The UK has recognised that the environmental impact of construction will have to be tackled if it is to meet ambitious climate change targets. The industry produces 10 per cent of the UK’s greenhouse gas emissions, and 50 per cent of all the materials extracted from the Earth’s crust are used in construction; therefore a fundamental rethink of building material used and associated technology implementation is needed. But can low costs and renewable construction be compatible? This question was answered via this project; The Renewable House. This unique housing project was delivered by NNFCC and tested the suitability of renewable materials in the construction sector.

In 2009-10, the Government invested £6.3m under the Low Carbon Investment Fund (LCIF) to support the construction of 283 low carbon affordable homes; built with a range of innovative renewable materials.  The aim was to spur interest in and the development of the renewable construction materials industry, and to engage the affordable housing sector in the low carbon agenda. With support from DECC and funding from the Low Carbon Innovation Fund (LCIF), a further project was commissioned to examine the energy performance of a selection of the renewable housing within the new developments.

The Renewable House possessed a timber frame and Hempcrete® walls and was subjected to co-heating tests. The study aimed to show how practical, affordable, sustainable and scalable these materials can be, offering an alternative for mainstream style homes
This report focuses on the results of the co-heating tests carried out at the NNFCC Renewable House at the Building Research Establishment (BRE) in Watford and at Long Meadow, Diss. The houses were constructed from Hempcrete during the 2011/2012 winter. This was done as part of The Renewable House project. Monitoring equipment was obtained from Carnego Systems was installed and used for the test. Electric heaters and thermostats for the co-heating test were obtained through an HCA grant.

Construction methods of Hemcrete houses can be up to 30% less than traditional brick-block methods. Hemcrete houses can cost less to heat and occupants can reduce their energy consumption costs. However, ensuring lower energy consumption by occupants was dependent on rigorous control of construction, and appropriate use of novel renewable heating using air-source heat pumps and mechanical ventilation systems. ​

The work and its follow-up stage has provided important lessons and learning points for the construction industry, leading to the development of modified construction methods, including offsite hempcrete panel production to help improve the build performance of such novel materials.

The report concludes that Hemcrete has considerable potential for transforming the UK construction industry. When used correctly, Hemcrete can facilitate substantial carbon emissions savings for the UK.​​

For detailed information on the tests please purchase the full report, or become an NNFCC subscriber.

You may also be interested in:

• Our techno-economic services
• Regional Renewable Energy Capacity Assessments ​
• Past projects: Biohorizons and BioBaseNWE
• Current projects AgroCycle BioBase4SME SuperBIO

Talk to the experts