Costs for our house construction

Hi,

we're at it let's create of various providers of prefabricated houses offers (2 offers are already available, will follow two offers. Unfortunately we have no experience and can not estimate really whether the offers are legitimate. So I would appreciate if someone experiences and has the following projects could cost roughly estimate (only the costs for the house, grounds and we already have the cost of building application ...... we can estimate):

2 family house
A 110m2 two floors
passive House
Gable roof (hence the flat top can also be slightly smaller)
without basement
Includes EVERYTHING except install flooring (carpet, laminate, tiles), walls (painting, wallpapering), doors, bathroom
But everything else should be included, ie heating, floor plate, windows, gutters, electrical, gas, water up to the Bautoilette

Can someone estimate our costs? I am very confused and can compare the offers very bad, because one can never be sure if everything will cover, or whether we will see later surprises. As a layman, it is nearly impossible to know what everything should be provided to services.

Would be glad if I can help jamand. Thank you.

greeting

I would guess the best you can do is to look for contractors who have built similar houses and then make some cost/bid comparisons.

First, the cost could vary by 100% between let's say California, upstate NY, Kansas, Louisiana.
Honestly even knowing where you are, no one can estimate your house. A builder with a look at the plans, could give you some ballbark "per square foot" construction costs.
Given your inexperience, you would be very ill advised to try to be your own general contractor on this. The subs will eat your lunch. Want a change order? add two zeroes!

I suggest you research in your area who are the general contractors with the best reputation. Talk to them. Be comfortable that if they get your job, you will have daily access and contract to the foreman when necessary. Have them lay out in detail what is covered by the contract. Have your lawyer check the contract.

There is absolutely NO WAY to estimate the costs because EVERYTHING depends on several factors which we would need blueprints to determine. However, there was a company in Chicago which provided homes like this. After the contract was signed, they would tell the buyers, "We are not in that area so we will give you a $???.?? credit for you to install your own plumbing, $???.?? for the electrical, $???.?? for the heating, ditto for the drywall, cabinets, finish floors, and concrete basement floor. By the time they were done they paid ALMOST the full price for a "shell house", and most of them thought they got a "good deal". Most of them also tried to DIY finish the homes and most of them looked like it. we would set sinks in 2x4 frames, or hang them on stud walls, and the homeowners would use sheets to cover the walls for privacy.