The foundation insulation

Energy is expensive and environmental awareness has also increased. Therefore, the efficient thermal insulation of houses has long been part of the technical construction standard. Also the foundation or / and the bottom plate are insulated accordingly. How the foundation insulation is structured, we have summarized below for you.

The modern energy-efficient house

Modern houses have long been built so that no more heat escapes. Energy-efficient homes are particularly efficient here. In contrast to conventionally built houses, they have an airtight building envelope. Depending on the requirements, this consists of:

  • warm roof
  • airtight and insulated facade
  • white basement sink

Foundation insulation or insulation of the floor slab

The possibilities for saving energy now go so far as to insulate hitherto largely uninsulated areas. The foundation or the floor plate is one of them. So good insulation of the foundation can save up to 10 percent of energy.

Construction of the insulated foundation

The structure of the foundation does not differ significantly from a frost-resistant foundation. First, the pit is dug and the sole compacted. Then fill with gravel or gravel (conventional in the grain size 16/32 mm). This gravel layer is also compressed again.

The insulating material for the foundation insulation

Now the further structure can differ in the following order. This is followed by a film or bituminous membrane seal, then a slurry layer of lean concrete. On or before that are foam boards (XPS EPS) and take over the thermal insulation. Now the actual foundation with a reinforcement is executed.

Foundation insulation rather with base plate without basement

However, the foundation isolation in a basement house is rather the exception. It is much more likely to be performed on a base plate without a foundation. Even then it can be a strip foundation or a foundation plate. In addition, during construction without a basement, the production of a frost protection apron made of concrete around the actual foundation or the floor slab takes place.

The implementation of the foundation insulation

The various dimensions, such as the thicknesses of the various foundation layers, as well as the insulation material, are carried out by executing architects or structural engineers. After all, you need a building permit for the foundation as well as for the house, and only the building plans prepared by the architect or structural engineer can be approved.

Tips & Tricks

Even if a foundation insulation according to the Energy Saving Ordinance EnEV is not yet a duty today, you will equip your new building optimally for the future. After all, you can no longer insulate the foundation or the floor slab from outside or below.

Artikelbild: serato / Shutterstock

Video Board: Foundation Insulation Effectiveness: Basement building science