Check cost estimate from preliminary draft

Hello everyone,

We want to fundamentally renovate our house from 1930 in ZIP code 38xxx, insulate it, and expand the attic for additional living space. In this process, we will also renew the guest WC and divide some rooms...

Now we have finally received the preliminary draft from our architect for our house. I’ll spare you the proposed floor plans for now, as in my opinion, they are very much in need of improvement.

For understanding the cost estimate, it should be said that our architect wants to close the access to our basement from the inside for thermal protection reasons and create a separate external access.

In the past, our architect forgot to include the tiles and the laying in the cost estimate, I had to point out errors in the KfW subsidy calculation, and he wanted to create a ventilation concept after renovation based solely on window casement vents, even though I clearly stated from the beginning that I want a residential ventilation system.
Strangely, according to the cost estimate, we exactly meet our maximum budget...

My trust in the estimate is therefore not very high.
What I would be interested in is whether you consider the unit prices in the cost estimate to be realistic or not, and which work might be completely missing.

I am missing:
- Painting / filling work
- Laying / piping work for controlled residential ventilation
- Electrical work (possibly included as a lump sum in the socket price?)
...

The prices seem low to me among others in:
- Windows
- Doors
...

Just to clarify: For me, a "Budget is not sufficient" result from the preliminary draft is more valuable than a preliminary draft that looks nice at first but where the costs later explode.

Many thanks in advance
SoL

Good morning,

What about the heating/water pipes? Aren't they supposed to be replaced? In the calculation, I see the renewal of 3 bathrooms (3 WCs), but you mention a guest WC above? For three bathrooms, I find it too low.

I only checked with my phone and may have overlooked something. But I can say that electrical and sanitary installations, heating are not exactly cheap :( That seems too inexpensive to me. But maybe I missed something.

Besides heating/water (as has already written), I also have questions about the electrical work and painting. Especially if it gets that expensive.

The windows with two sashes and [Wiener Sprosse] seem to me to be underestimated in height. German, Danish, or Polish manufacturer? Plastic or wood?

Another question: Does your energy consultant say that the basement access inside must be completely sealed? Isn't an interior door sufficient for KfW 70? I would only use an external access as the sole entry option if I really have to.

Hello everyone,

Thanks already for the previous answers.
Regarding the follow-up questions:
- In general: We have only completed the preliminary draft, now the question is whether we continue and if so, whether with this architect
- Windows made of plastic, manufacturer unspecified
- Heating (gas condensing) remains, piping remains in most parts of the house, only the attic gets new heating pipes due to the conversion. There, underfloor heating; rest of the house normal radiators
- Electricity also remains mostly, fuse box will be new and in the attic due to the conversion
- Basement stairs: Our architect wanted to go for KFW55, now had to revert to KFW70 because according to his calculations it is not sufficient for KFW55. Basement stairs outside are also not my favorite, especially since there is actually no space for the stairs anywhere...
- About the bathrooms: Architect plans with 3 bathrooms (at very low costs from our point of view), we would like to keep the main bathroom, we only renovated it 8 years ago and still like it very much. Thus, we would have the tiling and sanitary budget available for the renovation of the shower bathroom on the ground floor and the shower bathroom in the attic

Hope the information helps somewhat, otherwise just let me know...

Best regards
SoL