Floor plan design, 2 full floors, approximately 130-140 sqm without basement

Dear people, after the general price increase, we have decided to reduce the house to approximately 120-125 sqm net. The current floor plan is about 140 sqm, but for financial and credit reasons we need to spend less. We will meet with the architect soon, but before that we have asked some acquaintances and friends of the architect for help. Please help us if you can. We wanted a living and dining room of about 35 sqm, kitchen about 8-9 sqm, stairs as small as possible but comfortable, guest WC without shower, utility room about 10 sqm (without basement), upstairs: bathroom with 2 sinks, bedroom without wardrobe but yes apartment 2 wardrobes and 2 not too small children's rooms in the southwest and southeast each with 2 windows. We are also in talks with construction companies, but they are looking for a preliminary project which we do not have, because initially we want to know approximately how much the construction would cost per square meter. We hope that due to the simple appearance of the house (without balconies, without bay windows) we can achieve the best possible price, so maybe we could get 5-7 square meters more. We have 2 small children and every square meter will be important to us. Sorry for the poor German, I am helping myself with Google Translator. Thanks in advance and best regards.

We are also in talks with construction companies, but they are looking for a preliminary project, which we do not have, because first we want to know approximately how much the construction would cost per square meter. [...] Sorry for the bad German, I am helping myself with Google Translator.

Oh, yes, the bad German from Google Translator. That is probably why I cannot imagine what is meant by the "preliminary project" that you do not have. Can you try to say that again in other words?

Easy to downsize before problems arise. Free yourself from fixed square meters. Write down exactly which furniture with which dimensions should go into the house. For example, bed 210x200 cm, wardrobe 4 m, distance around the bed 60 - 70 cm, etc. Have you planned 2 full floors?

Speculation: Preliminary project = preliminary planning? It is said to exist in DE as well, that some GCs do not want to start without plans, so they don't have their own drafting slaves under their yoke...

Good to downsize before problems arise. Let go of the fixed square meters. Write down exactly which furniture with which dimensions should go into the house. For example, bed 210x200 cm, wardrobe 4 m, clearance around the bed 60 - 70 cm, etc. Have you planned 2 full floors?

Thank you for your answer, yes, 2 full floors, my children will be 2 meters tall (and we are tall) :)

Assumption: preliminary project = pre-planning?
It is said to exist in Germany as well, that some general contractors do not want to start without plans, so they do not have their own draftsmen under their yoke...

Thanks for the correction :)
Pre-planning in Croatia must not change in important matters, therefore we need to know how much we build in sqm