Building for a future climate - focus on moisture safety

Scenarios currently predicted for Sweden’s future climate entail increased risks of moisture damage in our buildings if we do not adapt them to such changes. It is especially important to consider the risks associated with the future climate in regard to new construction and renovations to avoid costly additions and alterations in the future.

This project presents some examples of adaptations available today; they provide an insight into the possible means of adapting properties currently available to the construction and property sector. There is also considerable potential for innovation and further development in the ways buildings can be adapted and the project highlights some areas where this will probably be necessary.

The adaptations addressed in this preliminary study have been grouped into the areas flooding, increased temperature, humidity and driving rain. The conclusion is that the construction sector has advanced to different extents within the three areas of adaptation addressed by this preliminary study, and that potential remains for further adaptations in each of these areas.

• In the case of flooding, which is also the most prominent area and where events clearly show the need for adaptation, there is often an awareness of the problem, and there are examples of technical measures that can be taken. However, it is unclear whether these measures have been put into practice to a sufficient extent. Here too, there is likely to be a potential for further development of solutions to improve moisture safety in buildings.
• As for temperature and humidity, we note that the construction sector already faces challenges in the construction of moisture safe buildings and the sector is working to solve problem areas such as cold attics, foundations ventilated by outdoor air and parts of buildings where moisture has been built, or leaked, in. Temperature increases lead to more favourable conditions for microbial growth to develop. Furthermore, if the building is cooled in part or throughout, relative humidity will increase in the cold structures, which will also encourage microbial growth. If buildings are to be proofed against humidity and temperature in the future, it is important that the construction sector has climate data for scenarios for which the moisture safety of buildings can be planned. This climate data is not currently available in the simulation software used on the market.
• In the case of measures against driving rain, the industry already displays a need to increase its knowledge of calculations and design in to reduce the risk of water penetration. There is a need for a systematic approach to all parts of a building’s exterior. There is currently room for improvement in this area as there are examples of problems with water penetration in conjunction with torrential rain, and even more so when combined with strong winds. The examples are often due to leaks at connections, joints and penetrations through a building’s exterior.