Hi. We have designed and erected many timber frame houses in the EU including Spain without any problems as MMC (Modern Methods of Construction) have to meet exactly the same codes as any traditional building. There is a distinct difference between a wood prefab building and an engineered timber frame house, in that a timber frame house will be designed under the Eurocodes and meet and beat both the very demanding UK Building Regulations and the Spanish codigo internacional de la construccion. All timber frame buildings have site specific structural calculations prepared to EU standards and are classed as mainstream buildings. Spanish buildings and MMC are light years apart with timber frame having an ecological pedigree second to none with very low carbon emission and passage of sound levels. They are fast to build and much cheaper to build and maintain for the whole of life. While this method of construction is very popular globally as more than 70% of all low-level (up to 7 stories) new-builds are timber frame, Iberia often does not fully understand the concept. All EEC compliant buildings are mortgageable.