Villa Skoghem is a two-storey passive house built in Brattland, Sweden designed by architect David Fredlund and builder Jim Gällros. The owner’s ambition for the house is to meet both International (PHI) and Swedish passive house standards (FEBY – Forum for energy efficient buildings). The house is designed to absorb solar heat gains from windows and heat generated by the living residents’ bodies and home appliances. 30 candles are all the house needs to warm up on the coldest day.
The house has two storeys with a basement that makes up the total treated floor area of 204 m2. The basement has heated space (the technical room) and cold area (storages and garage). The walls separating these two area are insulated as well even though they are inside the house. The concrete floor is cut to make a few centimeters gap between the heated and unheated space to prevent ‘cold bridge’. The entrance on the ground floor has a windbreak room at the entrance to prevent heat losses from opening the house main door.
Although it is not a passive house requirement, the owners decided to use natural materials to create harmony between the house and the surrounding nature, as well as having minimal impact to the environment. Except for the concrete floor and walls underground, the above ground structure is mainly wooden and all materials are PVC free. CLT spruce planks and plywoods are the main selection for inside wall, ceilings, floors while Thermowood are used for the outside of the house. Pavatex wood fiber insulation and blown-in cellulose insulation prevent the house from heat losses. For the base floor insulation, EPS was mounted under the basement concrete floor.
Heating is provided both through ventilation and floor heating. The heat is recovered from extract air to supply air in Genvex Eco 375 unit with the recovery rate of 83%. As common practices, supply ducts are insulated and extract ducts are stacked in the wall insulation. In addition, ground heat is collected from 300m of pipes running horizontally underground as an additional heat source for the 3kw heat pump for floor heating and domestic hot water. Since the house have floor heating, intermediate floors are insulated as well.
Annual heating demand (calculated): 20 kWh/m2.a
Airtightness: n50 = 0,2