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Modern Earth Construction in Scotland - with comparison and reference to earth construction in Germany (summary of Debbie Hey’s presentation on completing her tour which was funded by the Krystyna Johnson Student Travel Award scheme in 2003) Introduction Globally, the introduction of new building materials such as steel and concrete was a critical turning point in the use of earth throughout the world, which affected earth construction in both Scotland and Germany in different ways. Whereas Scotland lost its earth construction tradition completely, Germany persisted through both World Wars due to shortages of the new materials. Present day comparison of Germanys and Scotland’s earth building industry shows that Germany has advanced further as a result of this continuity and overcome many of the perceived barriers of earth as a modern material. Although Scotland has started to reintroduce earth building into the construction industry at present it is still quite limited. There are a number of obstacles that need to be addressed before Scotland can look forward to a thriving earth construction industry. Information and Skills The Scottish Construction Industry is very poorly regulated at present which in turn has led to a relatively unskilled workforce. Unlike its German counterpart, it is also a difficult vehicle through which to disperse new information. Earth building practices in Europe have suffered due to the practical skills and knowledge of techniques being forgotten over the last century. In order to re-establish earth building skills and to teach the knowledge set out in the German standards the Dachverband-Lehm is piloting a vocational training course in certain areas of Germany, entitled “Specialist in Building with Earth”. It is hoped that this trial course will help establish the field of earth building as a separate building trade, accepted by the Chamber of Crafts, and with equal status to other building trades. Scotland is a long way from this level of support with still very few contractors aware of, and competent in earthen materials. Standards Help and advice from German practitioners and guidance have helped pioneering Scottish Architects using earth construction through the planning and building warrant applications, but if Scotland is to become an earth building nation once again it must produce its own earth building standards. In 1998, the Dachverband-Lehm (www.dachverband-lehm.de) published the first technical standards for building with earth in Europe. Although at present no Scottish earth building standards exist, in recent months the consultancy In Situ Rammed Earth Co. together with the University of Bath have won a DTI bid to produce a Code of Practice for earth building in Britain. Techniques and Products Due to the introduction of earth building standards in Germany and much needed research into traditional earth building, many different techniques and products have been effectively industrialized making the industry as a whole more competitive. German earth building products are used all over the (developed) world, while at present, most earth building products are imported into Scotland. To compete as a sustainable building material in Scotland on any scale the industry must also start to produce its own manufactured earth products. This is beginning with Errol Bricks and the work they are doing with Arc Architects on the wider scale production of earth bricks. Interestingly, while solid earth bricks remain the dominant earth product in Germany, current building regulations require higher thermal insulation in all external walls, so wooden skeleton structures with clay and straw infill panels have become the most popular earth building technique due to their improved thermal insulation properties. The technique is best suited to self build projects due to its lack of specialist equipment and inexpensive building materials.
Perceptual Barriers The questionnaire used to elicit information about perceptions in Scotland about earth building clearly demonstrated the cultural and educational barriers identified by participants, but also showed that for all four groups questioned, Academics, Professionals, Students and General Public, a different approach would be required in order to address these prejudices and pre-conceptions. Lack of Awareness of the Technique The most significant barrier that needs to be overcome for earth construction to become a recognised building technique in Scotland is the lack of people knowing what earth construction is, or that it even exists. A combination of demonstration projects and the use of the media, for example TV shows, will help the building material to gain creditability allowing it to be used more widely on large scale projects. Prejudices against Earth as a Material A second significant barrier is the general public’s perception that the damp Scottish climate will affect the earth structure, associating the resulting space with cold damp areas, bugs and rodent infestation. There is also an association of earth buildings with “mud huts” and buildings of the past, no longer suitable for modern needs. If the general public is not kept informed of the development then there is a danger that they may be left behind while only a small number of enthusiasts will know about it and want to know more. This issue is also recognized in Germany. Real Limitations Quite apart from the prejudices around, Tom Morton’s research (Arc Architects) has suggested that one of the major realities of using earth construction in modern building is it can only be used internally or only externally if protected by a rain screen. Another reality is that fashion drives the choice of material used for construction in Scotland. This has meant that the demonstration projects have had to make a statement and show the earth within the walls as part of the aesthetics to allow it to become more established and a recognised building material. In the long term it is hoped that earth products will be like any other building materials; shown or hidden within the fabric makeup as required. Another problem is one of cost and economies of scale. Until earth construction is a more common construction in the UK, the costs of the technique, products and materials is likely to be prohibitive to many. The “drying out” period associated with several of the earth techniques, and the fact that construction processes can be time consuming and labour intensive all increase the overall budget of building with earth. Yet despite these potential hurdles, it is apparent (to some) that the ‘normal’ materials used on conventional buildings have serious environmental drawbacks. New low energy materials need to be found with good ecological properties. Earth is the perfect low energy material. There are two main approaches towards earth construction and its future in both Scotland and Germany. Firstly the use of prefabricated, industrialised techniques, and secondly the use of earth as a modern craft technique. Craft based products are more appropriate for one-off buildings, but if earth building is to become efficient, functional and integrated into modern society it must become standardised, prefabricated and accredited without losing its natural beauty as a product. There is a range of earth building techniques that may be used for construction. The most appropriate for Scotland at present appears to be the use of unfired earth bricks which Tom Morton and Arc are currently researching. This technique is efficient, functional and integrates well with the modern construction industry as it uses little more than existing brick-laying skills. Learning from Germany The Germans have shown us that earth construction is possible in modern day society. Although they are still learning valuable lessons about earth products, regulations and fast and effective techniques, they have overcome many of the perceived barriers associated with the material. Many of the German delegates at the Modern Earth Building Conference held in Berlin were still worried that earth building needed to gain more credibility as a building material, but this will only come with time and more demonstration buildings. Although Scotland is still in the early stages of introducing earth construction, German experience and techniques can be used as a learning tool, and despite pre-conceptions it is clear that those interviewed are open to novel building techniques, which is a hopeful sign for the future of earth construction in Scotland. Thanks Many thanks goes to the Scottish Ecological Design Association (SEDA) and Jim Johnson for the kind award of the Krystyna Johnston Travel Scholarship which allowed me to undertake a field trip to visit many of the British and German examples of modern day earth construction. The award also allowed me to attend the Modern Earth Building Conference in Berlin in October 2003, both of which were invaluable experiences which allowed me to more fully develop the dissertation. |
