Yes, wood fibre insulation is suitable for mainstream housebuilding. It can be used to insulate the walls, floors and roof, and is also available in air-injected or rigid board form.
As it is formed from 80% of wood fibre and the naturally derived raw material comes from PEFC certified forests. Insulants like wood fibre are often seen as materials suitable for projects whose main focus is sustainability but that is changing fast.
Embodied carbon, overheating, waste reduction, moisture control and health and wellbeing are just some of the challenges faced by housebuilders as they seek to deliver a development that meets their sustainability criterion.
In this piece, we will show why wood fibre insulation offers a lot more to housebuilders. We will look at some of the key issues and first explain the drivers for housebuilders and then show how wood fibre insulation could help.
How can wood fibre insulation help reduce embodied carbon for mainstream housebuilding?
With the government’s target[1] for the UK to become net zero by 2050, there’s an increasing pressure on housebuilders to play their part in reducing the embodied carbon of new homes. The embodied carbon of a construction product is the carbon emissions associated with its manufacture, transportation, installation, use on site, deconstruction and disposal. Where a product has an EPD (Environmental Product Declaration), the housebuilder can compare the embodied carbon of one product with another.
Embodied carbon is currently unregulated, even though it makes up 20% of the UK’s built environment emissions[2]. However, there is growing talk of legislation being introduced to regulate embodied carbon – and the construction industry has already drafted a potential Approved Document[3] called ‘Part Z’.
There are already methods available from the BRE[4] and RICS[5] that can be used by developers to calculate the embodied carbon of whole buildings. This helps assess the carbon impact of different materials – such as wood fibre insulation – against another, such as mineral wool insulation to see the effect at a building level.
It could therefore be only a matter of time before mainstream housebuilding must meet regulated targets for embodied carbon.
How wood fibre insulation can help reduce embodied carbon
When developers need to determine the carbon contribution of various construction materials used on a project as a measure of their sustainability, they look at each product’s Environmental Product Declaration (EPD). Wood fibre insulation from STEICO is formed from 80% of wood fibre and the naturally derived raw material comes from PEFC certified forests. Many of STEICO’s products have EPDs that reflect the bound carbon dioxide equivalent content of the wood. For example, STEICOuniversal dry binds 260kg CO2eq6 and can thus contribute to climate protection making it a viable option for developers who are looking to reduce the embodied carbon within their projects.
On top of this, its insulation properties help increase the energy efficiency of a building and reduce its associated carbon emissions.
Gs8, the award-winning sustainable housebuilder has already made the decision to impose their own targets on embodied carbon. They are using STEICO wood fibre insulation on Carpenters Yard – the UK’s largest ‘Zero Bills’ housing development.[6] It’s being built in line with gs8’s ‘Planet Positive Framework’ where the development goes further than net zero and is defined as ‘carbon negative’. It stores more carbon than is created over its lifetime. Its low embodied carbon made it a highly suitable choice for the project’s sustainability goals.
The gs8 approach to embodied carbon may be an outlier now. However, maybe other housebuilders will be required to follow suit.
What part can wood fibre insulation play in helping to mitigate overheating in housebuilding?
With hotter summers, the risks of overheating are increasing. In the Committee for Climate Change report[7], it states that under current UK weather conditions, 50% of existing UK homes will suffer from overheating risk. If global temperatures were to rise by 2°C, this number would rise to 90%.
Almost 5.5 million children - over half of those in England - are living in homes at risk of overheating, according to new analysis of the English Housing Survey 2022 by the Resolution Foundation think tank.[8]
In 2021, a new Approved Document[9] (Part O) was introduced into the building regulations to start to address overheating issues when constructing new-build homes. This regulation is driving housebuilders to act. According to the Met Office, record breaking weather is now the norm in the UK’s future[10] so it is likely that further revisions of Part O will become more prescriptive and onerous to meet the increased overheating threat.
How wood fibre insulation can help mitigate overheating
Wood fibre insulation doesn’t just keep the heat in during the colder months. It can also help to keep heat out during hot summer days and evenings.
Wood fibre insulation is characterised by a higher raw density than many conventional insulating materials. This means it can offer greater resistance to heat radiation due to its higher heat storage capacity.
Martin Twamley, Technical Director at STEICO, explains the benefit of this extra thermal mass: “Not all insulation works the same when it comes to keeping your home cool in summer. Lighter, less dense materials don’t hold heat very well, so the sun’s warmth can pass through more quickly and raise the internal temperature. That’s where wood fibre can make a real difference. Its properties allow it to store and hold the heat within the material itself, helping to keep rooms cooler during the day. It’s a simple way to reduce the risk of overheating and allow the building fabric to do the work—without needing to rely on air conditioning, which can be expensive to install and run.”
How can wood fibre insulation help housebuilders reduce waste?
A huge amount of waste is generated by construction. Government data[11] shows that in 2020, an estimated 59.4 million tonnes of non-hazardous construction and demolition (C&D) waste was generated. 55 million tonnes were recovered with the rest going to landfill. That is a lot of waste going to landfill at considerable cost to the housebuilder. In fact, construction waste can cost up to ten times more than a company expects. Research[12] in 2023 suggested that the expected cost of an 8-yard skip was around £300, but in fact the true cost was closer to £1,900. It’s not surprising then that housebuilders need comprehensive plans to reduce site waste.
How does wood fibre insulation help housebuilders with moisture control?
Control of moisture in buildings is a requirement of ‘Approved Document C[13]: Site preparation and resistance to contaminants and moisture’ of the building regulations. The document references the standard BS 5250:2021 Management of moisture in buildings[14]. This has guidance on how moisture is managed to prevent the build-up of condensation that can pose health risks and also damage the fabric of the building.
How wood fibre insulation helps to control moisture
Wood fibre insulation materials are diffusion open allowing water vapour to safely pass through the material. Insulation that is diffusion closed does not. Vapour control layers (VCLs) are used to help control the level of internal moisture entering the building fabric. They are placed on the warm side of the insulation.
As Martin Twamley explains: "The combination of a VCL, which controls the amount of water vapour that can enter the building fabric, and wood fibre insulation, which allows any that does enter to naturally migrate out, creates the ideal scenario for a risk-free approach to moisture management. Far too often an approach is taken that tries to block moisture movement, either with a 'vapour barrier' or diffusion closed material and this can end up increasing risk as moisture can get trapped within the building fabric. This can have long term consequences, not just in terms of condensation or mould but even for the structural performance of the building itself”
How can wood fibre insulation contribute to improved indoor air quality?
As we spend 90%[15] of our time indoors, and the average Brit spends 53 years of their life inside[16] it’s important that the indoor environment is one that promotes health and wellbeing. The APPG (All Party Parliamentary Group) for Healthy Homes and Buildings points out that ‘Noise, poor ventilation and air quality also impact on the general health and well-being of those who are living and/or working in poor quality and unhealthy environments’[17].
It estimates that poor quality housing costs the NHS £1.4 billion per year. While the affected homes are not likely to be new builds, there is a pressure on housebuilders to ensure that new stock does not suffer the same fate as existing stock in the future.
How can wood fibre insulation help?
Products such as STEICOspecial dry carry the ‘Tested and Recommended’ seal of approval from the Institute for Building Biology in Rosenheim, Germany — an organisation known internationally for evaluating how building materials affect health and the environment. Their approval reflects the product’s low emissions and suitability for creating healthier indoor spaces
Due to its density and composition, wood fibre insulation can also help to improve the acoustics of properties. The insulation helps to keep noise pollution out of the home that could otherwise have detrimental effects on the health and wellbeing of the occupants.
Wood fibre insulation is available in dense batts that are used to insulate between timber studs, joists or rafters. These batts are kept in place purely by friction, with no additional fixings or tapes required. This reduces the risks of gaps in the building fabric which can lead to cold spots and condensation issues. This helps to maintain the thermal integrity of the insulation layer.
Where can I find more information aboutwood fibre insulation solutions?
STEICO is the world’s largest producer of wood fibre insulation. We have a comprehensive range of products suitable for use in walls, floors and roofs. All are manufactured to EN standards or have European Technical Approvals and use PEFC certified softwood and many have third party verified EPDs.
To enquire about using our wood fibre insulation on your next project, please contact our expert team who will be happy to help.
[1]www.gov.uk/government/publications/net-zero-strategy
[2]ukgbc.org/news/ukgbc-joins-industry-leaders-calling-for-government-to-regulate-embodied-carbon/
[4]breeam.com/about/net-zero-carbon
[5]www.rics.org/profession-standards/rics-standards-and-guidance/sector-standards/construction-standards/whole-life-carbon-assessment/unlocking-sustainability-exploring-rics-whole-life-carbon-assessment-wlca-standard
[6]www.gs8.co.uk/news/press-release-carpenters-yard-launch/
[7]www.theccc.org.uk/wp-content/uploads/2022/10/Addressing-overheating-risk-in-existing-UK-homes-Arup.pdf
[8] Housing Outlook Q3 2022 • Resolution Foundation
[9]www.gov.uk/government/publications/overheating-approved-document-o
[10]www.metoffice.gov.uk/about-us/news-and-media/media-centre/weather-and-climate-news/2025/annual-climate-stocktake-shows-weather-records-and-extremes-now-the-norm-in-uk-climate
[11]www.gov.uk/government/statistics/uk-waste-data/uk-statistics-on-waste.
[12]www.be-st.build/news/the-true-cost-of-waste-the-hidden-price-construction-is-paying-for/
[13]assets.publishing.service.gov.uk/media/5a8192a0e5274a2e8ab54b5f/BR_PDF_AD_C_2013.pdf
[14] BS 5250:2021 Management of moisture in buildings
[15]post.parliament.uk/research-briefings/post-pb-0054/
[16]www.openaccessgovernment.org/britain-becomes-indoor-nation/49636/