New solutions for old stock
Last month the government revealed plans to improve the thermal performance of all UK housing, boosting the energy efficiency of existing homes by 29% in 10 years. Green Homes, Warmer Homes – which follows a similar “pay as you save” proposal from the Conservatives – presents a target of six million homes to be insulated by the end of 2011, all lofts and cavity walls insulated by 2015, and seven million homes to receive an eco upgrade by 2020.
To meet the challenge, manufacturers are introducing insulation systems that incorporate new technology or exploit the recyclability and lower embodied carbon of natural, renewable materials.
Environmental consultants predict high interest in vacuum insulated panels (VIP), made from open pore materials such as pressed powders or glass fibres which are wrapped in a high gas barrier film and then evacuated and sealed. Applied to internal faces of walls, VIPs can achieve the same thermal performance as conventional solutions at a fraction of the thickness.
“VIPs are particularly relevant for listed properties where you can’t insulate the exterior, and where you need to maximise internal space by applying only a thin layer to walls,” says Paul Smyth, sustainability consultant at Inbuilt.
“VIPs can potentially deliver thermal conductivity values which are 20 times better than the best products currently available,” says Bill Butcher ICIOB, director of the Green Building Store.
One manufacturer he mentions is va-Q-tec of Germany, whose panels are covered with a black glass-fibre textile to protect against puncturing.
Moisture build up in walls and under floors is a problem in old buildings, which limits the effectiveness of loose, natural insulation materials such as wool, which get damp and mouldy.
Second Nature’s EdenBloc35 panels solve the problem by incorporating compressed recycled wool fibres into low-density rigid insulation panels, therefore combining low thermal conductivity with the breathability of natural fibres. “Traditionally natural materials have limited use, particularly in damp situations, but EdenBloc35 is a stable material that won’t cause mould. It bridges the gap between synthetic foams and natural fibre insulation,” says Butcher.
Also designed to insulate damp interior walls in older buildings is Calsitherm Climate Board from Ecological Building Systems. Made from calcium silicate, a micro porous mineral material with good insulation properties, the material’s “capillary” action helps regulate humidity and stops mould forming on its surface.
In many properties, windows rather than walls are responsible for the main heat loss. But new technology from SeriousMaterials is claimed to cut heat loss without the need to replace the existing frames.
The technology is being used on 6,500 windows in the Empire State Building in New York. The panes are removed and “super-insulation” achieved by adding new spacers, a suspended coated film and a special gas fill between the existing panes. The glazing is then re-installed into the frames. The new windows reduce solar gain by more than 50% and increase thermal performance by up to four times, says SeriousMaterials.
“This technology could save millions of pounds if implemented across the UK,” says Bertie Dixon, consulting engineer at services consultant Max Fordham.
The National Insulation Association (NIA) has welcomed a joint forum between the government and the financial services industry to develop “pay as you save” arrangements that will help householders spread the cost of installing energy efficiency measures under the proposed Green Homes, Warmer Homes initiative (see main story).
According to the NIA, the UK housing stock of 24.5 million includes nine million with cavity walls which have not been insulated.
A further seven million have solid walls that need insulating, including solid brick, solid stone, pre-1944 timber frame and non-traditional construction, while 13 million have 100mm or less of loft insulation, compared to the 270mm required for new homes.
NIA chief executive Neil Marshall said: “There must be a major expansion of the solid wall insulation industry capacity and infrastructure over the next few years.”
Recycled plastics form the basis of AthyECOSlate, a roofing tile from Linpac designed as an alternative to traditional slate. The tiles are manufactured in Ireland and made from a bespoke UV-stabilised polypropylene mineral composite. They have the same look and feel as slate, but are resistant to colour fading, cracking and breakdown, says Linpac. The tiles are also fungus and moss resistant and non-porous to prevent water damage and frost formation, while installation is typically 30-40% faster than traditional slates.
Sylvactis 55 FX is a wood-fibre insulation made entirely from waste wood, which combines low thermal conductivity and high thermal inertia for comfort in both winter and summer.
Suitable for use in roofs, walls and floors, the insulation batts are made from waste from local sawmills using wood from sustainably managed forests. Batts are available in thicknesses of 40mm to 140mm and are resistant to air infiltration and sagging.
Mossgo-Pro is a powerful surface cleaner from TVSP which removes moss and lichen from roofs.
The shampoo solution contains a biocide which kills micro-organisms, including viruses, bacteria and algae. When the algae within lichen and moss die, the whole organism dies and disappears.
The technique is an alternative to pressure washing and removes the risk of water ingress or surface degradation, says TVSP. Roof surface finishes recover their original lustre over a few days to a few weeks.