Turnkey Energy Retrofit Assessment

Good evening everyone,
I am currently planning a complete renovation to an energy-efficient house. For this, I have obtained quotes and, after an initial inspection and discussions, received a complete offer (turnkey) at a fixed price.
This amounts to €450,000 plus an additional €18,500 for a photovoltaic system. According to current calculations, this will achieve the Effizienzhaus 55EE – possibly even 40EE; whether the additional costs are worthwhile is currently being calculated. So far, we are looking at a subsidy of about €135,000.
Here are a few key points of the turnkey renovation:

[*]Construction site setup (toilet, construction power distributor, scaffolding, crane)
[*]Adjustments to masonry for new windows, doors, and partition walls
[*]New screed on ground and upper floors
[*]Delivery and installation of approx. 10 windows as well as front door/side door (Veka V 82 MD, thermal insulation glass)
[*]Spray foam insulation of basement ceiling
[*]Renewal of complete electrical system, preparation for wallbox
[*]Renewal of all supply and drainage pipes
[*]Installation of underfloor heating on ground and upper floors
[*]Installation of air/water split heat pump
[*]Installation of ~ 9 kWp photovoltaic system as well as 10 kWh storage
[*]Decentralized ventilation system with heat recovery
[*]Renewal of staircase (steps/railings)
[*]New sanitary facilities for 2 bathrooms and 1 toilet – all tiled
[*]All walls and ceilings plastered with Q4 finish and wallpapered with smooth fleece
[*]Facade plaster and paint
[*]Vinyl flooring in living areas
[*]New exterior walls in timber frame construction with cellulose insulation
[*]Roof renovation: new rafters, insulation (24 cm cellulose), new clay tiles
[*]New dormer with natural slate cladding

However, we will take care of the demolition of the old exterior walls, windows, and doors as well as their disposal ourselves.
The building has a living area of 126 m² and a basement area of 17 m². Built in 1969 – there was a small extension in 1999, but the house has never undergone a significant renovation.
Since this is quite a lot of money and I have not had much contact with the topic of (energetic) renovation before, I would like to get a first assessment or orientation. Thank you in advance, and I hope for good advice and/or suggestions for improvement!
Many thanks and best regards
Jan

Good tip: Tear the house down completely and build a new one there, it won't be more expensive...

If you still want to "renovate": Why one would integrate a decentralized ventilation system in such a renovation is surprising. You're doing everything new anyway, so just install a central one.
Who is planning all this? Or did you go to a construction company and ask "How much does 10 kilograms of complete renovation cost"?

I want to get such a first assessment or orientation.

You can get that.

==> tear the house down and rebuild

New exterior walls in timber frame construction with cellulose insulation

Demolition of the old exterior walls

What nonsense.

New construction will probably (almost certainly) be cheaper and then it is also a new building.


P.S. Two bathrooms and one toilet on 126 sqm of living space. May I ask if you still have living space for the people who can use all the sanitary facilities?

You can get it.

==> tear the house down and rebuild



What nonsense.

A new build will probably (almost certainly) be cheaper and is then also a new build.


P.S. On 126sqm living space two bathrooms and a WC. May I ask if you still have living space for the people who can use all the sanitary facilities?

So far, I have received feedback that a demolition + new build in this area is actually quite a bit more expensive. Especially because of the subsidy..
Since I like the floor plan 95% and afterwards you basically have "the whole house" regarding the expansion of heating/electrics, etc., I currently see the advantage of renovation. But thanks anyway for your assessment - as I said, I'm pretty new to this topic^^

Due to the timber frame construction including insulation, the subsidy for serial renovation can be used. That promises further advantages in funding compared to the "classic insulation".

Yes, the planning of the bathrooms is not final yet, I tend more to one bathroom + WC - but we'll see..

Good tip: Tear down the whole place and build a new house there, it won’t be more expensive...

If you still want to "renovate": It’s surprising why you would integrate a decentralized ventilation system in such a renovation. You’re redoing everything anyway, so just install a central one.
Who is planning all this? Or did you go to a construction company and ask, "How much does 10 kilograms of complete renovation cost?"

So far, I have received feedback that demolition + new construction in this area is actually quite a bit more expensive. Especially due to the subsidies...
Since the floor plan pleases me 95% and afterwards you basically have the "whole place" in terms of the expansion of heating/electricity etc., I currently still see the advantage of renovation here. But thanks anyway for your assessment – as I said, I’m pretty new to the subject^^

I am currently living with a decentralized ventilation system and can’t detect anything negative about it so far?

Basically: The planning/calculations are done by a construction company with an energy consultant.

Due to the timber frame construction including insulation, the funding for serial renovation can be used. This promises additional advantages in funding compared to the "classic insulation".

Don’t do a renovation just for the sake of funding. If there are other options, please check those as well.

I am currently living with a decentralized ventilation system and can’t notice anything negative so far?

No, that is also good for renovation. But a central system is even better. However, that requires ventilation ducts. If you can somehow hide those, without, for example, necessarily suspending the ceiling and thus losing height, then switch to central.

So currently we come to a funding amount of about €135,000.

Just a quick question, how do you come to that? Maybe it’s already too late, but if you are aiming for 55E + serial renovation, KfW "only" gives 20% + 15% as a repayment bonus on a maximum loan of €150k. That is over €80k less funding than you write. Or are you including other subsidies?