Once again: Renovation vs. New Construction

Hello forum,

I have been quietly reading along for some time and now have a small concern / question myself.

I need an assessment from someone who is familiar with this or perhaps has done something similar before.

I am faced with the decision to renovate an old house or to demolish it and build a new one. It is an older house built in 1936 with solid masonry and about 6cm of air between the inner wall and the outer wall. However, in the case of a renovation, basically everything would have to be renewed (insulation, roof, electrical, pipes, floor, heating, ...) and according to a first rough estimate from an expert, this would cost about 150,000 euros.

The house itself has 160sqm of living space, or even 200sqm with the converted attic. The prerequisite for the project, so that the generational change works, is to add an extension with a granny flat. For this, the existing extension behind the house (built in 1937) would have to be demolished or renovated. However, this extension apparently does not have quite such thick walls and the effort for a renovation would therefore possibly be somewhat higher (internal insulation?). There is no estimate yet for the renovation of the second part.

Now my question, and I know that much has to do with personal taste, but I thought I’d just ask: is the renovation worthwhile in this case? According to the expert, a new build of this quality costs about 1,400 euros per square meter, rather 1,600 euros if you do not want a "catalog" house (so an average of 240,000 euros). Basically, I like the old house (higher ceilings, good layout, solid walls...) but of course I do not want to pay more for a renovation than for a new build. With the renovation, you would also just about reach a KFW100 house, a new build would be more like KFW55 or similar.

So mentally I am comparing the renovation with a new build granny flat to a complete new build. If I leave the granny flat aside, I think I am getting a good price with 150,000 euros for 160sqm of living space, right?

What do you think? Does anyone have experience with this? What would you expect for a complete new build (with granny flat) + demolition?

I apologize for the longer text and hope someone can give a short answer.

Thanks,
Dave

Hello,

of course, I cannot assess the estimated renovation costs of 150,000 euros as such. A cost estimate based on comparable values of m2 living space or similar is not helpful for a renovation. What really helps here is only a cost calculation for each individual component, e.g. replacing x windows of average size in a certain quality, etc. Possibly the mentioned expert also calculated it this way. Otherwise, the 150,000 euros are not a real comparable value to a new build. Because the range can be huge in a renovation; sometimes it is even more expensive than a new build.

The 1,400 - 1,600 euros/m2 for a new build, on the other hand, are realistic, provided the price refers to the living space – of course depending on the desired equipment. However, when considering the energy standard, it should be noted that the kfw-70 standard can generally be achieved with increased wall thickness or insulation (e.g. WDVS - [Wärmedämmverbundsystem]). The kfw-55 standard, however, is only achievable with additional technical components (heat pump, heat recovery, etc.) and significantly increased insulation. Even with a new build, a higher kfw standard is not “automatically” achieved; kfw-55 in particular will have a noticeable impact on the price, especially if you are planning with a basement.

By the way, a granny flat is also a cost factor that must not be underestimated – especially if the apartment is also intended to be rented out to third parties.

If interior insulation is considered for a renovation, I advise caution and the inclusion of a building physicist or a correspondingly experienced professional. There is an increased risk of building damage (mold formation) here.

It is important to consider the total costs for both a renovation and a new build. This also includes incidental construction costs, including planning costs, outdoor facilities, etc. In the case of demolition, do not forget the costs for debris disposal.

Of course, a recommendation for new build or renovation cannot be given to you remotely. To really be able to compare, in my opinion, a reliable cost calculation for a renovation should be prepared. This should be worth it to you – if you are thinking about a renovation. A rough cost estimate does not help here. Because if, as you write, almost everything has to be renewed in a renovation, it may well be that the estimated 150,000 euros are not sufficient.

Hello Dave,

With the renovation, the KFW100 house is just barely reached, a new build would then be more like KFW55 or similar. So mentally, I compare the renovation with a new build of a granny flat to a complete new build. If I leave the granny flat out of the equation, I think that 150,000 euros is a good price for 160 sqm of living space, right?

With a renovation, there usually remains a little "aftertaste" – the basic structure always remains old. I also can’t imagine that the costs estimated by an expert for the main house will match the later reality. It’s not uncommon to start in one place and then only realize later that further renovation is necessary.

Even with a complete new build – and that’s what I would advise you – you can influence the ceiling height; you can even replicate the "old" floor plan 1:1. BUT – everything is then adapted to the applicable energy saving regulations; it doesn’t have to be KFW 55, but KFW 70 is sensible and offers a reasonable price/performance ratio.

I myself live in an old house and unfortunately can’t tear it down; I know very well the differences between valuation reports and reality.

Kind regards

Thank you very much first of all for the quick and friendly responses! Especially because the topic is very individual.

The expert has already recorded the individual measures, such as windows, heating, roof, etc. But of course only roughly estimated, I will request a reliable cost calculation here again, thank you for the hint.

Furthermore, I also do not think that I will manage with the costs. If necessary, I will go through the extension once more with the expert and possibly an architect to see what is feasible. If, even with a buffer and the new construction of the extension, I am still cheaper than with a complete new build, I at least have a rough direction.

Hello again!

In the meantime, the numbers are also available in writing (no offer, an estimate).

Shell construction

[*]Replacement of windows (plastic, triple glazed) 15,000.00 EUR
[*]Core insulation of the exterior masonry 3,000.00 EUR
[*]Renewal of heating, heat distribution, heat transfer 20,000.00 EUR
[*]Support with solar thermal energy 7,000.00 EUR
[*]Attic conversion, insulation, roofing 40,000.00 EUR
[*]Mason (floor plan changes) 10,000.00 EUR
[*]Screed, underfloor heating living room 5,000.00 EUR
[*]Sanitary installation 12,000.00 EUR
[*]Electrical installation 7,000.00 EUR

Interior work

[*]Painting work, interior plaster 9,000.00 EUR
[*]Tiling work 6,000.00 EUR
[*]Floor covering work 8,000.00 EUR

Additional costs

[*]Statics, thermal protection, architect gross 23,000.00 EUR

Total net: 165,000.00 EUR
Total gross: 196,000.00 EUR

Can anyone say something about the numbers? Is this realistic or too expensive? Is something missing? I noticed, for example, that the item "construction management" would at least need to be added, and of course the underfloor heating should not only be installed in the living room.

Furthermore, he estimates that for a new build of the main building with the same external dimensions, costs of approx. total gross: 316,000.00 EUR would arise (including demolition and additional costs). I find that hard to assess.

If someone has done something like this before and knows their own numbers, I would be grateful for any hints (whether this can be accurate).

Best regards from the North,
Dave

Hello Dave,

Total net: 165,000.00 EUR
Total gross: 196,000.00 EUR

if I calculated correctly, it is net EUR 142 thousand and – except for two euros – gross EUR 192 thousand

Can anyone say something about the figures? Is it realistic or too expensive? Is something missing? For example, I noticed that the item "site management" would at least have to be added, and of course the underfloor heating should not only be installed in the living room.

Underfloor heating only in the living room wouldn’t make sense either; involving an external site management is well-invested money.

Whether it fits or not, unfortunately no one here can answer, as we don’t know your building. For example, to me the insulation of the external masonry seems to be set too low. But I could be mistaken …

Furthermore, he estimates that for the new construction of the main building with the same external dimensions, costs of about total gross: 316,000.00 EUR would arise (including demolition and incidental costs). I find this hard to assess.

You wrote 160 sqm/living space in the first post; they should cost around EUR 233 thousand as a KfW 70 efficiency building in the north, plus incidental costs EUR 30 thousand plus demolition costs. If no asbestos was installed in the existing building, the estimate is about right.

So if I roughly calculate now – about EUR 220 thousand (I roughly added costs for the extra underfloor heating and expert fees) for the renovation and EUR 320 thousand for a new building, the figures known so far basically speak for themselves. Personally, I wouldn’t like to spend a lot of money on an “old” box – which will always remain old in its substance – if I had the possibility to build something new in its place. It is – as with everything – a personal decision and there are people who specifically want to preserve these old buildings.

Kind regards