Arkitekturens inverkan: jämförelse mellan tekniska- och designförändringars påverkan på energibehovet : En förskolas förändring mot passivhus

The resources of planet Earth are depleted. If everybody in the world would live the life of Swedish people a total of 3.7 Earths would be needed to replenish resources consumed. Energy is one of these resources. In Sweden more than a third of all energy is used for the housing and service sector. About 60 % of this energy is used for heating and domestic hot water. Hence, a large amount of energy can be saved by building more energy-efficient buildings, for example passive houses. There are different methods to make a building more energy efficient. The Kyoto pyramid has ranked the most important measures according to their effectiveness. The most important method is energy conservation by reducing the heat losses for the building. Different methods can be combined to reduce heat losses such as; reducing heat transmission and air leakage or changing the building’s design all of which reduces the demand of energy.The purpose of the report is to investigate methods to reduce the energy use in the design phase. The aim is to convert a conventional designed preschool into a certified passive house building. For that reason, energy reducing method that gives the biggest impact on the energy consumption has been investigated. Also, the economic benefit of building more energy efficient has been evaluated through LCC analysis.Passive house is one type of energy efficient building which has a lot of requirements to fulfill before it can be certified as a passive house. There are two existing two Passive house standards in Sweden, the international standard from Passivhausinstitut and the Swedish standard. In this report the Swedish standard is used, also known as FEBY. Passive houses require among other things good insulation of the building envelope, a high heat recovery system of the ventilation and low U-values for windows and doors.Computer simulation of the energy use in VIP Energy showed that the conventionally designed building fulfilled the requirement in the Swedish Standard BBR, but was far from fulfilling the passive house requirement. However, reducing the building heat losses toward passive house standard was not enough to reach the requirements. When the building shape was changed into a more compact (single or double story) building the requirements of a passive house was fulfilled. Although, the building with two stories are more realistic in the case studied.The biggest impact on the energy usage was the change of the building shape into a compact two story building. The individual change that made the biggest impact was when the insulation in the buildings envelope was changed (excluding doors and windows).From a life cycle perspective it is economically profitable to build more energy efficient buildings. When changes are made to the building envelope in order to reduce the energy demand, without changing the shape, the life cycle cost are reduced by 4-12 million after 50 years depending on the interest rate. The payback time of the energy saving investments is 14-17 years depending on the rate interest.It can be concluded that it is hard to build one story passive house buildings., Also, the best method to make a building more energy efficient is to reduce the U-value of the buildings envelope. Especially, if the area of the building envelope in relation to the heated floor area is large. By reducing the U-value of the building envelope savings in both energy and investment costs can be made. Even if the building shape is not changed it is more economical to build energy-efficient, assuming a service life of at least 17 years.Validerat; 20160506 (global_studentproject_submitter