Hempcrete as external cladding

THE NEES (natural Energy efficiency and Sustainability Programme began as an idea developed by the Cork Centre for Architectural Education. CCAE is a newly formed architectural school and research centre on building design set up jointly by University College Cork and the Cork Institute of Technology.

The aim of the Project is to investigate the potential and feasibility of popularising the application renewable and recycled natural materials for the production and installation of products to improve the energy efficiency of new and existing buildings. Also, to identify and promote local design and installation services available for the application of these products or based on sustainable natural processes.

Energy effienct timber buiding in Greenland

In achieving this aim, CCAE has entered into partnership with seven social enterprises and  academic and research agencies In Europe’s Northern Periphery , comprising  western and Northern Ireland, Scotland, the Scandinavian countries and Greenland, and secure funding from the European Union for the development of three-year project to explore and develop this theme.

There has also been considerable commercial development of high-tech solutions for energy efficiency, including chemical and industrially manufactured products and processes, nanotechnology, the use of IT in smart buildings and smart grids, etc. in contrast, there has been a notable lack of research and development of products and services based on natural products and processes.

Hempcrete retrofit Ireland

In Ireland, grants for retrofit  of existing homes  (under the Warmer Homes and Greener Homes Schemes for example, is limited to energy-intensive industrial and petrochemical products, and no single technology for retrofit of existing walls based on use of natural materials has been approved for subsidy.

This limitation has consequences for sustainability, including the fact that such products are usually manufactured outside of the region, though energy-intensive industrial processes, with a considerable environmental impact. They have then to be transported in from other regions.

On the downside, little use is made of local products, especially agricultural products and by-products that could achieve a similar effect. The production or installation of these materials rarely promotes new skills locally, or the development of the local economy, other than in a limited sales or installation role. The building and refurbishment sector has become dependent on these imports, when there are potentially viable products available locally that could be developed and delivered locally.

Examples of the types of products available are:

  • timber from renewable forests,
  • hemp and lime,
  • straw bales
  • recycled paper.

Examples of services that could help reduce energy use are:

  • timber frame design
  • bioclimatic design,
  • energy and sustainability assessments
  • local behaviour change training.

These products and services are

  • less capital intensive,
  • more locally based,
  • consume less rare and finite materials in  production,
  • more reusable
  • less polluting waste,
  • require less transport

The skills required in their production are usually found locally, and their installation is often based on traditional skills and local resources. If properly identified and developed these products and services could provide much needed jobs and training opportunities, and new green enterprises.

These products are by their nature linked to diversification of agricultural production, so could have a positive effect on agricultural diversification and on biodiversity on the one hand, and on new and on diversification of rural economies on the other.

Energy efficiency and sustainable development are two of the European Union’s main priorities[1], as reflected in the Energy Performance of Buildings Directive (EPBD), the Energy Services Directive (ESD) and the Eco Design of Energy Using Products Directive (Up), and the requirement for all Member States to National Energy Efficiency Action Plans.

The availability of naturally based products and services is also an important consideration in the development of a sustainable economy and green procurement policy. Procurement by public bodies constitutes 16% of all purchases, even more in some countries (e.g. 30% in UK).

An  excellent example of the NEES approach in practise is the recent Drumalla House project in Carnlough. Co. Antrim, Northern Ireland, developed by the Oaklee Home Group, a group of social housing organisations.

The aim of this project was to design and build a new social housing development of 11 homes, to achieve Level 4 of The Code for Sustainable Homes (CSH) using renewable materials as an alternative to traditional forms of construction.  This project was a pilot project under Northern  Ireland’s  Department  of Energy and Climate Change’s  Renewable Construction Demonstrator Programme.

The project also aims  to assess the validity of this alternative building type in terms of feasibility for future developments, along with examining energy consumption and also considering tenant attitudes.

The fabric of the scheme uses timber frame construction with a hempcrete (formed from the hemp plant in combination with hydraulic lime) outer skin in place of concrete.  The CO2 absorbed in the growing of hemp more than offsets the CO2 produced in the manufacture of the binder, and use of the product will have reduced the embodied carbon dioxide in the construction of the houses by almost 40%.

For more information on NEES see our web site at www.neesonline.org .  If you want further information, contact Jose Ospina, Project Manager, NEES Project at jose@joseospina.com.

[1] See EU Wok Programme 2010