Within the wooden house sector, a number of different building methods have become established with a variety of load-bearing systems based on joist structures, CLT (Cross-Laminated Timber or Crosslam) or a pillar-beam system. Building techniques can be roughly divided into on-site building and the building of prefabricated elements, flat elements or volume elements. For tall wooden houses a number of ”combination systems” have been tested, i.e. combinations of load-bearing pillar-beam systems and prefabricated volume elements.
There is an increasing demand for wood-based housing, which is considered to be better from an environmental viewpoint, is based on local raw materials and involves components which can easily be transported from factory to site. Developments which have taken place in Sweden have led to two building systems which have been found to be competitive in different market segments: a building system based on CLT which is used for tall buildings with a complicated geometry and open areas, and a system based on volume which is used for more standardised types of buildings and smaller open areas. CLT building and volume modules are both established techniques with a large production capacity, which can in a short time give a large volume capacity for the development of “combination systems”.
The different building methods and load-bearing systems can be divided as follows:
- 1-4 storeys: mainly joist structures in the form of volume and flat elements,
- 4-8 storeys: joist structures and volume elements, or CLT and flat elements, and
- 8-16 storeys: ”combination systems”.
The currently available Swedish wood-based building systems are sufficient for 6-8 storeys, but the ambition and market demand is to be able to build considerably taller buildings, 12-16 storeys in the first stage with a vision of 22 storeys. This development towards increasingly taller wooden buildings raises a number of issues, including the questions of swaying and vibrations in light-weight structures. Innovative solutions and new building systems are required if it is to be possible to build taller and better wooden buildings.
The aim of the project is to develop building components and methods to make possible taller buildings of wood which meet the current norms and requirements, but the goal is to clarify and contribute to the solution of the technical problems involved in wooden buildings of 8-16 storeys.
The project will be divided into two to four sub-projects with the following focus:
- The dynamic properties of tall wooden buildings
- The strength and durability of wooden buildings
- The development of methods of constructing tall wooden buildings with a framework of CLT and/or Glulam in combination with light-weight volume elements.
The project will be a cooperation including Wood Science and Engineering at Luleå University of Technology and SP the built environment in Skellefteå, and it will be carried out as an industrial cooperation between industrial partners in Wood Centre North (TCN).