Does this conversion count as new construction?

Hello everyone

I am currently considering converting a vehicle storage hall into a residential building. The old roof structure is to be removed and a timber frame extension is to be built on top. A company that does this kind of work has already been involved.

The technician said that the project is classified as new construction. This surprises me a bit since the original walls of the storage hall will remain and it will also partly be used as living space in the future.

Now I am wondering from when a conversion legally counts as new construction?
What advantages and disadvantages can I expect depending on whether it is classified as a conversion or new construction? I assume that the legal requirements are considerably stricter for new construction. How do the KfW subsidies compare between old buildings and renovations?

What must be fulfilled for the project to be considered a conversion?

THANK YOU FOR YOUR HELP.

Well, you are already building a new story on top (Aufstockung). You will definitely need a building permit for that! Furthermore, you are also changing the use of the building, is there a permit for that? Architect and structural engineer available to plan? Sure, people often say that you are "remodeling" - but it won't work without a permit.

If you move a wall inside the building or change the floor plan, then you have a renovation.

Hello nordanney

I am aware that a building permit is required. I am also fully aware that the type of use must be approved. I assumed that a permit is also needed for a conversion.

You are creating a residential building where there was none before.
Means: You must build according to the [Energieeinsparverordnung].

What advantages and disadvantages can I expect depending on whether it is a renovation or a new build? .

The Energy Saving Ordinance must always be observed. Whether § 9 para. 1 or § 9 para. 4 or § 9 para. 5 or § 3 of the Energy Saving Ordinance applies to you cannot always be answered so easily and generally for existing renovations. It depends and your planner must know.

What you intend is a change of use, which is per se subject to a building permit. Then, the currently applicable building and planning laws as well as other legal requirements, such as the Energy Saving Ordinance, must be applied. Conversions are only not subject to a building permit if they involve minor interventions in the existing structure, e.g., breaking door and window openings that can be covered with commercially available lintels. Depending on the existing situation, however, a window or door opening wider than 1 meter is a matter for the structural engineer (lintel design/load transfer, etc.).

In your case, I strongly recommend working with an architect from the outset who first clarifies and assesses the building and planning law situation and realistically shows you what options you really have in your situation. If the carriage house, for example, is on the boundary, setback areas to the neighbor may be triggered and special fire protection issues related to the so-called "building separating wall" may arise.

Presumably, the architect will also first have to submit a preliminary building inquiry to clarify the fundamental feasibility of the construction project.