Costs of trades for interior finishing - is a construction manager advisable?

Hello, our general contractor disappeared after completing the shell construction, even though we had already paid him over 70% of the fixed price. Now we have to finish building our house (semi-detached house, 180m2, basement/ground floor/upper floor/attic) ourselves and are wondering what costs will still come up. We already have quotes for various trades: electrical €13,000, heating and plumbing (including LWW pump) €50,000, drywalling in the attic €16,000, interior and exterior plaster €24,000. Are these prices reasonable (we are building in the southeast of Munich)? What other costs will we face, e.g. screed, doors, floor coverings, stairs, interior window sills, etc.? Of course, I know that it always depends on what you choose, but maybe there are some guidelines so that we can prepare for the additional costs. Perhaps someone has been in the same situation. Is it advisable to hire an independent construction manager? Thanks for your answers.

Hello, our general contractor disappeared after completing the shell of the building, even though we had already paid him over 70% of the fixed price. Now we have to finish building our house (semi-detached house, 180m2, basement/ground floor/upper floor/attic) ourselves and are wondering what costs are still to come. We already have quotes for various trades: Electrical €13,000, heating and plumbing (including LWW pump) €50,000, drywall in the attic €16,000, interior and exterior plaster €24,000. Are these prices reasonable (we are building in the southeast of Munich)? What other costs can we expect, e.g. screed, doors, floor coverings, stairs, interior window sills, etc.? Of course, I know it always depends on what you choose, but maybe there are some guidelines so we can prepare for the additional costs. Maybe someone else was in the same situation. Is it advisable to get an independent construction manager? Thanks for your answers.

Hello

Did you have a construction contract and itemized trades? That gives you roughly the developer price. What does your bank say about it?

I would involve an expert who manages all of this....

Hello, what is a construction contract? The trades were not really itemized. We have paid according to the construction progress, but indeed too much in relation to the work performed. Depending on how much the completion of the house still costs, we will need to take out an additional loan.