Assessing the Passive House regulations for future climate conditions in Swedish single family residential building

Global warming is a very much researched and debated topic in the current period as we can see the effects around us. The literature and discussions have pointed to a surface temperature rise of up to 10°C at the poles and around 4°C-7°C around the equator. The effect is more in the northern hemisphere than in southern hemisphere of our planet Earth. The effects of the warming of our environment on the buildings and the future weather patterns are being researched in many countries. This master thesis work assesses one such scenario of the effects of climate change, projected future weather patterns on the energy consumption for heating and cooling, moisture performance and mould growth of the external wall and external roof layers in four cities of Sweden namely Lulea, Stockholm, Gothenburg and Lund. The research for energy consumption was carried out with future climate data derived from the GCM’s and RCM’s for Extremely cold year, extremely warm year and typical downscaled year; the results from these three scenarios were clubbed together to get combined yearly energy consumption which can be comparable to the reference year data. Moisture performance was carried out only for Gothenburg using CNRM and IPSL climate data to show the effects of climate change and warming of the environment on the building outer protective layers. The results clearly show a considerably increased cooling load and decrease in heating loads in four Swedish cities over a period of next 80 years. The results for moisture performance and mould growth also shows an increase in relative humidity, temperature and water content in layers. Mould growth calculations also show an increased activity over next 80 to 100 years.Global warming is a very much researched and debated topic in the current period as we can see the effects around us. The literature and discussions have pointed to a surface temperature rise of up to 10°C at the poles and around 4°C-7°C around the equator. The effect is more in the northern hemisphere than in southern hemisphere of our planet Earth. The effects of the warming of our environment on the buildings and the future weather patterns are being researched in many countries. This master thesis work assesses one such scenario of the effects of climate change, projected future weather patterns on the energy consumption for heating and cooling, moisture performance and mould growth of the external wall and external roof layers in four cities of Sweden namely Lulea, Stockholm, Gothenburg and Lund. The research for energy consumption was carried out with future climate data derived from the GCM’s and RCM’s for Extremely cold year, extremely warm year and typical downscaled year; the results from these three scenarios were clubbed together to get combined yearly energy consumption which can be comparable to the reference year data. Moisture performance was carried out only for Gothenburg using CNRM and IPSL climate data to show the effects of climate change and warming of the environment on the building outer protective layers. The results clearly show a considerably increased cooling load and decrease in heating loads in four Swedish cities over a period of next 80 years. The results for moisture performance and mould growth also shows an increase in relative humidity, temperature and water content in layers. Mould growth calculations also show an increased activity over next 80 to 100 years. Results from the simulation of typical passive house shows the current regulations for Zone III need to be worked on and possibly a reduction in heating demand and a limit on cooling demand can be introduced for future scenarios. For Zone II around the region of Gothenburg cooling demand limitations can be introduced in the regulations. For Zone II around the region of Stockholm both heating and cooling demand limitations can be introduced. For Zone I, around the region of Lulea, the heating demands in future scenarios is matching the current regulations and the cooling demand is minimal, therefore there is no need to change any limitations and current criteria can be applicable for future scenarios. It can be concluded that the heating demand in the typical two stories single family passive house is going to decrease and cooling demand is going to increase in all the four studied cities of Sweden. Overheating periods in the passive houses are also going to increase, which corresponds to higher cooling demands. Moisture related problems such as mould and rot growth is going to increase due to warmer and wetter climatic conditions. Attics and roof elements are more susceptible to mould damage than wall. It was also seen that concrete and brick were more resilient and protect the roof and wall from moisture related problems. Some of the methodologies which can be used to reduce over heating periods are solar shading devices, addition of ventilators for natural ventilation during warm periods, using phase change materials in the construction