All the homes at Long Meadow have external walls built with a timber frame and Hemcrete®, a carbon negative building material that replaces the traditional bricks and blocks of housebuilding.
As well as being part of the structure, the 300mm thick walls are part of the insulation and the “thermal mass” which keeps the building cool in summer and warm in winter.
Hemcrete® is made from the woody part of the hemp plant, bound together with lime, water, and a special ‘glue’. As the hemp grows here in East Anglia, it locks up carbon dioxide from the atmosphere enabling us to build a house that ‘contains’ 35 tonnes of carbon dioxide less than a traditional house. It is a truly sustainable and renewable material.
It may be new and innovative but there is no need to worry, Hemcrete® is built to last and the homes at Long Meadow carry a 10 year warranty as with any other new house. And the walls are just like normal walls – you can still knock nails into them!
The Hemcrete® walls do not need any more insulation – they are the insulation!
There is insulation in the roof though, and again this is a natural fibre insulation that is not only effective but sustainable, because it has come from a natural material.
The windows are triple glazed and wooden framed, thus combining sustainability with a high degree of insulation.
- Solar Energy
Unlike many developments of “Eco houses” Long Meadow doesn’t rely on solar energy, and you will not see solar or ‘PV’ panels on all the roofs.
However the blocks of apartments at Long Meadow does use some solar thermal water heating to achieve the percentage improvement in energy efficiency demanded by the Code for Sustainable Homes. Apartments are inherently more efficient than houses, and it is therefore more difficult to achieve the percentage improvement with the building fabric alone.
Almost everything that has gone into making Long Meadow has been or can be recycled. The materials are mostly renewable, and can be recycled if future generations want something different.
Recycling bins are provided in all the properties supported by the Council’s recycling collection scheme.
The traditional boiler has been replaced with an air source heat pump, a fast-emerging technology that works like a reverse fridge, squeezing all the warmth out of the air (even when there isn’t very much) and using it to heat water. This water heats the house through an underfloor heating system and radiators, while also providing your hot water.
- Mechanical Ventilation and Heat Recovery
Hidden up in the roof or above the ceiling is a simple device called a “Mechanical Ventilation and Heat Recovery System” or “MVHR”. It is elegant in its simplicity, but very effective. An MVHR extracts warm air from the kitchen and bathroom, passes it through a filter, mixes it with cooler air from outside, and then re-circulates it, thus keeping the overall temperature in the house even and comfortable.