ºÃÉ«ÏÈÉúTV

• Rapid air change exceeds government legislation
• Filters remove dust – good for allergy sufferers
• Sealed up homes mean warm air cannot escape
• Low toxic materials for carpets

Berkeley Homes has utilised a Canadian system of insulation which makes its buildings super insulated. Adopted for a housing project in Holborough, the Super E system was designed and supplied by Alouette International Housing in Quebec.

There is a debate surrounding the necessity of add-ons of green building. Some argue that all that is needed is very robust insulation, which can keep the building cool in the summer and retain heat during the winter. PV’s and turbines don’t necessarily provide much in the way of energy, which means a properly insulated house will make much of the savings.

Rapid air change

The timber frame homes are constructed from a prefabricated design in factory conditions, where quality control is strictly monitored.

The Super E system effectively seals up the building, with no air in or out. This means that when air exchange falls below 5 to 7 times throughout a building, a Heat Recovery Ventilator is required, which draws heat and moisture from the kitchen and bathroom and pushes it out, then the system draws in cold fresh air, then heating it to maintain a constant temperature.

This ensures that the sealed Super E unit does not become uncomfortable for the occupants of the building. These houses now change the air less than 1.5 times an hour. In a typical home the air changes 12-15 times, creating a drafty and inefficient space, as far as heat retention is concerned. The government has now pushed building regulations to require that air is changed less than 10 times per hour to improve energy efficiency. So these homes go further than the latest government demands.

The timber frame

The timber frame is a mixture of White Spruce, Logepole Pine and Alpine fir from a sustainable source in Quebec in Canada. The manufacturer claims that all wood used on the buildings has a chain of custody to trace all the wood products to source. The roof trusses & Eco Joists are produced in Ramsgate Kent from European Red/White wood imported from Scandinavia, with grades ranging from C16 - 24 and TR 26.

Super E also filters the incoming air to remove dust and pollen particles before it begins circulating around the house which is great news for allergy sufferers. It will help sufferers of asthma, hay fever and skin complaints.

Energy saving building skin

The homes are sealed up so that warm air cannot escape through holes and gaps in the skin of the building.

Berkerley Homes says that the Super E system also helps to regulate three other areas where heat is lost in the home, including the stack effect (when heat rises and cold air is sucked in), the flue effect (when warm air escapes up the chimney) and the wind effect (when a home is subjected to strong, cold winds). Thanks to these innovative building methods, the end result is a naturally warmer home with less demand for central heating.’ They do this using prefabricated 'Fiberock' panel to each skin, with the external panelling and interior plasterboard being added once in the UK. The plaster is a UK Gypsum plasterboard.

These buildings also select low toxic materials for carpets, paints and other interior finishes. Berkeley claims that all their interior finishes will emit low or zero toxic emissions.

The key aspect to these buildings is the skin of the building. They have achieved 'U' values of 0.238 for the walls and 0.136 for ceilings. Energy usage statistics vary widely from apartments to detached and semi-detached buildings, so are not included here.

Berkeley Homes spokesman, John Twycross, however said: "The energy efficiency of the Super E System is oriented toward the major reduction in air leakage to a tested level at 2m³/m² @50pa min and far greater than the current ºÃÉ«ÏÈÉúTV Regulations."

Berkeley now claims it is the largest timber frame builder in the UK, with a keen eye on sustainable building practices.

The fact that it imports a great deal of their timber is one major downside to this building company. Despite this, Berkeley Homes was just awarded a Queens Award for Enterprise in the Sustainable Development section (2008).