Reliable methods are needed for classifying the robustness of buildings and building materials for many reasons, including ensuring that constructions can withstand the climate conditions resulting from global warming, which might be more severe than was assumed in an existing building’s design. Evaluating the robustness of buildings is also important for reducing process-induced building defects. We describe and demonstrate a flexible framework for classifying the robustness of building materials, building assemblies, and whole buildings that incorporates climate and service life considerations.

The main purpose of this book, Hygrothermal, Building Pathology and Durability, is to provide a collection of recent research works to contribute to the systematization and dissemination of knowledge related to construction pathology, hygrothermal behaviour of buildings, durability and diagnostic techniques and, simultaneously, to show the most recent advances in this domain. It includes a set of new developments in the field of building physics and hygrothermal behaviour, durability approach for historical and old buildings and building pathology vs. durability. The book is divided in several chapters that are a resume of the current state of knowledge for benefit of professional colleagues, scientists, students, practitioners, lecturers and other interested parties to network.

A large amount of the buildings in Norway is from the 1970s. Many of these buildings have timber frame walls and are now ready to be retrofitted. Application of vacuum insulation panels (VIPs) can make it easier to improve the thermal insulation in building walls with a minimal additional thickness. Retrofitting of buildings using VIPs may therefore be done without large changes to the building, e.g. extension of the roof protruding and fitting of windows. Additionally, U-values low enough to fulfil passive house standars or zero energy building requirements may be achieved. Thus, contribute to a reduction of the energy use and CO2 emissions within the building sector. This work investigates two different ways of retrofitting timber frame walls, one with VIPs on the cold side and one with VIPs on the warm side. A wall module containing four different fields is built and tested between two climate rooms with indoor and outdoor climate, respectively. The module consists of one reference field representing a timber frame wall built according to regulations in the 1970s in Norway, and three fields representing different ways of improving the thermal insulation of the reference field with VIPs. As VIP is a vapour tight barrier, the fields are tested with respect to condensation risk. A new sensor for measuring surface condensation called the wetness sensor is introduced. The results of the experiment show that this method of retrofitting may be acceptable in certain structures within limited climate zones, humidity classes, and building envelopes.