EcoHouse Risan was designed to German Passivhaus standards by Elisabeth Nöst-Kahlen an Austrian architect specialising in low-; zero-; and plus- energy buildings.
Outside walls have 20cm thermal brick between the reinforced concrete frame (legally required for this active earthquake zone), all finished with a 12cm EPS layer of insulation. We had thought to use a more environmentally friendly insulation material but costs and the local tradesmen’s inability to install anything other than EPS forced us to this material. Thermal bridging to the first floor terrace and its supporting columns is minimised by extending the insulation to cover all these surfaces. We have an integrated heating and cooling system with a 7.5kW Daikin air to-water heat pump as the energy provider. Heating is through under-floor water pipes, while cooling is via the ventilation system which also constantly recycles the internal air, drawing in about 25% external fresh air through a heat exchanger. Domestic hot water is heated by a single roof-mounted solar panel feeding a 180l tank, with auxiliary electrical heating. The whole installation was designed and installed by Ening d.o.o. of Nikšić. Windows are all triple-glazed (4-16-4-16-4), to a Rehau (German) profile manufactured and installed under licence by VH Montenegro, with external roller shutters to help heat loss/ gain. The glass has a UV value of 0.87W/m2°K. The windows were installed with an additional air-tightness tape to further reduce air leakage. The end result is a very comfortable interior environment with overall power consumption within the Passivhaus limits. In summer we have about 23° to 25° inside depending on how we feel, compared to high 30°s to 40° outside. Winter inside is 22° to 23° inside, with the outside temperature usually in the low teens, down to 5°. Frosts are (fortunately) rare, but cause havoc with the garden if they last longer than a few hours. A new building obviously allows such features to be part of the design. Retro-fitting an existing building can also provide cost-savings, especially by fitting proper insulated cladding.