Floor plan: New construction on existing bungalow basement, 1.5-story

A friend who is a master carpenter had advised us against "upgrading" a bungalow to a 1.5-story house (especially regarding the statics of the ground floor exterior walls and the floor slab). We even had to convince the prefab house provider to preserve the existing cellar. Both parties are certainly biased in their own way. Added to this is the emotional aspect, the desire to build something new and "compromise-free." But we are trying to cautiously take off the blinders regarding building in (instead of just on) existing structures.

Of course, everyone has their interests. But you simply have to be clear that renovating with good building substance is certainly much cheaper and that you also make compromises in new construction. Even if they are only financial in nature. Which brings us to the other topic, because obtaining quotes is all well and good. But it doesn't help much. In retrospect, I would not talk to any prefab house sales representative anymore before I exactly know what I want. Until then, it is a waste of time if everyone tries to convince you of their great system and you end up comparing apples with pears and oranges.

A friend who is a master carpenter advised us against "strengthening" a bungalow into one and a half stories (especially regarding the statics of the ground floor external walls and the floor ceiling). We even had to convince the prefabricated house supplier to keep the existing basement.

I (probably already mentioned that I advise prospective builders) can well imagine a division of labor where the manufacturer of the existing building handles the shell construction of the extension, and a local carpenter / timber construction contractor does the finishing.

The idea was to get a sense of the current price range for our project.

Although this is ultimately a poorly suitable attempt, it is at least an original justification for the comparison of two manufacturers from the luxury and economy market segments.

Someone with the attitude "as long as there are 4 wheels to get me from A to B" will never be willing to pay that much money for a Porsche

My very first Porsche was rented, the one mark per carousel round would also have been a lot of money for me, but my grandpa paid for it :)

and then the children's rooms with 17, 14 and 11.5 m²? Are you trying to provoke a ten-year war over the biggest children's room? Especially since 11.5 m² is really borderline for a children's room.

My brother and I had equally sized children's rooms (totally unfair, since I am the older one), next to each other overlooking the same garden, and yet my brother felt disadvantaged. A school friend of mine even had a smaller room as the older brother (and still got the better A-levels). In a later apartment I then had a bigger room—with a Kim Wilde poster (the keen reader may now guess three times which aspect was more important). Ceterum censeo, whoever thinks the root of world peace lies in equally sized (or even worse: equally big) children's rooms has probably not heard their own screw loose.

I (probably already mentioned that I advise prospective builders,) can well imagine a two-part division, where the manufacturer of the existing building takes care of the shell construction of the extension, and a regional carpenter / timber construction main contractor does the interior finishing.

Although this is ultimately an inadequately suitable attempt, it is at least an original justification for comparing two manufacturers from the market segments luxury and economy.

My very first Porsche was rented, the one mark per carousel round would have actually been a lot of money for me, but my grandfather sponsored it :)

My brother and I had equally sized children's rooms (completely unfair, since I am the older one), located next to each other facing the same garden, and yet my brother felt disadvantaged. A school friend of mine had the older brother even have the smaller room (and still got the better high school diploma). In a later apartment, I then had a bigger room - with a Kim Wilde poster (the kind reader may now guess three times which aspect was more important). Ceterum censeo, whoever believes the root of world peace lies in equally sized (or even worse: equally large) children's rooms has probably not heard their own screw loose.

My brother had the nicer velour carpet and I only had stupid wooden floor with a woven carpet. That was for years the last argument when it came to who was being treated unfairly at the moment. Yes, children are crazy.

The old floor plan already has the potential to move in immediately. You will miss the coziness of the original construction later on.

I can understand your approach, but we would like to build/renovate "properly" to have peace for a few years afterwards. And the existing floor plan would be a downgrade compared to our current living situation. After many years of renting like a nomad, I do not want to put my family through that, and finally want to bring the caravan to the oasis. By coziness, do you specifically mean the living feel of a bungalow, so everything on one level?

Are there already 2-story houses in the neighborhood?

Yes, to the north there is a 2-story house with a flat roof.

Show us some pictures of the house.

We will be on site again over the Christmas weekend; I will take some pictures inside and outside then.

Wow. You are planning a new build, also because of the children, and then the children's rooms are 17, 14, and 11.5 m²?

Good point, honestly I don't know why the rooms turned out to be different sizes. In my opinion, there is nothing against equally (or similarly) sized rooms, and that should be possible here. The bathroom can also be smaller. The bathtub can also be placed lengthwise in the knee wall. We will optimize that in the next floor plan iteration once we have clarified the fundamental questions here.

Looking back, I wouldn’t talk to any prefab house representative again before I know exactly what I want. Until then, it’s a waste of time when everyone tries to convince you of their great system and you compare apples with pears and oranges.

Oh, personally, for me it was quite okay to talk to the prefab house people as a jump start. You can discuss many things and give yourself a small kick-start for the project. The order situation also seems to be declining there so that everyone really took a lot of time for us, including a site visit with an architect. Of course, they want to sell something, and you must not be blinded or have your creativity spoiled.

I (probably already mentioned that I advise prospective builders) could well imagine a split, where the manufacturer of the existing building provides the shell construction for the extension, and a regional carpenter/wood construction general contractor handles the interior finishing.

I wanted to PM you about that too but have probably posted too few posts to be allowed. When will that be enabled? We have two site visits planned now, just before and directly after Christmas, with the local timber builder and a construction technician. The latter was rather skeptical by phone regarding the renovation, especially because of the statics. But we will take a look and also open a wall to check the building substance. I also spoke with a friendly representative of Streif Haus. In the past, renovations/extensions were done in cooperation with Renopan; meanwhile, there is apparently a new (partly in-house) company name that he did not know. Our plans from the 80s are no longer available at Streif Haus, but such inquiries like mine come up often and they are familiar with them. They now have the documents and will get back to us soon. He was basically open to your suggestion of a split (shell construction: Streif Haus, finishing: regional).

I found the conversations with different providers helpful. You just have to remember, the other person wants your money, so they always have the best. You have to filter that out.

Was the house that cheap? It is not a wreck property.

I wanted to PM you about that as well, but I probably haven't made enough posts yet to be allowed to do so. From when will that be enabled?

It should currently be around 150-200