Which structural shell company to choose?

Hello everyone,

we want to start the shell construction in March 2021. The building is in BaWü and for the basement + 1 full floor + knee wall floor, we have shortlisted two construction companies through a known architect based on the received tender prices.

The tender was based on a fixed price. According to acquaintances, construction companies always hide a certain (fear/error) buffer of several thousand euros somewhere in their offers in case something unforeseen happens during construction, so that the site does not become a loss-making project for them.

Since our second child is due in February (parental leave), I intend to help a lot with the shell construction. Therefore, we are now considering moving away from the fixed price and building on an hourly basis with one of the two companies. But with which one?

Company A has a price of 214,000 EUR and Company B 227,000 EUR.
In Company A, the price for ground and masonry work is almost 40,000 EUR more expensive than in Company B (material + labor costs). However, Company B has significantly higher site setup costs and also a higher hourly wage (which would probably be important for hourly/time-based work).
What questions would you ask in the conversation with the two construction companies to make the right decision afterward? The companies will hardly admit in which position they have built in their buffer.

I almost think that with Company A I might manage to get a lower price with good cooperation because:
a) low site setup costs, which are always fixed anyway
b) lower hourly wage

You simply do not know how much of the almost 40,000 EUR difference in the ground and masonry work is material and how much is hourly rates. Hm, can you give tips?

Which items (besides hourly wages) would you look at if you now want to build on time/hourly basis instead of fixed price?

Many thanks for your suggestions.

Which positions (besides hourly wage) would you look at if you now want to rely on time/management instead of a fixed price?

Hourly wages are always a problematic area. I would categorically exclude them for myself when building a house. What do you think, how much time the craftsmen suddenly have? You can hardly build more expensively than by hourly wage.

Does this mean that you wouldn’t rely on a management / hourly basis?

Hmm, but if I accept the fixed price, then I can’t compensate my contribution of 20-40 hours per week, right?

The first question you have to ask is whether the companies even accept you as an assistant. And the next question is, does it actually bring profit?
What exactly do you want to contribute? What do you have in mind?
I mean, I've done it too. One master, three journeymen, and three guys who worked as assistants. But it’s not just that simple. And it’s difficult on your own.

I had my electricians on an hourly basis. Top work, quick guys.
I always paid the advances immediately, and in the end, everyone got a fifty. But you don’t know that beforehand.

Your mentioned criteria are simply too few for a really good decision. Which one gives you a better gut feeling? Are both local or is one further away? Who shows more interest in your project? How do they respond to your wishes? Who has the better local references? Who has the more satisfied-looking employees? What is the tone of communication? Whoever only looks at the money gets only what they pay for. Don’t make a soulless deal out of it or do you want to live in a soulless building?

And the next question is, does it actually bring profit? What exactly do you want to contribute? What do you envision?

Replacing a laborer. Assuming the construction site lasts 8 weeks. The laborer costs a flat rate of 50 EUR per hour. Then I already save a five-figure sum, don't I?

hamsphire, yes, those are all interesting questions. Both companies are very close (less than 20 km). I want to have talks with both bosses in the summer, but so far I can't think of a really revealing question.