Cellulose-based building materials: use, performance and risk (NF55)
Interest and awareness about the embodied energy associated with the production, use and disposal of construction materials remains topical, resulting in traditional cellulose-based building materials such as thatch, cob, hemp and lime, or straw bales being re-examined as potential low impact building materials, products and systems.
This report provides a brief history of cellulose-based building materials, and reviews the current developments in their use. It looks at the use and performance issues of such materials, examining the potential benefits and associated risks – informing the debate and resulting in a better understanding about the use of low impact building materials. In addition, the report also provides examples of recent projects built in the UK.
Summary of content
Recent work on embodied energy has seen traditional cellulose-based materials being re-examined as potential low impact construction materials. There are many examples of using crop-derived materials in construction, both traditional ones such as thatch and cob, and more recently hemp and lime in addition to straw bale construction. There has been increased interest in using these materials.
Early examples of cellulose-based construction, such as a social housing development for the Suffolk Housing Society at Haverhill in Suffolk, the Renewable House at the BRE Innovation Park and the BaleHaus at Bath University, have been surpassed by much larger social housing and commercial projects. The 3000 m2 Adnams Distribution Centre (hemp and lime), the project at Denmark Lane, Diss, Norfolk (114 homes using hemp and lime), and the Waddington project in Lincolnshire (straw bales) are examples of completed developments.
There have also been developments in off-site construction using cellulose materials. Developments using straw bale panels and hemp and lime panels have been used to construct around 20 buildings in the UK including the Cheshire Oaks Marks & Spencer retail store near Ellesmere Port.
If use of these materials is to reach its full potential then questions on buildability, long term performance and risks need to be reviewed, assessed and evaluated. This report uses the latest findings from BRE, BBA and other sources, as well as from some of the cellulose-based material companies themselves, to provide a balanced overview.
The broad aims of the report are to:
- clarify the nature and role of cellulose-based building materials
- review current developments
- describe the major factors to consider when using cellulose materials.
The study drew on the activities of BRE and their partners enabling access to representatives of the natural fibre building sector, associated supply chains and other research programmes. BRE undertook the role of technical lead through its existing expertise and that of the BRE Centre of Innovative Materials at the University of Bath. The Centre for the Built Environment (CBE)1, part of the Adapt Low Carbon Group at the University of East Anglia, provided a focal point for contact with supply chain partners.