Demolition or renovation? Looking for tips for basements from the 1970s!

Hello everyone,

we are in the process of purchasing a house from 1973 and are now faced with the question of how to deal with the basement. The house itself is not worth preserving. We are wondering whether to rebuild or if it makes more sense to keep the basement and build on top of it. We hope that renovating will be cheaper and create more living space.

Since we are not experts, we wanted to ask here in the forum for experiences and tips:

[*]Check the condition of the basement:
The basement looks solid at first glance, but of course this is just a layman's assessment. From your point of view, what are the most important steps to have the condition of the basement professionally evaluated? Should one directly hire an appraiser or structural engineer here?


[*]Renovation or demolition:
Does anyone have experience with whether it is more economical in such a case to renovate the basement or demolish it completely? Are there typical problems with basements from the 1970s that one should consider (e.g. structural stability)?



[*]Experiences with similar projects:
Who among you has faced a similar decision before? What was decisive for your choice – and would you make the same decision again in hindsight?

I look forward to your experience reports, advice or also hints on what else we should pay attention to. Every idea helps us to make the right decision for our project!

Thank you in advance and best regards

we are in the process of acquiring a house from 1973 and are now faced with the question of how to deal with the basement. The house itself is not worth preserving. We are wondering whether to build new or if it makes more sense to keep the basement and build on top of it. We hope to be cheaper with a renovation and to gain more living space.

I am happy to respond to your three questions – best after you have shown the existing basement from the building file (and regardless of not wanting to use it) as well as the house standing on it.

To save you the search through my numerous posts on the keyword existing basement, I have put together a library for you here – partly ordered by relevance, partly containing links to several other relevant posts or threads:

In most basements, there is unlikely to be a structural problem. There are 2 problem areas. * Moisture due to missing or damaged sealing/drainage ==> can be fixed by excavation * Missing insulation ==> can be fixed on the exterior walls by excavation, but not under the floor slab. The question is whether the floor plan/room height fits and what you want to do with the basement. Demolition will probably be more expensive than a new build on a greenfield site.

In very few basements is there likely to be a structural problem. There are 2 problem areas. * Moisture due to missing or defective sealing/drainage ==> can be fixed by excavation * missing insulation ==> can be fixed on the exterior walls by excavation, but not under the floor slab. The question is whether the floor plan / room height fits and what you want to do with the basement. Demolition will probably be more expensive than a new build on a greenfield site

A structural engineer is still necessary, I assume? What costs should I budget for (I came across about €5,000 for structural engineering in the forum)?

I am not aware of any damp spots. The basement is not insulated, corresponding to the year it was built.

[*]The exterior wall is 30cm thick
[*]It stands on 40cm strip foundations
[*]The shell height should be 2.50m, rooms about 2.40m – I would make it higher for a new build, but I find it acceptable.

I now believe a demolition and new build will be significantly more expensive.

[*]Demolition costs at least €20,000
[*]Only makes sense if it’s a residential basement, including finishing ~ €2,000 / sqm
[*]New connection costs and possibly surprises, higher incidental building costs, and the plot/garden will be affected...
[*]For 140 sqm x 2,000 = 280 + 20 demolition + X = 300,000€ + X
[*]Added value: Higher rooms, everything from one source, lower heating costs, current standard.
[*]300,000€ vs. preservation, possibly facade insulation and new windows – I claim I’m significantly cheaper that way
[*]€100,000 saved corresponds to about €400 monthly burden on the loan instalment; one would never spend that much just on heating costs.

Thinking error?

A crucial point: What has to be done with the basement ceiling before something new can be installed on top? Insulation – anything else? Costs?

Is it possible and allowed to continue using the "old" oil heating in the basement while building upstairs with a heat pump?

I am happy to respond to your three questions – best after you have shown the existing basement from the building file (and regardless of not wanting to use it) as well as the house standing on it.

To save you the search through my numerous posts on the keyword existing basement, I have compiled a library for you here – partly sorted by relevance, partly containing links to several other relevant posts or threads:

Attached are the house, basement, and foundation. I still have to review the building file.

Thank you very much for the compilation, I will work my way through it. It would be interesting to learn how the implementation went.

The house itself is not worth preserving.

Isn’t it an AB Elementhus, for which there is finally a thread here with good exchange between the renovating buyers of similar models? – what is the decisive factor in your case to avoid this path?

Attached house, cellar and foundation. I still have to review the building files.

Picture 2 of the cellar and the section would be good again with the upper dimension line and generally more contrast on the dimension lines.

It would be interesting to learn how the implementation went.

finished a house, but the case was different in that the cellar was not attached to a house; bought a plot with a cellar and a cleared burnt wooden house; and had a basically good used house, but its extension was not economically attractive due to structural weakness (of the house, not the cellar), and as far as I know, he is not yet finished but has decided what he now wants to build on it. So one case (33055) finished, one case (35388) I do not know how far, and one case (44686) possibly already well advanced but not yet fully documented here.