The Dilemmas of Choosing a Suitable Technology for Low Energy and Passive Houses in the Context of their Overheating Issues

In compliance with European Union directives, numerous countries are introducing increasingly stricter legal limits on the estimated energy consumption of newly designed residential buildings. However, the fact, that regulations and designers' efforts are focused on decreasing energy consumption (and consequently carbon dioxide emissions) only at the post-occupancy stage, may lead to a significant increase in the carbon footprint of the buildings during their entire life cycle. A frequent criticism levelled at low-energy and passive buildings is that they are susceptible to the phenomenon of overheating. The reduction of overheating through the choice of "massive" technologies, materials with high thermal capacity as well as a high heat dispersion coefficient, stands in opposition to the requirement to choose the technologies that ensure a low ecological footprint (i.e. timber frame technologies). The development of a tool facilitating decision making in this issue seems to be a challenge. Life Cycle Assessment (LCA) is a well-known, optimal method for forecasting buildings' carbon footprint, however, it is an expensive and time-consuming method. Life Cycle Assessment is a method dedicated to large investments. In practice, such analysis are not carried out for residential buildings. The purpose of this paper is to analyse the foregoing problem on the example of detached single-family houses and to propose a method and tool that can assist architectural design in this regard.