
![]() Previous Winners and FinalistsStraw-bale Housing in the Sieben Linden Ecovillage
Aims and Objectives
Project Description
Project context
This project was established as an intentional community, one of its primary purposes being to develop better ways in which community cooperation and participation can be encouraged and supported. Sophisticated methods of cooperative decision-taking have been established. A move away from 100 per cent consensus decision-taking has been necessary as the community has grown larger. Living and working in a community provides countless possibilities for individual and cooperative empowerment and a rich social life. Sharing communally-used facilities helps to promote contact and cooperation between people of different ages, skills, education and origin. Emphasis is put upon building communal structures before building private accommodation. Members of the project are encouraged to become involved in local politics. The community as a whole supports these activities, encouraging a greater level of action and involvement. The weight of this participation and increased voice has resulted in successful outcomes campaigning on local issues.
The land itself was very cheap to buy as it is in an area of low demand. Forty-two hectares and two old buildings were purchased for US$ 284,000. The three houses built to date differ greatly in cost as they have used varying amounts of self-help labour. The Villa Strohbund cost less than US$ 323 per m2 compared to US$ 1,670 per m2 for Strohpolis and US$ 1,613 per m2for Brunnenwiese. The costs are equivalent to standard, conventional, construction costs in Germany, which are between US$ 1,420 – US$ 1,940 per m2. However, the money paid for straw-bale construction goes to the local agricultural industry and to local workers, including some residents. This has given a much needed boost to the local economy. The costs have been met by the future residents themselves and through bank loans. Residents invested their own funds in the cooperative and these funds will be returned to them if, and when, they leave. Investments have also been made in the form of residents contributing their own labour to the construction of the buildings, and receiving compensation for doing so. Impact
Innovative Aspects
Environmental Sustainability
The project makes use of environmentally-sustainable materials that are locally sourced, such as straw, clay, timber, and glass. Using locally-available materials helps to reduce production and transportation costs. The production of an average family house using straw-bale saves 25 tons of CO2 when compared to an equivalent building insulated with mineral wool. The design also seeks to minimise construction waste and the houses can eventually be recycled. The materials are absorbed back into the natural cycle without leaving polluting residues.
Research studies undertaken by the University of Kassell in 2002 showed that the CO2 emissions per capita were 72 per cent lower in Sieben Linden than the average German household. Especially large reductions were achieved for space heating, where the community recorded reductions of 90 per cent compared to the national average.
The houses need only 50kWh/m² or less per year and comply with the German definition of low-energy housing. All electricity used is produced using photovoltaics (PV). Drinking water comes from a well in the village and waste water is cleaned by reed beds before being used for irrigation in the vegetable gardens and orchards. Dry composting toilets reduce the level of water consumption. Fuel wood from local forests is used for heating and water is warmed using solar energy. The project avoids all building materials that have a large negative impact on the environment, for example plastics. The area that can be built on is limited to 16m² per person, to keep the amount of soil that is covered as small as possible, and maximising the ground area available for agriculture and other activities. Financial Sustainability
Sieben Linden is not reliant on external funding sources. Self-help and self-reliance are encouraged rather than dependence on external employment, materials and energy.
The money that is paid for straw-bale construction is not given to large corporations or paid to cover transportation costs, but is rather invested in the local agricultural economy and in local workers. Although the costs for straw-bale construction in Germany are approximately equivalent to conventional construction, most of the cost is for the wages of those who build and plaster the walls, thereby reinforcing the local economy. The locally-available, low-cost materials can be used in the building process by unskilled workers and this enables households on low incomes to provide themselves with good quality homes with reduced ongoing water and energy costs. The current recommended straw-bale building system of FASBA is particularly suitable for do-it-yourself building as it involves an infill rather than a load-bearing system. The maintenance of the buildings also uses low-cost materials and does not require high skill levels. Low energy consumption reduces the risks of being exposed to rising energy costs as world energy supplies become increasingly scarce. Social Sustainability
Sieben Linden has been established as an example of communal living. One of its priorities has been to develop better ways for communities to live and work together. Based on principles of self-determination, all decisions made throughout the project are a result of community participation.
Living in different ‘neighbourhoods’ has enabled diverse approaches to communal living to be formulated, explored and applied. Some groups share their entire economic resources, and others live following more conventional cooperative approaches. Within the founding principles of self-sustainability and self-determination, a variety of approaches is encouraged. Living and working in a community offers many opportunities for individual or cooperative empowerment. Social integration is a natural consequence of community living. Rich social lives emerge, and the sharing of communal facilities promotes contact, cooperation and integration between people of varying education, skills and origins.
The building process has further encouraged people to engage with and depend upon each other, and to learn handicrafts and skills enabling them to fulfil their own basic needs. An emphasis on building communal structures before building private accommodation has further enhanced the community cohesion. The use of natural materials for construction, including straw and the thick clay plastering, provides healthy, comfortable living environments.
The community works actively to support the involvement of its members in local politics. A significant impact has been made, particularly in the area of maintaining local community facilities and services, and also in various lobbying campaigns, an example of which has been the successful protest against genetically modified food. Barriers
Lessons Learned
Evaluation
A simple footprint analysis was carried out to show that the whole construction process needed less than five per cent of the average energy input compared to standard ecological house building. A more detailed footprint analysis is currently being undertaken by the Technical University of Berlin. Monitoring of energy usage is also regularly carried out.
Transfer
FASBA promotes the construction methods regionally, nationally and internationally and organises internships on the straw-bale construction sites. The project has been enlarged and one of the newly- constructed buildings is to be finished in 2007 accommodating 20 people. Two others will be finished at the end of 2007 for 15 people to start living in them.
Local architects have shown an interest in the technology and are looking to develop similar buildings locally. The number of straw-bale houses has doubled within the last 16 months and now stands at 50. Three schools are currently being designed for construction using straw bales. Funding for straw-bale construction is now available from the German Ministry of Agriculture. The change of the building regulations to permit straw-bale construction has had a positive influence around the world, particularly as Germany is well known for its strict building codes. Networking is carried out with similar projects that are being established in the USA, Denmark, Scotland, Estonia and Croatia. Since 2002 regular events have been held with an international emphasis in order to share the experience of straw-bale construction more widely. Requests for advice and consultancy services are received from all over Europe. Contact Point
Ms Elke Wiegand
Director Freundeskreis Freundeskreis Oekodorf e.V. Sieben Linden 1 DE 38486 Bandau Poppau Germany
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