Christian Mattsson

Title of project: Reduction of the costs of water damage in buildings through a holistic perspective on technology, users and risks

A large amount of water damage cases and resources are annually reported and spent on water damage in Sweden from cases occurring in buildings from building services such as tap water-, sewage, heating systems, household appliances such as refrigerators, freezers and dishwashers and inadequate waterproof membranes in wet rooms. These water damage cases in buildings cause several problems in the built environment regarding economic, environmental, and social aspects of sustainability such as unhealthy indoor environments due to higher levels of moisture, mold growth, and redundant usage of building materials and resources in reparations and renovations of water damaged constructions, immense amounts of monetary resources spent annually by both residents, building owners and insurance companies to restore the buildings to their designed purpose.

This project aimed to reduce water damage occurrence and costs in buildings by outlining a holistic approach to the aspects of sustainability, occurrence, costs and solutions. Using qualitative and quantitative methods to analyze the state-of-the-art water damage research field, this project conducted several analyses to determine the occurrence, costs and solutions of water damage in the buildings. To reduce the impact and effects of water damage in buildings this project used empirical statistical data, parametric analysis, and a holistic approach regarding factors such as building purpose/type, extent of occurrence and causes, effects of the damage, different stakeholders and different solutions. A model was proposed regarding key figures, water damage causes, age distribution of reported damage cases, and estimated repair costs depending on the water damage cause and origin, to consider during the different phases, design, construction and operation, of the building.

The results of the project found that there exists a gap in the research and data collection of water damage occurrence, costs and consequences in buildings such as multi-family and non-residential buildings. The research conducted often includes the studied type of water damage cases in this project; building service systems, appliances and waterproof membranes, within the fields of building pathology and building defects but does not explicitly study the causes, associated costs and occurrence from different water supply systems and different origins within the building. The consequences of water damage from building services and installations, such as environmental and social impact are not often regarded.

The associated costs of water damage for the studied part of the building stock, were calculated to amount to approximately 1.1 billion € per year (12.6 billion SEK) including repairs of water-damaged buildings, single-, multi-, and public buildings, and insurance costs covered by the residents, such as deductible and age reduction costs. Solutions identified, that could be a part of the solution to reduce the occurrence, cost and consequences of water damage, were both passive and active technical solutions together with structures and information regarding the management and operation during the different phases of the building life cycle. The model presented causes and water damage cases, reported by the insurance industry, with the costliest repairs occurring due to corrosion, age/wear, and freezing damage, followed by faulty waterproof membranes and connection of membranes to drains and then refrigerators/freezers and dishwashers. Moreover, the expected time before water damage was reported was found to be most frequent in the first 10-year period after installation for several water damage causes reported in single-family buildings.