A house in Romania has been built in just the sort of environment it is designed to help protect. Passive House Che is situated in a forest in the Romanian city of Suceava. In addition to a host of sustainability features, the house also has a large net suspended between floors and an indoor lawn.

Designed by Tecto Architectura, the aim of the project was to create a simple, sustainable, two-story unit that would fit into its forest surroundings. Tecto says the house was designed and built to reach the Passive House standard, which is awarded to houses that demonstrate highly efficient energy performance. The evaluation process for Passive House Che's potential certification is currently ongoing, according to Tecto.

The building covers 250 sq m (2,700 sq ft) and is built around an interior courtyard in which the lawn can be found. The "net lounge" hangs over the top of the lawn and is designed as a place for residents to relax and play. Large expanses of glazing coupled with an open plan layout are used to give the house a bright and flowing feel. Tecto suggests that certain areas in the house give the sense of being outside despite actually being inside.

The firm says that the estimated annual energy required for heating and hot water is less than 14 kWh/sq m (1.3 kWh/sq ft). High performance cellulose insulation and pressed wood fiberboard insulation are used, which are said to be non-toxic, a deterrent to rodents and resistant to mold. Vaporproof membranes, meanwhile, help to protect against condensation in the summer and facilitate drying in the winter.

The building is orientated and designed to make the most of the sun's energy for passive heating. Its green roof helps to insulate the building and is angled so as to help increase the size of the main sunlight-facing window during winter. A small gas boiler with a buffer tank is used to provide some of the energy required for the underfloor and in-wall heating, but other forms of temperature control are also employed.

The house uses an earth-to-air heat exchanger that uses the temperature of the ground to providing heating in the winter and cooling in the summer, while the living room features a biomass chimney fueled by wood chips which is connected to the buffer tank. A mechanical ventilation with heat recovery system is used to introduce fresh air to the house, which Tecto says retains 85 percent of the heat in the outgoing air.

Elsewhere, Passive House Che has a rainwater harvesting system that is connected to an underground storage tank and used to irrigate vegetation and crops. The installation of photovoltaic panels is also planned at a later date to meet some of the electricity needs of the building.

The Passive House Che project was started in 2009 and completed last year.

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