Offer for a two-family house with a gable roof, 232 sqm

I am planning a two-family house with a developer (NRW/Gütersloh). The developer has built several houses in my residential area, for example the apartment building I currently live in. I consider the developer reliable and competent, which is why I have decided to place my inquiry with him. Since things are becoming more concrete now, I have also read up a bit here and would appreciate some opinions and assessments regarding my current offer.

Key data:

[*]Plot 672 sqm (I am currently in the final stages of acquiring the plot)
[*]House with gable roof (unfortunately, no two full floors are permitted due to regulations -> building inquiry was rejected). To give it a somewhat more modern look, I decided on a gable roof (smooth roof tiles) without overhang -> but with a clinker facade
[*]232 sqm living space (ground floor: 121, upper floor: 111). Both apartments have a larger open living area with open kitchen, bedroom, dressing room, bathroom, guest toilet, storage room, and another room (child/office).
[*]Full basement

The building specification provided by the developer is detailed and covers many pages, so here are just a few key points.

Heating:
Ground source/water heat pump Vaillant VWF for heating and hot water generation.
Weather- and time-controlled regulation.
Heat source: geothermal probe
Underfloor heating throughout the ground and upper floors controlled via room thermostats with electrothermal actuators.

Floor coverings
Tiles in the entrance area, kitchen, corridors, storage rooms, bathrooms, WC including tile skirting. The basement corridor, technical, laundry/drying basement rooms are also tiled.
Floor coverings in the remaining rooms are not included in the scope of services.

Wall tiles
Bathroom, WC: tiled 1.20 m high, in shower area up to ceiling height

Painting work
The staircase is finished with roll plaster and painted with polysatin paint in off-white.
All basement rooms receive an opaque coat of dispersion paint.

Satellite reception system and connections in the living rooms. Network/network connections in the living rooms.

Lift/slide door to terrace/balcony on ground and upper floor (larger element per apartment -> 5.50 m).

Energy Saving Ordinance calculation: 40.96 kWh/(m²a)

The fixed-price offer for the above points by the developer is 455,000 euros.

According to the developer, I should roughly include the following additional costs in my calculation:

Garage approx.: €9,800
Storage shed approx.: €4,500
Rainwater/sewage channel approx.: €6,500
Paving work approx.: €15,000
House connections approx.: €5,000
Remaining floor coverings approx.: €11,500
Painting work in the apartments approx.: €10,000

At first glance, the offer for building the house for 455,000 euros seems reasonable to me. What are your opinions/assessments?

What about the electrical system? And is clinker and a 120 sqm basement included in the price?

Electricity is included in the price... additional charges may apply for more sockets, cable ducts, etc., but basically a basic electrical installation is included.

Electrical installation: The electrical installation is carried out according to VDE regulations. All flush-mounted lines are laid in empty conduits. A fuse box is installed in each apartment. One circuit breaker per apartment for garage, basement, washing machine, dryer, living rooms, kitchen, dishwasher, three circuit breakers for stove high current, one RCD (residual current device). A separate circuit for general power (heating, stairwell lighting, etc.). Basement rooms: Installation is mounted on the concrete walls. For masonry walls, the installation is flush-mounted. In all basement rooms, one light point and 2 sockets each. One socket each for washing machine, wastewater pump, and dryer. The following switches and sockets from Busch-Jaeger in white are installed: Stairwell: 1 light point per floor with push-button control and timer switch. Main entrance: 2 light points with 1 motion detector. Hallway: 1 light point with 3 switches (cross-switch), 3 sockets. Storage room: 1 light point with simple switch, 1 socket. Kitchen: 1 light point with simple switch, 1 switchable socket for kitchen lighting, 10 sockets, 1 stove connection socket, 1 dishwasher connection. Living room: 2 light points each with a changeover switch, 8 sockets. Terrace/balcony: 1 light point, 1 socket, both switchable, with indicator switch. Bedroom/children’s room/study: 1 light point with simple switch, 5 sockets. Dressing room: 1 light point with simple switch, 2 sockets. Bathroom, guest WC: 1 light point with simple switch, mirror lighting with separate switch, 2 sockets.

The full basement of approx. 120 sqm and the clinker brick are also included in the price. The clinker was included in the offer of 455,000 EUR with an extra charge of nearly 16,000 EUR.

Building description for the clinker: Clinker facade: facing bricks of choice, in normal format. Calculation basis 700 EUR / 1000 pcs. including VAT. The grouting is done afterwards. The insulation is made of 16 cm stone wool, WLG035 installed, 3 cm air layer, window reveals pre-glued with insulation strips.

Phew, without wanting to stretch it too far, I would say that sounds reasonable for now. I assume you made a list of everything needed for such a house so that a) you have everything together and b) you can see what is included in the price and what will be added. And whether it is within the limit. Earthworks are still missing, for example, which are usually a big chunk that is not included.

First of all, thank you for your feedback.

The earthworks are also included in the price.

Excerpt from the construction description:

The creation of the building application, drainage, heat demand, and structural documents are included in the price. Fees of the authorities (e.g. for the building application, building inspections, etc.) are not included in the price. The stakeout framework, site setup including a mobile toilet, site security, disposal of construction debris and waste, provision of construction electricity and construction water are part of the scope of services.

Earthworks:
The topsoil is excavated and stored on the side. If necessary, the groundwater will be lowered. The excavation pit will be dug, and the transport and disposal of excess sandy soil are included in the price. The later distribution of the topsoil belongs to the landscaping.

So actually, most of it is already included in the price. As described, floor coverings in the living rooms and painting work are still missing, as well as these points for rough planning:

Detached garage approx.: €9,800.00
Storage shed approx.: €4,500.00
Rainwater/sewage channel approx.: €6,500.00
Paving work approx.: €15,000.00
House connections approx.: €5,000.00
Remaining floor coverings approx.: €11,500.00
Painting work in the apartments approx.: €10,000.00

The building application has been completed and already paid for. The later building inspection of course is still pending.

Financially, it fits into my plans. I have left myself a buffer of about €30,000–40,000 in equity.

Do you have a soil survey report?

Topsoil does not have to mean complete. If you are building with a basement, a lot of earth will be generated. If the soil is contaminated, it MAY not be allowed to be used anymore.

Is geothermal drilling permitted? Possibly check with the lower water authority in advance. If it is a water protection area, different brine agents must be used.

House connections depend. Are you giving up gas because of geothermal energy or do you want it for cooking? Telekom costs 800€, electricity / water depending on the location on the property. Get an approximate length / distances to the connection point and call yourself.

Regards
Markus