Livscykelanalys av flerbostadshus ? energieffektiviseringsåtgärder för minskade koldioxidutsläpp
The importance of energy- and environmental issues has increased, and the work towards reducing carbon dioxide emissions plays a major part. The European Union has set up goals for the membership countries to work towards this to happen. The carbon dioxide emissions in Sweden have been reduced the last few years, but there is still a lot to do. About 30 per cent of Sweden?s carbon dioxide emissions generate from energy usage related to housing, this is why the housing sector is of interest to examine. Much of Sweden?s real estate is in need of renovation, especially many of the buildings built during the million program era between the 1960s and 1970s. When comparing the construction of the houses of the million program to the buildings built today there is a big difference between choices of materials and structural solutions. These differences affect the energy usage, and thereby the carbon dioxide emissions. A change of, for example the ventilation system, the insulation or windows might lead to energy savings and reduced carbon dioxide emissions. This report has examined a specific million program house and a specific house recently built to perform a life cycle assessment considering carbon dioxide emissions. Different improvement measures have been investigated to see how they affect the life cycle and its carbon dioxide emissions. To support this life cycle assessment a model has been created where input for different parameters such as insulation, heating and lighting can be varied. The model calculates the energy usage of the different parameters and then translates them into carbon dioxide emissions. The results show that the single parameter that reduces the energy usage the most is an installation of a ventilation system with heat recovery. In combination with a change of windows and additional insulation the transferred heat per housing area during the usage phase can be reduced with 40 per cent. Adding further actions such as changing all the lights to low-power lights, more efficient transportation and energy-saving building facilities during the design- and construction phase the total carbon dioxide emissions per living area can be reduced with 20-30 per cent from the whole life cycle. Throughout the preparation of the report there has been a focus on the difficulties of making general life cycle assessments considering carbon dioxide emissions in apartment buildings. There are many aspects where there are big variations and normally as many opinions on how to implement them. This means that it is important to examine every single house and its specific qualities to find out what kind of influence the house has on the environment and what measures of improvement that are possible.