Financing volume 410k € Feasibility assessment

Hey folks, I have no idea why I was linked here in another thread and unfortunately don’t have time to read through the 45 pages there. Maybe there are some parallels, but be that as it may. Let’s keep it factual here :)
So, I received a current daily calculation yesterday (according to his latest tenders, including the neighboring house he planned and is currently overseeing) from my architect. To recap the rough key data: 145 sqm living space, 200 sqm with usable area, basement due to hillside location, garage in the basement. 675 sqm plot (land value 85 € / sqm) is paid for.
Basement is brick-built, no waterproof concrete (no “white tub”). House without frills, gable roof without dormers, etc.
High-end standard fittings (here I see, depending on price development, some potential to reduce certain items a bit)

Architect’s assessment of the material situation: wood tends to get more expensive again, construction steel cheaper, on average everything is expected to stabilize at current prices, they won’t fall again. Availability is okay again now. Of course no guarantee, but a crazy year like last one seems rather unlikely.

Earthworks: €10,250
Shell construction works: €142,000
Sealing works: €8,300
Sewer works: €3,570
Carpentry works: €12,500
Roofers and plumbers: €17,850
Scaffolding: €3,000
Windows, front door, garage door: €27,300
Electric: €17,850
Heating / sanitary: €46,500
Interior plaster: €20,250
Interior finishing / insulation: €23,800
Screed: €6,000
Tiling works: €9,520
Joinery works: €9,520
Railings: €3,000
Floor covering works: €19,040
Painting works: €15,500
Exterior plaster: €19,000
Terrace sealing and covering (loggia on garage): €3,500
House connections: €4,200

Additional costs:

Architecture, statics and construction supervision: €28,850
Surveying: €3,250
Building permit: €900

That makes a total of €455,000.

Now I noticed that quite some additional costs are still missing, and I tried to inform myself as comprehensively as possible and would like to ask you to check for completeness if you want:

Insurances: €1,500
Construction power / construction water: €3,500
Porta potty: €250 borrowed from a buddy
Construction fence: €250 borrowed from a buddy
Registration of mortgage: €2,000
Test engineer?! According to my research in NRW not required for building class 1-2
Possibly removal and landfill?! Architect says he gladly takes the remaining soil that is not needed for other construction projects, he constantly has demand, but would probably still want to budget something

Outdoor facilities: €20,000 (to be done step by step, materials only, rest DIY – still want to include material costs in financing)
Kitchen: €15,000
Furniture etc.: €7,500

When I add up the amounts, deduct our equity and own work (which are still calculated rather conservatively), I come to a financing amount of €405k.

About our own work: shell construction by a bricklayer crew with 3 people + building materials directly by the client and client’s help. Joinery by father-in-law (joiner), earthworks by buddy (I rent the excavator directly, he carries out the work), electric by brother-in-law (master craftsman), floors, painting, interior insulation and drywall myself. For quite a few trades I know people (as it is in the countryside...), but that would then flow in rather spontaneously and is initially not included.

All amounts are gross values. Do you find this plausible, or what do you notice / what is missing?

Best regards

Man if you do so much yourself, I would award the other trades myself and only buy expert help as soon as needed. The money saved you should rather invest in high-quality building materials. [innenputz 20k] is really a lot, [q2 gips putz] should be around €9.50/m2 net, for example. Otherwise, the prices seem realistic to me.

Man if you do so much yourself, I would award the other trades myself and only buy in expert help as soon as needed.
You should rather invest the saved money in high-quality building materials.
Interior plaster 20k is way too much, Q2 gypsum plaster should be around 9.50€/m2 net, for example.
Otherwise, the prices seem realistic to me

Thanks for your feedback. Yes, we do a lot ourselves and the plan was at first also not to have the architect handle the tender and construction supervision, but I feel somehow safer now, as of now and also after yesterday’s appointment. There is still uncertainty that something might go completely wrong and then you stand there completely alone and lost. Many have already told me, save those 10,000 €, in the end you have to take care of every little thing yourself with the architect anyway ... but I don’t know ... I think you should rather do that if you have experience with construction projects ...

What exactly do you mean by expert help, if needed?

Thanks for your feedback. Yes, we are already doing a lot ourselves and initially it was also planned not to have the architect handle the tendering and construction supervision, but with the current status and also after yesterday’s appointment, I somehow feel more secure. There is still uncertainty that something might go completely wrong and then you end up completely alone and lost. Many have already told me, save the 10,000 €, in the end you have to deal with every little thing yourself even with an architect ... but I don’t know ... I think you should rather do that if you have experience with construction projects ...

What exactly do you mean by expert help, if needed?

You grow into a house building project by yourself over time.
My energy consultant, for example, advised me a lot on detailed questions regarding insulation, thermal bridges, roller shutter boxes, etc. But also on the slope of window sills, questions about sealing materials, and so on.
He was basically my building surveyor.
You also get many contacts through the surrounding house builders. After all, they themselves needed all trades. So I was able to save almost 25k alone on windows and heating/plumbing.
For the next build, I will do plumbing/heating completely myself, as well as electrical installation. (Yes, an expert will then carry out the acceptance.)

And one more truly sincere tip! It is your money! And you alone decide what you pay to whom and how. Handle it carefully and consciously, and your house will be significantly cheaper despite high quality.

I still have to weigh that up ... something like, for example, the remaining excavation – if the architect hadn’t told me about it and taken care of it, I would have spent the saved 10k € elsewhere on disposal and landfill. Just as an example. I don’t know if I might be able to save even more through his good contacts with craftsmen ... and, as I said, if something really does come up, you still have an anchor ... he’s really a good guy you can reliably count on. But thanks for the suggestion, as I said, I’ve already heard that from several people and will continue to think it over. :-)