Variation when you need to tear down a wall or install a new window – Here's how to do it right from the start

Demolishing a load-bearing wall or creating a new opening for a window requires careful planning and the right technical solutions. One of the most important parts of the process is bracing , which ensures that the building structure remains stable and safe. Here we review what variation means, when it is necessary, and how to do it correctly.

What is variation and why is it important?

Partitioning means strengthening the structure of a building when a load-bearing part is removed, for example by demolishing a wall or installing a window or door. This is done by installing a beam (often made of steel or glulam) that takes the loads from the building parts above and distributes them to the sides of the opening.

If the displacement is not carried out correctly, it can lead to cracks in the walls, subsidence in the house or, in the worst case, the risk of collapse .

When is a change necessary?

Variation is required when:

✅ A load-bearing wall must be demolished – If the wall supports joists or ceilings, a beam must be installed to replace the load-bearing function.

✅ A window or doorway should be made larger – If you want to expand an existing opening, the load above it must be handled correctly.

✅ A new window must be installed in a load-bearing wall – Opening an opening requires adjusting the load distribution.

Building notification and requirements from the municipality

When you submit a building application for a change of use, the municipality usually requires the following:

📌 Construction drawing – A detailed drawing showing how the conversion will be carried out.

📌 Construction documentation – A technical description of the supporting elements, including material selection and methods.

📌 Dimensioning check – Calculations that show that the exchange beam is strong enough to carry the load.

These documents must be prepared by a civil engineer or designer and attached to the building application in order for the municipality to approve the measure.

How to make a correct change

1. Check the load-bearing capacity of the wall

   – Check the building's drawings or contact a structural engineer to determine if the wall is load-bearing.

2. Choose the right replacement bar

   – The beam is dimensioned according to the load. Common materials are glulam, steel or LVL beams .

3. Support the structure before demolition

   – Before removing the wall, temporary supports (e.g. jacks or posts) must be installed to hold up the roof and rafters.

4. Install the diverter bar

   – The beam is placed in a joist or on columns that carry the load down to the foundation.

5. Final inspection and follow-up work

   – Make sure that the transition is carried out correctly and finish with filling, painting or installing moldings if necessary.

   
   

Important things to consider when switching

🔹 Building application and municipal requirements – Make sure you have the correct documentation ready before starting the project.

🔹 Hire a professional – Improper replacement can lead to major damage. Seek help from a structural engineer if you are unsure.

🔹 Material selection and sizing – A beam that is too small can cause subsidence, while an oversized beam takes up unnecessary space.

How much does a change cost?

• How much it costs to produce the correct documents for a change of address for the municipality and the construction company depends on several factors.

  • How many variations should be made?

  • Whether it is a new or old house affects the ability to know what the existing frame and wall are like, which requires more investigation or not.

  • Does your municipality want to have dimensioning control and construction documentation or not?