External walls

The external walls of the 4D building are well-insulated but not necessarily with very thick insulation.

The first part of the insulation thickness has the largest impact. It has only a minor effect on the heat loss to increase the insulation from e.g. 300 to 400 mm.

The focus has been on avoiding thermal bridges - i.e. un-insulated areas in the construction which will increase the heat loss. A construction consisting of insulation + plaster has almost no thermal bridges.

In a wall with a light external cladding, the wooden construction will be a thermal bridge. As a compensation for that, the insulation thickness has to be increased by approx. 25%.

The optimum for the insulation of the 4D-building has not been calculated yet but is supposed to be 250-300 mm for a plastered wall.

The 4D project has three different facade claddings:

• The ground floor requires a robust material, in this case brick has been chosen.
• The offices requires a cladding where hatches for natural ventilation can be integrated. Therefore a panel cladding is chosen for the office facades
• The residence facades have the cladding which has the least thermal bridges, plaster.