Passivhus : En jämförelse mellan olika byggnadstekniska lösningar för ytterväggar

Sammanfattning: This report aims to examine the design of a passive house. The design addresses the selection of material, sizing and selection of both building services systems and building technical features such as load-bearing framework and moisture control. Interior layout is designed for a family of two adults and one child. A big part of the report is devoted to an in-depth comparison of three different wall constructions of passive house standard. The structures that have been compared are a lightweight timber structure, a heavier concrete structure and a sandwich wall of the brand Weber Leca. The report covers various aspects such as air flow, wall thickness, the risks associated with the construction, U-value, thermal bridges, power consumption, price, and assembly costs. The purpose is to decide what kind of wall that would be the best option for the house. To give a satisfactory answer to this, two other questions first needed to be answered; "what is a passive house?" and "what is the difference between a passive and an ordinary house?" . It doesn´t exist a clear definition of what a passive house is, however, Forum för energieffektiva byggnader (roughly translated in to the Forum for energy efficient buildings , referred to in the text as: FEBY) has developed a specification for low energy houses. The specification contains specific numbers on how much power and energy a house can consume and still be called a passive house. The main difference between an ordinary house, and a passive house turned out to be precisely those numbers. It is worth noting that no specific requirements, except requirements for U-values of windows, is required by the design itself to be called a passive house as long as you meet the energy and power specification (Erlandsson et al., 2009). The final analysis for the three wall structures were made using a weighting table and the result was that the concrete wall was the best suited for this purpose. When the house was planned with this wall structure it manage to accomplish the FEBY requirements that have been addressed in this report and thus can be presented as "projected for Passive Houses accorded to FEBY" (Erlandsson et al., 2009).