For all of us born after the 1970s, the idea that we are living in a planet with limited resources is a fact that has included words like sustainability, recycling and renewables into our daily vocabulary. Energy efficiency fits into this set of ideas, and although we are very conscious of the urgency of reducing energy consumption in all new consumables (cars, appliances, lightbulbs…), it has not permeate that one of the biggest energy loses happens in our own homes. In Spain around 25% of the total electric energy demand1 is for residential housing, and through various policies, an energy saving of 27% has been planned for by the Horizon 2020.
There are many ways to address energy efficiency in a building, like considering the location and surroundings, external envelop colors, ventilation, window location etc. However, building materials and insulations have a very important part to play, and here is where timber 3D modular housing can provide a significant quality step, both in terms of material, but also prefabrication.
Timber is by far the most sustainable building material, with the lowest energy consumption during its lifecycle and naturally renewable. While other materials release C02 to the atmosphere during their production, timber sequesters and “locks” it away, releasing oxygen instead. There are many studies2 now that compare the energy required to get different building materials to site, from which the conclusion that using massive timber elements for building could achieve negative net CO2 emissions.
CLT Cross laminated products are massive solid timber panels that provide excellent weight to span ratios and high strength. After being developed in central Europe during the 90s, by 2008 the tallest habitable timber building in the world3 was built in London, starting a market revolution that has spread CLT all over Europe, as well as USA, Canada4, Australia5 and New Zealand. Nowadays, over 5 story high timber buildings are very common, the typical middle city height in Spain, for example.
CLT panels use formaldehyde free glue and approach a zero waste system, where left over and cut outs are given other uses, from furniture, other buildings or biomass.
At Egoin we have discovered that CLT is an ideal material for modular units, which, leaving the factory fully fitted, can be assembled on site at incredible speeds (80% quicker than traditional concrete frame), creating for example, very few inconveniences for neighboring properties. Abadiño´s nursery6, Belambra Capbreton camping resort7, or, more recently and in height, Biarritz Parme, photos below.
Taking advantage of the good inherent insulation properties of timber (0,13 W/(m2K)), the natural air tightness of a glued system and providing good insulation and windows, new thermal regulation values are easily achievable, and even surpassed up to passivhaus standards, for example, our Casa Vita Project8, which also obtained the Minergie certificate.
The construction industry needs to address energy efficiency as serious matter in the next few decades to reduce the amount of pollution and resources that it currently wastes. It´s our common global responsibility to do so and CLT prefabricated modules have proved a cost efficient, versatile and modern solution.
1.- Proyecto Sech-Spahousec, IDAE, 16 de Julio 2011.