GotlandsHem offers a various types of properties, from medieval buildings in the inner city of Visby to modern terrace houses. In 2010 the company's first low energy houses were inagurated in neighbourhood Sjöliljan in northern Visby.
Technical solutions; low-energy houses
Sjöliljan consist of three five-story houses. The houses are round in order to have as little outer area as possible in relation to the volume of the building. Solar heating with supply from district heating provide hot water and, when the outdoor temperature is very low, also preheating of supply air to the houses. The walls are super insulated, the windows are leak-proof and the heat in the exhaust air is recycled to reduce the amount of thermal energy and the high density design minimizes heat emission. The heat generated by the residents, household appliances and lighting are to be enough most of the year.
Sjöliljan. The houses are so-called low energy, which means they are built without traditional heating systems.
Comparison of different kind of houses:
- Sjöliljan; installed effect 12 W/m2; energy supply 50 kWh/m2 and year.
- Passive house; max installed effect 10 W/m2, energy need appr. 45 kWh/m2 and year
- Normal house, new production; ca 50 W/m2 installed effect, 110 kWh/m2 and year.
Sjöliljan’s slightly higher energy demand compared to passive house standards depends on larger window areas. The houses are extremely dense, their maximum air leakage is 0,3 l /s and m2.
Environment actions and results at GotlandsHem as a whole
- 20% less heating energy
- 38% less transport fuel
- 12% less water use
- Every household can sort out their waste
- No fossil fuels for heating
Community heating, mainly bio fuelled, heats 97% of GotlandsHem’s properties. All fossil fuels for heating has been replaced by bio fuels. New apartments are equipped by systems for individual monitoring of heat and water consumption in every single apartment.
Solar heating is installed at the Terra Nova outdoor-bath in Visby, and on apartment blocks in Klintehamn and in Fårösund.
- Adjustments of heating system, circulators and ventilation systems
- Attic insulation controlled and completed
- Remaining oil boilers are replaced by wood pellets boiler
- Education of staff
Result: From 1996 until 2008, the need of heating was reduced by 30%, from 196 to 140 kWh/m2 a year, but the long and cold winters 2009 and 2010 led to an average of 157 kWh/m2 a year.
Transports, lawn mowing and snow removal
GotlandsHem is geographically widespread and also consist of large lawns, flowerbeds and parking lots. To reduce the need of fossil fuels for transports, lawn mowing and snow removal parts of the vehicle fleet is renewed. Older vehicles are replaced by more fuel-effective and environment labelled vehicles.
Result: 38% reduction of the fuel consumption since 2000.
The main part of the household waste can be recycled. All residents have access to nearby recycling stations where they can sort out compost, newspapers and packages of paper, plastic, metal, batteries and light bulbs.
GotlandsHem’s residents use about 600 000 cubic meter per year. To reduce the consumption of water old toilets and taps are exchanged. A new toilet saves 6–8 litres of water per flush compared to an old one. Water saving installations also saves hot water and are thereby also energy efficient.
Result: 12% reduction of the water consumption since 2006.
Since 2002 GotlandsHem buy eco labelled electricity, which is electricity produced from renewable energy sources. The electricity consumption is also reduced by replacement of old laundry equipment, transition to low energy light bulbs and adjustment of the ventilation system.