ᐅ Advice for a Semi-Detached House

Hello,

BTK27 schrieb:

Plot size 252 m2, unfortunately very expensive at 450 euros / m2, so not very large 🙂
max. build area: 6.5 m x 12 m

The plot is large enough for a semi-detached house; after all, the "land" also needs to be maintained.

BTK27 schrieb:

Current offer from a regional provider:
Semi-detached house with 6.5 x 10 m, 45-degree roof pitch
- Partial basement (30 m2). 16 m2 of the basement counts as living space and can be used as living area.
- Ground floor with shower in guest toilet, open kitchen, dining and living area (net 47 m2)
- Upper floor with large bathroom (12 m2), 2 rooms (net 46.5 m2)
- Attic (between the rafters) as living space with net 20 m2
- Heating/technical equipment: air heat pump with heat recovery, ventilation system

Around 267,000 euros including incidental building costs (except connections: electricity, water, telecom), tiled bathroom and toilet, "extras" already included except electrical work (e.g. some floor-to-ceiling windows, 2 dormers 1x 2 m, 1x 3 m with floor-to-ceiling windows)

This means you end up with about 128 sqm (square meters) of living space—not including the additional living space in the basement. My estimate:

Land: 113,400 euros
Single-family home, mid-standard (KfW 70): 192,500 euros
Central ventilation with heat recovery: 10,000 euros
Partial basement with partial living space: 40,000 euros
Incidental building costs: 35,000–40,000 euros
Painting work as self-performance: 10,000 euros
Floor coverings as self-performance: 10,000 euros
Exterior works as self-performance: 10,000 euros
Reserve for extras: 10,000 euros

This results in a total estimated investment of approximately 435,900 euros.

I do not know your provider; therefore, my estimate is based on a good standard with medium-level finishes. Whether this applies to your provider is something only you can decide.

BTK27 schrieb:

Our budget including self-performance and equity is 430,000 euros including everything: exterior works, carport, floor coverings, painting, kitchen

That will be quite tight, and there must be no extra foundation costs on the plot; the kitchen will probably remain wishful thinking, or the regular parking space will (initially) replace the carport 😉

BTK27 schrieb:

Is it reasonable, given the budget, to forego the basement or attic in favor of extending the house to 11 m to generate more living space?

The cost of the partial basement is disproportionate to its benefits, as you have probably already noticed. You will hardly be able to do without the attic even with a larger design; you will need the space. I generally advise against a partial basement—at least in cases where it can be avoided.

I would recommend making full use of the building envelope and completely skipping the basement. Here, we built a very nice semi-detached house on a slab foundation measuring 6.5 x 12.00 m for a family with 3 children at the time; after moving in, it quickly became 4 children (all boys) – but the room layout permits it. The semi-detached house is essentially developed up to the rafters—without feeling cramped and still offering storage space on the upper two floors... that is the hallmark of good preliminary planning... because the desire for children is by no means finished 😉

Regards, Bauexperte

Thank you for the replies.
@Bauexperte.
I’ve come to almost the same total (interesting 😀, I’ll have to give myself a pat on the back as a layman) – but this includes insurance as well as independent construction supervision.
Since the neighbor has already built with a basement, a support structure will be necessary. Our consultant mentioned that the costs wouldn’t be significantly lower without a basement :-)
– this remains to be questioned.
Is there any idea what extending to 12 m (39 feet) would cost, meaning a 2 m (8 feet) extension including materials, etc.?

As you can see, the main question is whether to extend the house for more living space or to build a basement for more "comfort"?

Here’s a brief floor plan of the ground floor at 6.5 x 10 m (21 x 33 feet). As I said, it looked small on paper. Of course, we don’t need a mansion either. 😎

... the pantry naturally takes up a lot of space from the kitchen, so the kitchen moves to the center of the house.
If you reduce the size of the bathroom and create a storage room in the "niche," while the hallway provides space for a wardrobe area (possibly next to the storage), you get a larger kitchen and can move the dining area to the center of the house.
Whether you need the wall in front of the stairs or just part of it as a partition is something you have to decide for yourself 🙂

Hello,

Are you allowed to build a one- or two-story house?

BTK27 schrieb:

Since the neighbor already has a basement, then some form of shoring is necessary. Our consultant said that the costs wouldn’t be significantly lower without a basement :-)
-- this remains to be questioned.

I consider that a rumor. If you have to build your foundation at your neighbor’s level due to their basement, logically their building’s structure must be supported. This will likely cost around EUR 8,000–10,000 (approximately USD 8,700–11,000), depending on the construction method and soil conditions. However, a partial basement—especially if partially finished as living space—costs roughly EUR 40,000 (around USD 43,500). With all due respect, your consultant seems more focused on their commission than what is actually best for you. Frankly, I don’t understand why they even mentioned a partial basement.

BTK27 schrieb:

Is there any idea about the price increase for extending the building to 12 m, meaning a 2 m extension including materials and so on?

I lied to you in my first post—sorry, that was unintentional—I simply remembered incorrectly. The floor plan for our clients that I mentioned measures 6.50 m x 11.50 m (21 ft 4 in x 37 ft 8 in) exterior dimensions. I’ve attached the ground floor plan, a section drawing, and two photos from just before completion. Overall, the net building footprint is 208.50 square meters (2245 square feet); of course, the actual living area is less.

BTK27 schrieb:

As you can see, the core question is house extension for more living space versus basement for increased “comfort”?

For comparison: the attached floor plan required an investment of approximately EUR 240,000 (around USD 260,000) as a KfW 70 efficiency house with an air-to-water heat pump, decentralized ventilation, electric shutters on the ground floor, partly colored facade, and colored window frames.

BTK27 schrieb:

Here is the ground floor plan at 6.5 x 10 m (21 ft 4 in x 32 ft 10 in). As I said, on paper it felt small. But of course, we don’t need a palace either. 😎

This floor plan was created carelessly with VI; just my two cents 😀

Best regards,
Bauexperte

Maybe someone can explain the situation with basements again. When is it considered living space and when is it not? What impact does this have on the calculation of living area? What are the disadvantages and advantages?

Good evening,

You haven’t had a proper consultation yet, have you?

BTK27 schrieb:

Would it be better to have two full floors with a larger footprint plus an attic, or just use the basement as a utility space, not as living space?

There’s hardly anything more expensive than building into the ground! And if you’re going for a basement at all, in my opinion only if it will be used as living space. Just my two cents 😉

BTK27 schrieb:

Could someone please explain the situation with the basement again?
When does it count as living space and when does it not? What impact does this have on the calculation of the living area?
What are the disadvantages/advantages?

The basement only counts as living area if it contains rooms that are developed for residential purposes; in your case the 16 sqm (172 sq ft), the rest is utility space.

Regards, Bauexperte