Site supervision - Foundations for Masia

SKH architects have just completed the site supervision of the first phase of a renovation project for an existing building in a rural region of Tarragona.

The existing building, shown in these photos, could not be retained during the excavation of the foundations due to the poor condition of the rammed-earth construction as well as the steep gradient of the slope to the site, which meant that the ground level had to be lowered by almost 2m at the top of the site in order for the overall roof line to be maintained according to the original volume of the masia, or farm house as dictated by the conditions of the planning permission. This deep excavation had to be carried out at closely as possible to the footprint of the ruin, and maintaining its irregular form, which can be seen in the layout of the split-level raised floor slab.

This type of floor slab or ‘forjado sanitario’, is a common construction in Spain and is preferred in general to the use of a ground-bearing floor slab. In this case we built reinforced concrete continuous footings onto which a reinforced concrete block wall was built. The prefabricated concrete beams (viguetas autorresistentes) and ceramic blocks (bovedillas) can be seen set out here spanning between the walls at 70cm centres. The space below the raised slab is then ideal for running services, is sometimes allowed to be accessible for maintenance, and is ventilated to prevent any build-up of humidity below the slab. The slab is insulated with rigid panel insulation above ground level once the final concrete pour takes place which binds these elements together and forms a level base to work from. This house will be finished in a rough lime render mixed with the local earth in order to maintain the appearance of the original building. A ground survey has already identified the areas of the site with suitable material for this purpose. The existing walls of the ‘corral’ which forms an enclosed courtyard adjacent to the house, will be retained and improved in the final landscaping phase of the build. This will give us an opportunity to try out the authentic rammed earth technique.