As a nation, we spend 80-90% of our time indoors, with 63% of the UK workforce working from home either all or some of the time. This means the quality of our homes is integral to the quality of our lives, so housebuilders must design and build homes that provide a comfortable indoor environment. Here Martin Twamley, Technical Director from STEICO looks at the role of wood fibre insulation in creating a ‘healthy home’.
The term ‘healthy home’ refers to a property that has been designed and built to work optimally so it creates an indoor environment that supports and promotes health and comfort. This starts with specification, because the choice of material that a product such as insulation is made from can have a big impact on how the home functions.
There is a wealth of insulation products made from different materials on the market. Many of which are seen as mainstream while others that are perceived as niche, suitable only for certain types of projects.
To some extent, wood fibre insulation has been unfairly categorised as the latter, possibly because it was traditionally used for sustainability focussed projects. It excels in this area because it comprises at least 80% natural wood sourced from PEFC forestry, and binds a carbon dioxide equivalent within the finished insulation board or batt so helps to reduce the project’s carbon footprint. It can also contribute to a home’s energy efficiency strategy.
However, as sustainable construction has become more mainstream, so too has wood fibre insulation – and it offers many benefits to housebuilders who want to ensure their new homes are ‘healthy’.
Delivering thermal comfort – in winter and summer
The primary role of insulation is to increase energy efficiency. Wood fibre insulation can be used to insulate the walls, floors and roof, and is also available in air-injected or rigid board form. By reducing the amount of heat that passes through the building fabric, it allows the heating system to work more effectively, which creates a stable internal temperature and helps to lower energy bills.
It also plays a crucial role in mitigating overheating, which as temperatures are rising, has become a serious threat to health and wellbeing. Approved Document O of the building regulations has been designed to start addressing overheating issues when constructing new-build homes.
What part O fails to consider is the active role the building fabric, and the insulants contained within it, can play in reducing the impact of overheating. Insulation materials like wood fibre have the right balance of low thermal conductivity, high density and high specific heat capacity. This means they offer greater resistance to heat during hot summer days and therefore, actively help to keep internal temperatures within a comfortable range.
Safeguarding indoor air quality
Another factor that contributes to ‘healthy homes’ is indoor air quality (IAQ). This can be affected by VOCs (Volatile Organic Compounds) which can come from chemicals released by products in the home including construction materials, or environmental factors such as mould.
One way to check whether construction products will contribute to healthy homes is to look for third party accreditation. A good example is the ‘Tested and Recommended’ seal of approval from the Institute for Building Biology in Rosenheim, Germany. This certification confirms that materials used meet stringent criteria for low emissions and environmental compatibility, making them suitable for use in buildings where IAQ and occupant health are priorities. The Institute is internationally recognised for its independent evaluation of building products based on their impact on human health and ecological sustainability.
Choice of construction materials can also affect environmental factors. Mould can propagate when moisture condenses on cold surfaces, so controlling moisture in buildings is a requirement of Approved Document C. This is usually achieved by installing a vapour control layer (VCL) on the warm side of the insulation. Continuity of the insulation layer should be maintained throughout the structure to ensure there are no cold spots where moist air can condense.
Wood fibre insulation can be manufactured in dense batts designed for installation between timber studs, joists, or rafters. These batts are held in place purely by friction, without the need for mechanical fixings or adhesive tapes. This installation method reduces the risk of gaps forming within the insulation layer, which can lead to cold spots, thermal bridging, and condensation. The friction-fit system supports the continuity of the thermal envelope and helps maintain consistent thermal performance throughout the building.
In addition to its thermal and moisture management benefits, wood fibre insulation can contribute to improved acoustic performance. The range of possible densities and composition of the material help to reduce airborne sound transmission, supporting quieter indoor environments and enhancing occupant wellbeing by limiting exposure to external noise pollution.
So, as our homes increasingly become the places where we live, work and relax, it’s essential that housebuilders prioritise indoor comfort and wellbeing. Wood fibre insulation offers a compelling solution; it supports year-round thermal comfort, helps safeguard indoor air quality, supports controlling moisture levels, and can provide acoustic benefits – all while contributing to the UK’s wider sustainability goals through its low-carbon credentials. By specifying wood fibre insulation, housebuilders can deliver “healthy homes” that comply with current building regulations, support the expectations of modern living, and ensure resilience against environmental and performance-related challenges into the future.