The UK’s 2026 definition of “green building material” comes from PAS 2035 and the Future Homes Standard
The term “green building material” is not a marketing label in UK regulations. It is defined by two key standards. The Future Homes Standard, updated in 2025 and enforced from that year, sets maximum fabric energy efficiency targets for all new homes (DESNZ, Future Homes Standard 2025 consultation response, GOV.UK). This effectively requires materials with low embodied carbon and high thermal performance.
Green building materials UK 2026 are defined by PAS 2035 and the Future Homes Standard. They must have low embodied carbon and high thermal performance. Glazing is standard-rated for VAT at 20%. The zero rate for energy-saving materials covers insulation, heat pumps and solar panels; HMRC names secondary and double glazing as excluded (VAT Notice 708/6).
- Check PAS 2035 compliance before buying insulation materials for retrofit.
- Future Homes Standard sets max fabric energy efficiency for new homes.
- VAT on energy-saving materials is 0% until March 2027.
- The Great British Insulation Scheme closed on 31 March 2026. It funded insulation measures only and never covered windows or glazing.
- ECO4 funds insulation only if on the TrustMark-approved product list.
- The UK's 2026 definition of "green building material" comes from PAS 2035 and the Future Homes Standard
- Glazing is standard-rated for VAT at 20%. The zero rate for energy-saving materials covers insulation, heat pumps and solar panels; HMRC names secondary and double glazing as excluded (VAT Notice 708/6).
- The most common certified green building materials for UK homes in 2026
- Quick numbers – cost, U-value, and grant availability for key green materials in 2026
- Green building materials reduce a home's operational carbon, but embodied carbon is now the key metric
- To receive any grant or subsidy, the material must be installed by an MCS-certified or TrustMark-registered contractor
- How to confirm your home is eligible for green material grants in 2026
PAS 2035:2023 is the retrofit standard for existing homes. It defines acceptable materials for insulation, air-tightness, and moisture management (British Standards Institution, PAS 2035:2023). In UK regulatory terms, a green material reduces operational energy use (measured by U-values and air permeability) and has a lower Environmental Product Declaration (EPD) score than a conventional alternative.
Glazing is standard-rated for VAT at 20%. The zero rate for energy-saving materials covers insulation, heat pumps and solar panels; HMRC names secondary and double glazing as excluded (VAT Notice 708/6).
VAT on energy-saving materials is reduced to 0% until March 2027. This covers insulation, heat pumps, solar panels, and biomass boilers (HMRC, VAT on energy-saving materials, 2026). The Great British Insulation Scheme closed on 31 March 2026. It funded insulation measures only and never covered windows or glazing.
The Boiler Upgrade Scheme (BUS) covers heat pumps but not the building fabric itself. The material cost of the heat pump is included. ECO4 can fund insulation materials for low-income, low-EPC homes, but the material must be on the TrustMark-approved product list (GOV.UK, ECO4: Eligibility and rules).
The most common certified green building materials for UK homes in 2026
Wood fibre insulation (brands include Steico and Pavatex) has a U-value of 0.038 W/m²K. It is certified by BBA or KIWA and used for internal and external walls and roofs (BBA certificates). Hempcrete blocks (e.g., Hempitecture, Tradical) have a U-value of 0.06 W/m²K. They are used for non-load-bearing walls and provide good thermal mass and moisture regulation.
Recycled glass wool (brands include Knauf and Isover) has a U-value of 0.032 W/m²K. It is PAS 2035-compliant and common in cavity wall and loft insulation (MCS product directory). Aerogel-based insulated render (e.g., Fixit 222) has a U-value of 0.015 W/m²K. It is used for solid wall insulation where space is limited (DESNZ, Energy Performance of Buildings: Approved Document L, 2021 updated 2025).
Quick numbers – cost, U-value, and grant availability for key green materials in 2026
| Material | Typical cost per m² (installed) | U-value (W/m²K) | Typical lifespan (years) | The Great British Insulation Scheme closed on 31 March 2026. It funded insulation measures only and never covered windows or glazing. | Glazing is standard-rated for VAT at 20%. The zero rate for energy-saving materials covers insulation, heat pumps and solar panels; HMRC names secondary and double glazing as excluded (VAT Notice 708/6). |
|---|---|---|---|---|---|
| Wood fibre insulation | £40–£70 | 0.038 | 50+ | Yes | Yes |
| Hempcrete blocks | £60–£100 | 0.06 | 100+ | Limited | Yes |
| Recycled glass wool | £15–£30 | 0.032 | 40+ | Yes | Yes |
| Aerogel render | £120–£200 | 0.015 | 30+ | Limited | Yes |
Costs vary widely depending on house size and installer. Source: DESNZ, Cost of installing energy efficiency measures, 2025; Energy Saving Trust, Insulation cost guide, 2026; MCS product directory.
Green building materials reduce a home’s operational carbon, but embodied carbon is now the key metric
Operational carbon (from heating and lighting) is reduced by materials with low U-values. The Future Homes Standard targets a 75–80% reduction in operational carbon compared to Part L 2013. Embodied carbon (from manufacturing, transport, and disposal) is measured via EPDs. The UK Green Building Council recommends a maximum of 500 kgCO₂e/m² for new build fabric (UKGBC, Net Zero Carbon Buildings: A Framework Definition, 2024).
Materials like hempcrete and wood fibre have negative or low embodied carbon. Hempcrete is estimated at -100 to -150 kgCO₂e/m³. Conventional mineral wool has around 40 kgCO₂e/m³ (BRE, Green Guide to Specification, 2025; DESNZ, Embodied carbon in construction: policy paper, 2026).
To receive any grant or subsidy, the material must be installed by an MCS-certified or TrustMark-registered contractor
GBIS, ECO4, and BUS all require the installer to be registered with TrustMark. For heat pumps, the installer must also be MCS-certified. For insulation materials, the installer must hold a PAS 2035-compliant qualification (e.g., from Elmhurst Energy or Stroma) and use materials from the TrustMark product list (Ofgem, ECO4: Installer requirements, 2025).
Homeowners should check the MCS installer database at mcscertified.com and TrustMark at trustmark.org.uk before signing a contract (TrustMark, PAS 2035 retrofit standards, 2026; MCS, Find an installer, 2026).
How to find a TrustMark registered installer for your home
How to confirm your home is eligible for green material grants in 2026
Check your Energy Performance Certificate (EPC) rating. GBIS and ECO4 require an EPC of D, E, F, or G for most measures. The Great British Insulation Scheme closed on 31 March 2026. It funded insulation measures only and never covered windows or glazing. The Great British Insulation Scheme closed on 31 March 2026. It funded insulation measures only and never covered windows or glazing.
For the Boiler Upgrade Scheme, your home must have a valid EPC with no outstanding recommendations for insulation. The heat pump must be MCS-certified. If you live in a listed building or conservation area, you may need additional planning permission. Check with your local authority before purchasing materials (Historic England, Energy efficiency in listed buildings, 2024).
Frequently Asked Questions
Under UK regulations, a green building material reduces operational energy use (measured by U-values and air permeability) and has a lower Environmental Product Declaration (EPD) score than a conventional alternative. PAS 2035 and the Future Homes Standard define these requirements.
VAT on energy-saving materials is reduced to 0% until March 2027, covering insulation, heat pumps, solar panels, and biomass boilers (HMRC, VAT on energy-saving materials, 2026). This reduces upfront costs.
The Boiler Upgrade Scheme covers heat pumps.
Wood fibre insulation (brands like Steico and Pavatex) has a U-value of 0.038 W/m²K and is BBA or KIWA certified. Other materials include sheep's wool, cellulose, and rigid PIR boards with low embodied carbon.
Yes. In UK regulatory terms, a green material must have a lower Environmental Product Declaration (EPD) score than a conventional alternative. This is required for PAS 2035 compliance and many grant schemes.
