Procedure for loans and subsidies in core renovation

Hello everyone,

we are two full-time working people without children. We would like to energetically renovate our house. Key data about the property in BW-southern Black Forest:
Exterior dimensions 10x9 meters fully basement built in 1935 with a double garage built in 1991. The house has two full floors and a converted attic into living space. The last renovation/refurbishment took place in the early 90s: new electrics, floors, installation of oil heating, and windows.

Key data about finances:
6200€ pure monthly net household income without special payments
50,000€ equity,
2000€ repayment rate
6000-8000€ annual special repayment (this is deliberately chosen in case the employment contracts are forcibly reduced from 40h to 35h)
1000€ incidental house costs (insurance, heating, internet, waste, reserves, etc.)

During the joint house inspection, the energy consultant recorded the following points with price estimates:

The total scope without own contribution amounts to approx. 490,000€. I can perform many tasks with friendly craftsmen in self-performance. These include removing screed and windows. I could also do smaller preparations for the electrics. Plastering, painting, and laying floors are also to be done completely by myself. I also trust myself to do the insulation of the cellar ceiling.

I think that the costs can thus be reduced to around 410,000-420,000.

Now my questions:
The total costs seem quite high to me… Are there any experiences on how realistic these really are? We are not planning a high-end golden toilet but overall an upscale standard. Is the estimate of self-performance also realistic?

How would you proceed? A total loan + KFW and work through the individual trades one after the other or with 2-3 loans for 2-3 construction phases and thus get individual BAFA subsidies? Possibly the subsidies would then already be paid out -> smaller loan amount for the next phase..
1st phase roof, insulation, windows, photovoltaic system
2nd phase interior finishing, underfloor heating, electrics, sanitary
3rd phase heating + kitchen

The next steps will be to create a renovation roadmap and for the roof, insulation, and windows offers will be obtained. Depending on the construction design, the funding possibilities will then slowly be explored and applied for.

Is the entire project realistic and feasible? Do you have tips and tricks or further questions to better assess it? I look forward to your feedback!

I can't contribute much, but the photovoltaics seem expensive to me. Earlier this year we bought 12 kWp + storage for around 26k. However, this was before the announcement of the new funding.

Some items are set way too high. How big is the house?

This is a complete renovation. With three floors each having 90 sqm of floor area (+ basement), it amounts to 185 sqm of living space (just roughly estimated). At T€ 490 calculation, you end up with good renovation costs of €2,350/sqm (basement and photovoltaics excluded). This is a completely normal price for what you are planning. Keep in mind that a new build currently costs around €3,500/sqm (plus additional construction costs for basement, photovoltaics, garage, etc.).

Thank you very much for the first feedback! As Karsten correctly estimated, the size of the full floors is around 180 sqm + the developed attic.

What are your experiences with multiple financings of the construction phases? I am still struggling with making one "large" financing right at the beginning, since there will definitely be surprises during the renovation phase... How would the KfW program 261 work in this case? Is my following assumption correct?:

Borrow €120,000 and use it to renew the insulation of the exterior façade, the roof, and the windows. However, only upon reaching an efficiency house level (85-70) would you ultimately receive the repayment subsidy?

How could the amount of €120,000 be increased to €150,000? Currently, we are planning with underfloor heating and the replacement of the oil heating system with a heat pump. Would that then be an Efficiency House 85 Renewable Energy Class?

Kitchen and photovoltaics each -20,000€. Insulation of roof and facade, guest bathroom estimated high but not necessarily too high depending on the region. Windows also estimated very high, but it depends on your standards. 100 for floors, walls, pipes plus 25 for underfloor heating and another 45 for heating also seems very/too high to me. I would, as you say, start with a little over 400 and then deduct something again for the trades where you can contribute your own work.