reader how to find out whether existing cavity fill is guaranteed.

    Cited in Insulation: The Complete Guide.

  38. good RN-0YCUN4 cited

    INCA (Insulated Render and Cladding Association)

    INCA's page on how external wall insulation sits inside the PAS 2035 retrofit framework. It defines PAS 2035 as a Publicly Available Specification designed to provide a clear retrofit standards framework for the installation of energy efficiency measures, built to raise standards and consistency in both the design and the installation of those measures and to ensure they are appropriate for the property and will perform as expected. It points to PAS 2035/2030+A1 2022 as the applicable version, and it flags the point most often missed on an EWI retrofit: the requirements for air tightness testing and for ventilation measures that come with wrapping a house. It also links the Retrofit Academy guide PAS 2035 Ventilation for Domestic Retrofit. Use it to explain why a grant funded EWI job carries assessment and ventilation obligations that a straight private render job does not.

    Cited in Cladding and Render: The Complete UK Guide (2026).

  39. good RN-HHDQ4R cited

    Property Care Association

    The PCA's homeowner position on spray foam. Closed-cell foam can create a barrier that traps moisture within the roof cavity, causing condensation build-up in cold weather and potentially timber rot and decay, and its air-sealing can restrict roof space ventilation so a lack of airflow makes the moisture problem worse. Because the foam completely obscures trusses, rafters and sheathing, surveyors cannot visually inspect the timber. The PCA confirms the market consequence directly: concerns raised by valuation surveyors have in recent years concerned lenders, insurers and the wider surveying profession, affecting the valuation of some homes and leading certain mortgage companies to refuse to lend. An industry working group produced new inspection protocols for valuation surveyors, and the PCA points homeowners to designated spray foam assessors.

    Cited in Insulation: The Complete Guide.

  40. supplier figure RN-D7YSW5 cited

    Builder Depot Ltd

    the retail price Builder Depot Ltd publishes for Insulation, Builder Depot, which is the supply figure the cost book records for this item

    Cited in Insulation: The Complete Guide, Solid Wall Insulation: IWI vs EWI.