Suffolk homes debut carbon ‘negative’ spray-on hemp and lime

The 26 affordable homes in Clay Fields in the Parish Council of Elmswell have all been built using sustainable construction materials, including a thermal hemp-lime walling solution called Hemcrete.

The spray-on material, produced by a company called Lime Technology, is a blend of hemp shiv and a lime based binder, which together form a bio-composite building material.

Hemp, in common with all similar plants, captures CO2 and releases oxygen during its rapid growth. Furthermore, this captured carbon is then locked into the fabric of the buildings constructed.

It is estimated the use of Hemcrete at Clay Fields will enable the 'locking up' of around 65 tonnes of carbon dioxide.

The Clay Fields housing project, which consists of nine three-bed houses, 13 two-bed and four one-bed flats, has been designed by architects Riches Hawley Mikhail with the explicit brief of creating high-quality low carbon homes, without using highly-visible environmental features, such as solar panels or wind turbines.

The homes, which are all of a timber-frame construction, are orientated to maximise the heat of the sun and generate the best possible light with the positioning of the windows such as to get optimal gain between solar and daylight.

A sustainable ventilation system allows the homes to be ventilated naturally in the summer and via a mechanical system in the winter that removes 80 per cent of heat from outgoing air and uses it to heat incoming air.

Other energy-efficient features include a biomass community heating system – fuelled by locally-sourced wood chips – and rainwater recycling.

Riches Hawley Mikhail was commissioned to do the housing project in 2006 following a RIBA design competition led by Orwell Housing Association in partnership with Elmswell Parish Council, Mid Suffolk District Council and the Suffolk Preservation Society. The competition was a response to the lack of affordable housing for local people in a rapidly-growing commuter belt.

Stephen Javes, chief executive of Orwell Housing Association, said: “We are very proud of this new development at Elmswell, not only because of its sustainable and energy saving features but because it fulfils our major aim of creating affordable homes which are attractive and good to live in and which add value to the local community.”

Riches Hawley Mikhail, which was established in 2005, is concerned with sustainable designs. It is currently working on other housing projects in Liverpool, London and Manchester.

Hemcrete has been previously used in block form in Adnams Brewery Distribution Centre in Southwold, Suffolk, where 150 tonnes of Co2 has been locked up in the warehouse walls.