The sustainable builder BaleHaus recently constructed several energy-efficient homes, which were built using a prefabricated straw insulation system made by the company ModCell. BaleHaus is actually made up of 3 firms working together, namely Cadan Developments, ModCell, and White Design. So far the group has built several different sized homes, from townhouses to apartments, which goes to show just how versatile the straw building system can be.
Straw insulation is not a new thing, but ModCell has taken it a bit further by offering prefabricated panels that are structurally very sound, offer great insulation properties, and will last a long time. The panels they offer are made up of a timber frame packed with deep straw bale, which is then topped by a wood fiber breather board. These prefab panels are easy to use when building a home, and can also be easily clad with brick, wood, or slate.
According to ModCell, using these insulation panels can reduce the heating bill of an average household by as much as 90 percent. They arrived at this calculation by measuring the performance of their recently completed LILAC housing project in Leeds, England. In this complex, a four-month winter heating bill for a one-bedroom came to just $27.50, and $76 for a four-bedroom house. ModCell also offers panels that are Passivhaus certified, but they were not used for the LILAC project.
Strawbale panels are also highly fire resistant, with test placing them at over 2 hours, which is 4 times the required time according to UK building regulations. A structure built using these panels is also capable of withstanding hurricane force winds of up to 120 mph (193 km/h) with no problem. The walls, roof and floor of a home built using ModCell panels have a U value of 0.15 W/m2K.
Other sustainable techs installed in the homes constructed by BaleHaus include rooftop mounted photovoltaic arrays, rainwater harvesting systems, and air-source heat pumps. The structures were also fitted with triple-glazed windows and doors with a U value of 1.16 W/m2K.