House construction with extension or basement/hobby workshop

Hello dear house building forum,

We are currently planning to build a house. Unfortunately, the planning is difficult for us. I somehow always see a chicken - egg problem.
How expensive is the house? Hard to say without the plot.
How expensive can the plot be? Hard to say without knowing how expensive the house is.

Therefore, we are currently trying to estimate the costs.
We would like to build with a cellar as a hobby workshop. We have quite a fleet of machines that would like a proper home.

Extension or cellar for this reason, because we don’t want the dirt inside the house. Simply increasing the living space of the house is therefore not possible.

What we would like at least:

[*]heated (via the house central heating?)
[*]> ~50m²
[*]power connection (or three-phase current)
[*](partly) soundproofed/insulated

Cellar	Extension
Advantages	Advantages
[*]more garden [*]direct connection to the house [*]no issues with building distances [*]higher market value of the house? [*]climate buffer? [*]better sound insulation (for neighbors) [*]network technology can be centralized	[*]cheaper (?) [*]ground-level entrance [*]large gate/door [*]can possibly be built afterwards
Disadvantages	Disadvantages
[*]price [*]utility room in cellar costs extra [*]moisture and mold? [*]difficult situation with daylight [*]poor access options (always via narrow stairs) [*]bicycles have to go into the garage [*](possibly lifting station for wastewater necessary) [*](difficult soil could cause higher costs)	[*]less garden area [*]may not visually fit the house [*]burglary protection?

These are the pros and cons we are more or less certain about.
But some questions remain open:

[*]Foundation for extension? Ground slab or like a garage?
[*]Building distances also to be observed for extension?
[*]What is the difference (legally) between a garage and an extension?
[*]Extension heated via the house central heating? Can a utility room be outsourced into the extension, even if the extension is not directly connected to the main building?
[*]Costs? Is there a guideline on how the costs relate to each other? For example, with the same living space, does an extension usually cost only 80% of a cellar?

For a fleet of machines for the hobby, a heated extension is probably the smartest option. For cost calculation: write down your room program and look for model homes that correspond to it the most. See how many square meters you need and use the factor 1900/sqm for Northern Germany, 2100 for Southern Germany. However, this is only a rough estimate. If you don’t have a plot yet, building won’t happen until 2019/2020 anyway. You should be able to roughly calculate land prices based on the prices that prevail in your region. Additional construction costs are 35900 for simple land, 50000 for complicated land. Carport, outdoor facilities... just google or use the search function here in the forum.

Oh right: what is heated, with a floor slab. House technology belongs in the thermal envelope. Living rooms must not be placed on the boundary, garages can be.

That should answer all your questions. If not, keep asking.

[...]Look at how many square meters you need and take the factor 1900/sqm for Northern Germany, 2100 for Southern Germany. But this is only a guideline.

West Germany

If you don’t have a plot yet, building will anyway only be possible around 2019/2020. You should be able to roughly calculate land prices based on the prices prevailing in your region. Additional building costs for simple cases 35,900, for complicated land 50,000.
Carport, outdoor facilities... just google or use the forum search here.

Additional building costs?

Oh right: what is heated, with a concrete slab. Building technology belongs inside the thermal envelope.

Does the concrete slab then become "simpler" / cheaper because there is less weight to carry? (The extension is supposed to be only one story, probably flat roof)

Does that mean if the extension is separate from the house, it actually only works with two heaters?
Are there special heating solutions for small buildings? Or do you then use electric heating?

Habitable rooms are not allowed right on the boundary line, garages are.

That should answer all your questions. If not, keep asking

And do rooms become habitable by heating? Or by their use?
So if I use a huge double garage as a workshop, can I put it on the boundary line?

West Germany

Construction prices vary regionally... No idea if building is cheap or expensive where you are. You tell us
You must currently be devouring newspapers and the internet regarding construction and such

Additional construction costs?

Additional construction costs (earthworks, permits... just enter it in the search at the top right)

Is the base slab then "simpler" / cheaper because there is less weight to carry?

No

Does that mean that if the extension stands separate from the house, it basically only works with 2x heating? Are there special solutions for heating of small buildings? Or do you then use electric heating?

I believe what you are aiming for is an additional building. That is not simply possible everywhere. Not in a new residential area, but also not if the development plan or floor area ratio makes it impossible for you to build too much area.
Usually, an additional building like a garage has to be subordinate to the main building; with 50 sqm this is no longer entirely clear.

Possibly a building gap in a rural area, if not even an existing building.
I also think you are not quite clear about the costs. Just roughly 40-60,000 for heated rooms used only as a hobby, you don’t just have lying around.

What does your bank say about how much financing you can even raise???

And do rooms become living spaces through heating? Or through their use? If I use a giant double garage as a workshop, can I then build it right on the boundary?

By use! But also how and if the outbuilding is connected to the main house... somehow... you have to check...
A giant garage must first be approved before you get to paying. I don’t want to be too blunt, but if you ask the "chicken-egg" question here in the forum, you won’t be able to pay for everything just like that.

AHA! Now I am a bit wiser

As I see it, I basically have no choice but to build a fully functional residential building as an extension. So there is no such thing as a halfway between a living room and a garage. Either I can live in it or it is cold in winter?

Well, I fear that in this case a basement wouldn’t even be more expensive than an extension. Instead of a 9x9m slab, I would need a 14x9m slab including earthworks. And the extension isn’t really much cheaper than living space if I basically have to fully finish it.

The payment is actually already arranged. I’m just trying to figure out how to allocate the money most efficiently for my needs. I would rather have 5m² more living space than have €5k left over at the end of the house construction. (I know, I know... that’s wishful thinking. But I hope it illustrates my idea.)

Einfach mal so 40-60000 für beheizbare Räume, die nur fürs Hobby dienen, hat man ja nicht mal so.

Exactly. That’s why I’m asking these silly questions.