ᐅ Convert a Terrace into an Extension?

Hello everyone,

We are currently renovating our own home, and the idea of extending the existing terrace into a living area has increasingly come up.

On one hand, the garden is quite large and could be better utilized this way, and on the other hand, it would allow for a much improved living space design. Additionally, the currently installed pergola needs to be removed as some parts are no longer structurally sound.

The single-story new build is planned to be constructed from aerated concrete blocks and feature a wide window front.

Is it possible to raise the existing terrace foundation by about 40 cm (16 inches) using suitable screed concrete?
A joint tape between the screed of the old and new structures is necessary; in that case, will the walls be properly sealed?

This is an initial rough plan to get an idea of the expected costs and effort and to determine whether it might be necessary to hire a construction company for the entire project.

Thanks in advance.

First of all, a building permit / planning permission is required for expanding the living area.
So: the first step is to go to the building authority; if the response is positive, then consult an architect who will submit the building application.
After that, you proceed further.

Good luck with the authorities. Tip: always be polite and friendly, and they will respond kindly as well.

Regards, Yvonne

The step with the building authority has been taken; there is no zoning plan in place, and we still have about 5 meters (16 feet) available in the surrounding area that we are allowed to build on.

The intended or desired measurement is approximately 3.5 meters (11.5 feet).

A standard terrace does not have a foundation but simply a frost-resistant, compacted gravel base.
The extension should be designed by an architect or a master builder; it’s nonsense to just tinker with it on your own.