Build basement

[Felix36]

Thinking about building a basement in my new undeveloped house. What would a basement cost, "rough estimate" compared to making a slab on the ground?
Base plate, walls, external protection that comes when you don't cast a slab on the ground, filling, etc.
Thanks for the help and take care!

 

[saiter]

Depends on who does the job.
You need a slab anyway.
If it's good ground and just a matter of digging and walling, maybe 100,000 SEK is enough.
Depends on the size too.

What does your plot look like?

//AA

 

[Thomas_Blekinge]

A basement is invaluable! Better a basement for an extra 150k (if that is enough) than an over-styled kitchen that will still be outdated in 10 years.

 

[Felix36]

True, true, but I was thinking of hiring a company to help me. I have a friend who has a company, so maybe I can get a better price... ☺️
Is it a 30 or 40cm thick slab that you need for a "basement floor"?
It's moraine ground here, so it's fairly easy to dig as long as you don't hit rock... the base slab will be 110sqm.
Take care!

Depends on who does the job.
You still need a slab.
If it's good ground and just digging and masonry, maybe 100,000kr is enough.
Also depends on the size.

What does your plot look like?

//AA

 

[saiter]

Again, it depends.

If you want +20 degrees in the basement, just insulate.
30cm in that case.

Will it be a garage there?

What kind of house will be on top??

For basement outer walls you can use Leca for example, with foam inside.
Or shell blocks that you pour concrete into.

//AA

 

[Felix36]

Yes, it will be furnished with a laundry room, storage, etc., but no garage; it will be located on the ground some distance away from the upcoming house. The house on top will be 2 stories with full ceiling height on the upper floor. 2.70 on the lower floor and 2.40 on the upper floor. A total of 236 square meters over two floors. Do we need to pour a concrete floor, or can we have a wooden joist?

Again, it depends.

If you want +20 degrees in the basement, then you just need to insulate.
30 cm in that case.

Will there be a garage there?

What kind of house will be on top??

For the outer walls in the basement, you can use Leca, for example, with insulation inside.
Or shell blocks that you pour concrete into.

//AA

 

[saiter]

Wooden joists work well.

Keep in mind that it is much easier with a full "hjärtvägg."
Both in the basement and on the 1st floor.

//AA

 

[falkn]

Estimate roughly between 4-6' per m2 finished with surface layers etc. Do you need the masses from the basement for anything?
It affects quite a bit.

 

[Felix36]

Ok, good to have a benchmark..
There is room for some of the masses, but there is a risk that there are very large stones down in the ground that can be difficult to get rid of... dug for water and sewage 3 years ago and there were some really big ones that had to be brought up then..

Estimate roughly between 4-6’ per m2 finished with surface layers etc. Do you need the masses from the basement for something?
That affects a lot.

 

[flimsy]

We are building with a basement, however, it's a walkout basement, so it's enough to dig into the slope. We expect to have spent about 7,500 SEK / m2 when it's done. Perfect ground conditions = moraine and we will need the masses as fill on the plot. Transporting them away could easily add a significant extra cost if it's a long drive. Large boulders aren't a problem for the excavators; they can roll away the worst ones or break them if needed, but anything smaller than a dining table is manageable.

We would have needed to cast the slab in any case, and in our case, we're having a double garage in the basement, so for us, it turned out to be both a functional and economically good solution compared to building it separately!

Of course, this adds the cost for the wooden joist floor, which we wouldn't have needed if we had cast a regular slab on the ground.

 

[Felix36]

Are you embedding underfloor heating in the slab as well or how are you planning to heat the ground floor?

We are building with a basement, however, it's a hillside so it's enough to dig into the slope.
We expect to have spent about 7.5' / m2 when it's finished. Perfect ground conditions = moraine, and we will need the masses as fill on the plot. It can easily become a considerable extra cost if you have to transport away the masses and it's a long drive.
Large boulders are not a problem for the excavators, the most difficult are rolled away or shattered if necessary, but anything smaller than a dining table is fine.

We would have had to cast the slab anyway, and in our case, we will have a double garage in the basement, so for us, it became both a functional and economically good solution compared to building this separately!

Of course, the cost of the wood frame, which we wouldn't have needed if we had cast a regular slab on the ground, is added.

 

[flimsy]

Are you installing underfloor heating in the slab as well, or how will you heat the ground floor?

Underfloor heating

 

[saiter]

Yes, underfloor heating is not something to skimp on.

//AA