Enjoy a centenary house with the maximum comfort and minimum energy cost. The challenge was to refurbish a house built in 1918 maintaining both the original volume and façade whilst improving the thermal and acoustic comfort. The construction systems and materials used have made possible not only to achieve the goal but also to lower the energy demand from 171 kWh/m2a to 17 kWh/m2a (known as a 10 factor rehabilitation); transforming a traditional existing building into a Passive House in only 120 days.
The three main difficulties were: the north-east orientation of the row house, the limited budget and the urgency of the clients to move in.
The main operation was to redesign the section in order to re-orientate the house. The new skylight permits the solar passive gain in winter, the cross natural ventilation in summer, fills the centre of the house with natural light and provides a proper orientation to the solar panels. A new big opening stretches the tiny interior towards the garden.
A prefabricated dry construction system was chosen to achieve the maximum precision and shorten the building process. The different elements (roof, façade, mezzanine, staircase, skylight) were designed like Meccano pieces to be manufactured with a numerical control system and afterwards assembled in site. The whole roof was mounted in few hours, the same as the other elements.
In addition to such excellent energetic performance, bio-construction materials were used in order to reduce the environmental impact. Therefore, the new roof and façade were built out of a structural wood-frame construction system using OSB panels and natural sheep wool and wood-fibre boards for insulation. The ventilated façade is finished with planks of natural larch wood and the roof with heat-treated pine wood. In the interior, the mezzanine, kitchen and cupboards are entirely made of 3 Ply Shuttering panels and linoleum for the flooring. The house is provided with solar panels for water heating and a high energy efficient device for ventilation.