Reducing Energy Consumption

The UK’s net zero targets can only be achieved if its housing stock is improved and made more energy efficient. One Yorkshire developer is doing just that with the help of specialist insulation.

Four years ago, Leeds-based sustainable developer Citu set out to create homes 10 times more energy efficient than typical UK houses. To do this, the company invested in a state-of-the-art production facility where all the components for its properties are built offsite.

Thermal performance is critical to energy efficiency. Citu wanted to go far beyond the regulations to achieve wall build-ups with an extremely low U-value of just 0.10W/m2K. This is at least three times better than the U-value achieved in most new build homes and fifteen times better than older houses. Citu turned to Knauf Insulation for advice and support in developing the offsite capability required for this level of thermal performance. Knauf Insulation’s technical support team undertook extensive calculations and recommended the Blowing Plate Insulation System to install Supafil Frame – a high performance, non-combustible blowing wool.

Supafil Blowing Wool lends itself to offsite production because it completely fills the cavity, without any voids even around complex penetrations – something that can occur when insulation slabs or rolls are cut to size. It is also a dry process, so operatives are not exposed to any harmful chemicals and it doesn’t require a dedicated production line. Instead, the system comprises a blowing machine and a filling plate. The system is modular allowing for phased investment. Citu opted to install the blowing machine in phase one, which allowed them to manually fill the panels. Phase two saw the addition of the blowing plate, semi-automating the process.

Supafil Frame can be run by a single operator, fits easily into the existing production line, and can even be moved quickly and swiftly to other areas in the manufacturing facility depending on Citu’s volume capacity requirements. Knauf Insulation’s technical support team provided full training and support during each phase of installation.

 Low Carbon Homes

Insulating the panels

Citu homes are manufactured from timber panels with a 300mm cavity. The blowing plate is positioned over the panel completely covering the cavity. Supafil is then blown into the wooden frame to the specific parameters of each panel. All cavities are filled to the correct thickness: something that has been carefully calculated and tested by the Knauf Insulation to ensure settlement does not occur. And because the machine is programmed to install the exact quantity of insulation required, there’s no waste. Supafil is a high-performance Blowing Wool. It is non-combustible with Euroclass A1 Reaction to Fire Classification rating as well as providing excellent thermal and acoustic performance. It contains a silicone-based additive to ensure it is water repellent. As well as providing excellent thermal performance, Supafil has great sustainability credentials. Knauf Insulation’s glass mineral wool contains up to 80% of recycled content. This reduces the amount of virgin materials used and prevents around 60,000 tonnes of glass a year (350 million bottles) from going to landfill or polluting the environment. Knauf Insulation has also invested in advanced compression packaging. This means there’s less packaging used, so fewer lorries on the roads leading to a reduction in transport The Citu Home uses a timber framed carbon emissions. All of which helps to support design, so each house stores 23 Citu’s goal that every home should be carbon tonnes of carbon and prevents and zero to manufacture. By combining modern prevents the emissions of 88 tonnes of methods of construction with the very highest carbon dioxide, compared to building levels of thermal performance, Citu and Knauf an equivalent masonry house. That’s Insulation are creating homes that reduce roughly the same as taking 19 cars of the road for one year. Older houses have U-values of energy consumption and carbon emissions – around 1.5 W/(m2K). Typical newbuilds are around 0.3-0.6 W/(m2K). The walls in Citu houses homes that are fit for the future. achieve U-values of 0.1 W/(m2K). When combined with the Citu homes’ other features it means energy requirements are between 7 and 10 times lower than the UK average house. More at  www.citu.co.uk  www.knaufinsulation.co.uk