Small house in existing stock - how to enlarge?

Hello dear forum members,

I would be very grateful for your collective knowledge! Specifically, how can we best enlarge our living space?
We (35, 34, 0 years) live in a 49m² house (built in 1996) on a nearly 900m² plot west of Berlin. We are considering enlarging, and I see the following options:
- extend,
- demolish and rebuild,
- first build a terrace/winter garden + garden shed at the very back and keep saving for the house construction,
- do nothing, keep saving.
We have owned the house for a few years, €310k is still to be paid off, so we would need a second mortgage for the construction. Here are some details about the property: exterior walls are made of 30cm hollow block, the attic is not really expandable as it is, we replaced the gas boiler two years ago and the new one is oversized. Two houses on one plot are not permitted, so a new building in the back, for example without demolition, will not be approved. There is no development plan, but §34 applies.
Attached is a north-oriented picture of the parcel; the garage at the front has already been demolished, and the green figure is meant to represent a protected tree.
What would your line of thinking be, how should we approach this or what information would you need?
Thank you very much for any suggestions!

I would:

[*]look for old building plans and immediately copy and scan them,
[*]gather property documents and also copy + scan them
[*]investigate the building materials of the hut
[*]mark all incoming utilities on the plans
[*]assess (have assessed) the condition (each trade) regarding energy values, statics, future viability, current condition, etc.
[*]write down the new overall requirements
[*]take everything and go to the architect of your choice

We can also take a look and give a first assessment. However, the evaluation of the condition can probably only be done by a specialist on site.

Maybe you could post a picture to clarify here whether it is a house or a hut. After the 34er, you could build even bigger. A house from 1996 is not just torn down like that. Ultimately, without an architect who can build a house onto/around a hut, at least from a planning perspective, it will not be feasible.

Extending is definitely the best solution.

I would:

[*]Have the substance (each trade) assessed regarding energy values, statics, future viability, current condition, etc.

Hello Katja, thank you very much for the valuable tips! Regarding connections, we have already found that the markings in the documents from the house construction period, those from the supplier, and where the cables actually lie – all three are completely different things. I would like to follow the advice to have the house examined. Should individual appointments be made for each trade, or could some expert cover them all? Hello ypg, the sun is currently unfavorable, so only part of the exterior wall is visible in the picture, but it is about a house. It was built back then for a single person; that’s why it is so small.

We had hired a civil engineer at the time, who was also a construction manager and general contractor, for an assessment. He went through the house and was able to evaluate almost everything and said what needed to be done. When it comes to exact figures, the respective specialist has to assess the situation anyway.