Complete renovation of a 150 sqm semi-detached house built in 1925

We are renovating an approx. 160 sqm house COMPLETELY to monument standards. Including new roof truss, insulation, new intermediate ceilings, windows, heating, floors, plumbing, facade ... and will end up at about 250,000.

Including incidental costs and architect?

For the same measures as Myrna_Loy, I also spent around €250,000. Also everything new including new dormers, facade insulation, completely new interior plaster, breakthroughs, etc. However, I did not have a monument and the intermediate ceilings remained in my case.

I imposed the monument preservation standard on myself because I find nothing more dreadful than old building renovations where someone tried to turn a cow into a racehorse using a saddle and paint. My environmental contribution is not triple-glazed KfW with all the bells and whistles, but a building that was simply constructed in a very resource-saving way and in which all materials - except for the sewage/electrical systems or window seals - are free of plastics. In terms of ecological balance, despite only double-glazed wooden windows and a 200-year-old front door, I have no qualms. Of course, you can also spend > 3000 €/sqm on a renovation - but it is not a natural law that a renovation costs as much as a new build.

First of all, thank you very much for the feedback.

I have attached a few pictures. The problem is that the floor plan is definitely not correct as it is shown in the pictures. For example, the passageway from picture 3 cannot be found anywhere else, and there is a shower in the bathroom on the ground floor. We will have to ask about that tomorrow.

Regarding the costs again. Our architect gave us a sample invoice for a new build from 2019 last year (we sat down with her for about 3 hours and expressed our wishes). I simply added 10% to that and rounded up again; everything marked with an asterisk comes from that sample. The invoice for the sample house was 160 sqm and detached – so I think this should be rather conservative for a 150 sqm semi-detached house. That results in this estimate here – is this unrealistically expensive? When I consult Dr. Google, for example regarding heating, I come to about €20K for a wood pellet system plus costs for underfloor heating, if possible (~€15K), so quite close to this. I have no idea about gutting and floor plan work, I just saw €87/sqm for gutting and €1000/sqm wall area for openings with steel beams on Google and calculated a bit more generously. We can definitely save on windows, as she specified colored ones on both sides, which we don't need. Stairs are another example, there are simply many: front door, then basement-ground floor-first floor-attic and house/terrace->garden. Please feel free to share your opinion: Which items are set significantly too high, which are missing (except for painting and outdoor facilities – the latter not required, the former we will probably do ourselves with small children rather than ruining the expensively paid paint job on day 1 :)).

Cost item	Cost (€)
Gutting (100€/sqm, incl. disposal)	15000
Floor plan work (ground floor – unclear how much is needed -> floor plan not exact)	25000
Bathrooms (2 bathrooms (ground floor, 1st floor) – attic repurposing – both bathrooms have a shower or shower + bathtub)	30000
Flooring (80€/sqm finished laid)*	12000
Plaster (inside)*	10000
Electrical*	15000
Windows (large sliding door ground floor + partly floor-to-ceiling windows elsewhere)*	35000
Heating (if with underfloor heating, ceiling height? -> otherwise cheaper?)*	40000
Screed*	10000
Kitchen*	14000
Electric sun protection* (nice to have, electric version candidate for removal)	11000
Terrace(s) (larger terrace on raised ground floor at the rear, small terrace in front?)	15000
Facade (ETICS)*	35000
Insulation (inside, e.g. basement ceiling or attic ceiling if necessary)	7000
Stairs (ground floor -> 1st floor, 1st floor -> attic), basement stairs? external stairs?	15000
Front door*	3500
Interior doors*	4000
Window sills inside*	1000
Scaffold for plaster work*	5500
Total	297500

Charming house! but the offer is a case of cow to racehorse when floor-to-ceiling windows with sliding doors and 11,000 euros for sun protection are factored in. :D I am also old-fashioned, I think you shouldn't renovate a semi-detached house too differently in terms of window formats. After that, the whole building looks shabby. If you try to completely turn an old building into a new one, then it just gets expensive. And often not beautiful.

Then I come to this calculation here - is it unrealistically expensive?

ROFL - yes, it is unrealistically expensive. Example screed: you can estimate the sqm at €20 (very roughly, depending on type and thickness) - not three times that. Example windows: way too expensive, unless you change all kinds of windows in size and choose the most expensive wood/aluminum version in the special paint finish Sonnengoldmetallic. ==> 24 windows including aluminum front door and HSK terrace door approx. €25k (49 sqm including electric shutters, WK2 fittings and RAL installation, KFW 55 compliant, special color outside) - currently being installed by a German company - so no Polish crew (although I really appreciate the Poles in this area!) Example stairs: What does stairs mean? New stairs or just new coverings? Example heating: Could fit, if with controlled residential ventilation and geothermal energy and other gimmicks. Otherwise way too expensive - even with underfloor heating. Example gutting/floor plan: Gutting 120 sqm (clean separation of construction waste, parquet strips + screed disposal) was about €4k for me a few months ago. Including gutting bathrooms and small floor plan change (removing kitchen wall). With €15k you can gut AND adjust the floor plan. Etc. Electric sun protection: Already included in the too expensive windows and means electric shutters - so delete this item. These are absolute luxury prices. Maybe the architect has the right craftsmen for the trades who allow themselves to charge these prices.

It depends on what you want. If you dream of the so currently trendy 08/15 minimalist open space in oak and concrete with floor-to-ceiling glass in all rooms, like in new builds, it will get expensive. For example, I would try to save the floorboards and preserve the actually nice floor plan. More tango than wrestling when dealing with the substance. Maybe look for architects specializing in building preservation again. And perhaps consider whether the money saved by a stripped-down, house-appropriate renovation should be kept in reserve in case a bidding war occurs.