We are building our own nest - the way & report into the house

Sounds good & reasonable.
Take a close look at what is not included in the price.

Floors: From €2000 (laminate in [EL]) up to easily €25,000, everything is possible.
Wallpapering + painting walls: In [EL] maybe €3000 (but plan for 3 weeks off), if done professionally certainly €10,000-15,000.
Earthworks: Impossible to estimate, but definitely five figures.
Outdoor facilities: €10,000-25,000 go quickly. The €10,000 applies in [EL]. Terraces, entrance podium, access paths, splash protection strip, lawn...

Of course, also look at what is included in the price. Which heating system (running costs), ventilation system, electric shutters, underfloor heating (should be standard), number of sockets/switches, etc.

Sounds good & reasonable. Take a close look at what is not included in the price. Floors: From 2000€ (laminate in EL) up to easily 25,000€ everything is possible. Wallpapering walls + painting: In EL maybe 3000 euros (but plan 3 weeks vacation), if you have it done certainly 10-15,000€ Earthworks: Impossible to calculate, but certainly five figures Outdoor facilities: 10-25,000€ quickly gone. The 10,000 are in EL. Terraces, entrance platform, access path, splash protection strip, lawn... Of course also look at what is included in the price. Which heating (running costs), ventilation system, electric shutters, underfloor heating (should be standard), number of sockets/switches, etc.

As soon as everything is open, I will present it here transparently. This way people who probably all start like us and of course we benefit from it.

The cost estimate we have is 255,000€ turnkey with foundation slab. For 132.32 square meters.

Who offered that? A general contractor? Do you have his construction service description?

Does anyone here have a floor plan for a bungalow or an idea where I can find one for 4 people with possibly a small office?

That is what the architect is for. With a general contractor or construction manager, a design is included in the price.

Who offered that? A general contractor (GU)? Do you have his scope of work?

That's what the architect is for. With a GU or subcontractor (BU), a design is included in the price.

We met the gentleman at the model home. His business card lists him as a sales representative and sales office manager. Whether he is a BU or GU is a good question.

We received the offer at the model home. I suspect he is a GU; we would take the construction from Bien-Zenker, and he would commission the rest regionally. Attached is the table with the breakdown. We were also told everything is according to building services; we can propose alternative trades if it is cheaper or reduce the material price by providing the materials ourselves.

We received the offer in the show house. I assume he is the general contractor; we would take the construction from Bien-Zenker, the rest he would commission regionally. Attached is the table with the breakdown. We were also told everything according to building services engineering, we can suggest alternative trades if it is cheaper or also reduce the material price by providing the material ourselves.

But that is a 110m² house (net floor area).

But that is a 110m² house (NGF).

Yes, that's right, we are now calculating a slightly larger one with an additional room.