Foto: Vojta Herout, www.vojtaherout.com
Healthy House Made of Natural Materials
A young family of five have fulfilled their dream of living in harmony with nature. Now their home is a passive house on a plateau with a wide view of the valley and a terrace covered with vineyards, which manages water in the landscape very economically thanks to a root treatment plant, a rainwater storage tank and a green roof. Thanks to these measures, it is possible to retain water in a place suffering from drought. In the summer months, the surroundings of the house and the house itself are cooled by a green roof. In addition, the house is built of easily recyclable materials and plays with natural heating thanks to the windows facing southwest and photovoltaics on the roof.
The Adaptation Journey
The positive impact
The goal of the construction of a passive family house was to create a family house with a pleasant environment that would satisfy the needs of the owners and at the same time be in harmony with nature. Only natural and local materials were used for the construction. The house has the characteristics of nearly zero-energy buildings with a minimal ecological footprint and aims at self-sufficiency.
The location on the hill suffers from drought, and therefore the design of the house tries to solve this risk with individual measures, such as rainwater collecting, purification of black and gray water in a root treatment plant and planting the roof with vegetation.
Another risk is high summer temperatures, which are solved by a green roof, vines and wooden slats around the perimeter of the house serving as shading.
How does it work?
Drought in that locality is solved by several measures. The area of the sloping roofs is planted with stonecrops, which retain water and support the cooling of the house and its surroundings. The flat roof surfaces are used for quick collection of rainfall, and therefore the owners treated them only with a layer of gravel, so that it was possible to collect even short ten-minute summer showers to use it to water the growing vegetables.
All wastewater from the house is handled by a root treatment plant. In the first stage, it flows through a four-chamber septic tank and continues horizontally and vertically through the root system into a tank for both the rainwater and the wastewater. The tank has a volume of 5 cubic meters.
Warmth of home
The temperature and humidity inside the house are balanced by internal clay plaster. The house is shaded by wooden slats placed in several parts around the house. Thanks to the orientation and size of the windows, the demands on heating are reduced in winter, and in summer the pergola covered with vines provides enough shade for the house not to overheat. Until the vines are big enough, the windows will be protected by simple external blinds.
The owners source the heat for the house and water mainly from renewable sources from the sun directly from the photovoltaics located on the roof and indirectly by burning wood in a small stove. They need only 1 cubic meter of wood per year. Rarely, when water needs to be heated quickly, they use energy from Nano energies. A healthy indoor environment is ensured by air exchange with heat recovery controlled by a CO2 sensor according to current needs.
In the spirit of voluntary simplicity, the owners decided to get only a one-story house with a built-up area of 120 square meters and a usable area of 97 square meters. They used easily recyclable materials for the construction, such as local wood for construction, local clay for internal plaster and blown cellulose for thermal insulation.
Thanks to the individual measures, it is possible to retain water around the house, reduce drinking water consumption, increase biodiversity thanks to the green roof and permaculture garden, and thanks to low energy performance and natural and easily degradable materials used, the ecological footprint of the house is generally reduced.
The plot where the family house now stands was originally a non-building plot with high-pressure gas pipes, so a big part of the land could not be built up. To start the construction, it was necessary to change the urban plan and finish the zoning procedure for the root treatment plant. These necessary steps took eight years, but the building itself took only a few months.
Operation and maintenance
Maintenance-free vegetation roof requires minimal maintenance costs. The larch cladding of the house is also maintenance-free, as it does not need painting thanks to natural oils. It is needed to drain the root treatment plant and remove a minimum amount of sludge once a year, which the owners of the house can do on their own.
Why was the measure chosen?
At the beginning, the owners considered building the house themselves and using straw bales, but they rejected this option due to the time and effort it needs. Originally, they wanted to use a composting toilet, but this proved incompatible with a root treatment plant, unnecessarily expensive and technically complicated.
During the preparation of the project, the owners considered larger windows. However, it would be neither practical nor pleasant with regard to thermal comfort and privacy.
In the house there are conduits for distribution of service water from a sump for flushing toilets. At the moment, however, the capacity of the sump is not sufficient. They use all the water for irrigation. In the future, they plan to increase the volume of water collected and use it as service water in the house.
Obstacles and challenges
The biggest obstacle was the time-consuming process of approval of the construction. The delay in the construction was also caused by the application for a subsidy.
Operation and maintenance
The air conditioning can be heard only a little, but a certain sound discomfort is created by the gaps under the door, where the exhaust air is being sucked in.
Normal operation, such as cooking or a hot shower, has a great influence on the heating of the house. During cooking, the temperature inside the house can rise by two degrees Celsius on a summer day.
How much did it cost?
The total cost of building the house, including the root treatment plant, was around 5 million crowns (189,226 EUR).
Funding for construction came from the investor's private sources and from the New Green Savings Programme grant.
Expected service life is 100 years.
Family and apartment houses Water purification and recycling Use of rainwater Heating Green roof Shading Biodiversity Heat waves and thermal island Lack of water and drought Green energy