ᐅ Building a Flat Roof Bungalow – Converting an Outbuilding into a Garage Extension

Hello everyone,

I just registered here and would like to ask for your help. I hope you’ll welcome me warmly!

Out of gratitude towards my parents, I would like to move to the countryside where they live soon; more precisely, onto their "plot" – so I can care for them and be there for them in the long term. As is common in rural areas, we have quite a bit of land. Next to the main house, there is an outbuilding estimated to be about 80m2 (860 sq ft) in size, housing the kitchen, garage, etc. We plan to convert this outbuilding into a double garage, with direct access to my future house, which would be located behind it; far from the road and basically hidden.

Now, here’s the point: I would like to build a flat-roof bungalow of about 100m2 (1,080 sq ft) behind this outbuilding. It should look modern and stylish from the outside, but I believe that with a good sense of design, this can be achieved without expensive luxury materials – please correct me if I’m wrong. I would like the bungalow to have a white plaster finish, a few copper elements in the walls here and there, and floor-to-ceiling windows throughout. Inside, I want parquet flooring in the living room, hallway, and study, and large dark tiles in the rest of the house – preferably with underfloor heating everywhere; that might be costly – and ideally a fireplace as well.

I don’t need a basement, and one bathroom will be sufficient.

I’m interested to know roughly what costs I can expect – as mentioned, the land is already owned. If you have any questions that can help to give a more accurate price estimate, please ask! I’m young and haven’t been dealing with this topic for long.

Also, a question about the flat roof: how is drainage managed? Since the roof doesn’t have a slope, the rainwater isn’t really directed into gutters in the usual way. I hope this question makes sense (and isn’t too silly).

Thanks so much to anyone who read this and may be able to help!

Get a copy of the zoning plan (Bebauungsplan) or check it online to find out if and what you are allowed to build. It is possible that building on the remaining part of the plot is prohibited, or that the floor area ratio restricts you. In that case, a bungalow might not be permitted. White exterior plaster is also not allowed everywhere.

I don’t think you have given this much thought.

Best regards, Yvonne

ypg schrieb:
Get a copy of the development plan (building plan) or check it online to find out if and what you are allowed to build. It might be that you are not allowed to build on the remaining part of the property or that the floor area ratio restricts you. In that case, a bungalow might not be permitted. White exterior render is also not allowed everywhere.

I don’t think you have really considered this before

Best regards, Yvonne

Hello Yvonne,

Thank you very much for your willingness to help. To my and my mother’s knowledge (she is the owner of the property), none of the issues you mentioned apply here. Otherwise, I can build on one of the other plots, so there should be a solution if needed.

I am not looking for an exact price; it would be enough for me to know whether I am roughly in the range of 100-150 thousand euros, 150-200 thousand euros, or higher. I would really appreciate any kind of estimate.

Thanks again to you and everyone who is considering my situation.

A 100 m² (1,076 sq ft) bungalow is available starting at 120,000 in the special offer. With some extras (some of which are really essential), the price goes up to around 140,000. Then you have to add another 30,000 to 40,000 for additional costs, bringing the total to approximately 180,000 without the land.

Before you dive deeper into this, you should really make sure whether you are even allowed to build there. My father owns over 20 hectares (200,000 m² / 2,153,000 sq ft) of land, but I am not allowed to build a house anywhere on it...

White render is often poorly applied and can easily turn rusty red, moss green, or moldy black. Keep this in mind, and if that’s the case, make sure you don’t mount a rusty lantern, plant a fir tree next to the house, or run the kitchen exhaust duct directly along the wall.

I would estimate the cost from moe to be around 1400–1500 € per square meter (about 130–140 USD per square foot), depending on the region; it might be somewhat cheaper if you know local tradespeople.

Flat roofs are not completely flat—they still have a slope to allow water to drain properly.