Make the split-level floor smaller than the entrance level in new construction?

[Harry_k]

Hello, I would appreciate some tips and advice.

In our case, we are planning to build a new house with two floors comprising a basement and a ground floor. What do you think about making the basement 10m x 8m and the ground floor 10m x 12m? I imagine it might be more expensive and especially more troublesome from a construction perspective compared to making both floors the same size.

If we choose to make both floors the same size, the extra 40m2 will be used to create a hobby room and a storage space without windows, so those are relatively inexpensive areas to finish.
Slab on grade and walls of thermomur, so the additional heating cost should be minimal.

Should we save and build smaller or make both floors the same size? Grateful for advice.

 

[Pin]

I'm annoyed that the person who built my house didn't complete the entire lower floor. I'm missing these 30 m2 that could have been a workshop and storage.
Go for maximum space unless it becomes very expensive.

 

[Harry_k]

As the architect has designed it, we actually have enough space with the slightly smaller basement level. But it would be a shame to regret it afterwards.
Does anyone have experience building a smaller basement level and a larger upper floor?
It will mean another slab on the ground with a lot of filling material and the risk of settlements. Do you need to make the slab (40 m2) on the entrance level self-supporting, or is it sufficient to be meticulous with compacting the fill material?

 

[KnockOnWood]

I am annoyed that the person who built my house didn't build the entire lower floor. I am missing those 30 m2 that could have been a workshop and storage. Go for maximum area unless it becomes very expensive.

Agree!
Our previous house was 1½-story with a basement, size 10 x 8 m on both lower floors.
And the inner part of the basement was a guest room without windows (very quiet and peaceful)
as well as a storage/workshop where everything fit, including a freezer chest. Priceless square meters!

 

[bossespecial]

As the architect has designed, we actually have enough space with the slightly smaller basement level. But it would be a shame if one regrets it afterward. Does anyone have experience building a smaller basement level and a larger upper floor? It becomes an additional slab on the ground with much fill material and a risk of settling. Must you even make the slab (40 m2) on the entrance level self-supporting, or is it enough to be meticulous with "tamping" the fill material?

It's very difficult to achieve a well-packed foundation next to the basement wall. Therefore, the slab is usually made self-supporting at least as long as the basement wall is high. Another aspect to consider is future maintenance, such as draining the basement without undermining the slab on the ground. Moreover, the guidelines regarding thermomuren on Jackson's website do not rely on any packing pressure against the basement wall. If you pack, the walls become a bit more complicated than what's presented on the website.

 

[KnockOnWood]

And speaking of basement walls:
When we bought our previous house (built in 1969) in 1998, the inspector scratched his head and wondered why his moisture meter wasn't sounding the alarm down there. It should be damp!
But then we went outside, and he saw the pattern from the casting mold's planks.
Aha, it's cast-in-place, that explains the good moisture readings, he said approximately

So building with Leca blocks or gråsuggor probably results in a much more moisture-sensitive construction.

 

[bossespecial]

And speaking of basement walls: When we bought our last house (built in 1969) in 1998, the inspector scratched his head and wondered why his moisture meter wasn't alerting down there. It should be damp! But then we went outside, and he saw the pattern from the casting mold's planks. Aha, it's cast-in-place, that explains the good moisture levels, he said roughly So building with lecablock or gray squirrels probably results in a much more moisture-sensitive construction.

Cast-in-place is the thing The Thermoblocks are also cast walls where the blocks themselves are the casting form.

 

[Harry_k]

Yes, it certainly feels like solid walls are a good solution!
It sounds like it might be a good idea to go full size on the suterräng. The material cost will be somewhat higher, but from a purely construction engineering perspective, you might save some time and avoid certain calculations to make the entrance slab self-supporting.

 

[twoody]

Depends a bit on how the plot is, I have built with both equally large and smaller basement levels, and the difference was more reinforcement in the slab.

 

[Harry_k]

It depends a bit on how the plot is, I've built both with equally large split-level and smaller, and the difference was more reinforcement in the slab.

In other words, you wouldn't say that one construction technique was more troublesome than the other?

 

[justusandersson]

Split-level houses have certain general problems. It is not obviously the best solution when building on a slope. If you have plenty of space, it is often better to build only the upper part and partially support it on columns. If you want or need to build a lower level, there is nothing to say that the upper level needs to be the same size. It can be larger or smaller.

 

[Harry_k]

Split-level houses have certain general problems. It's not necessarily the best solution when building on a slope. If you have plenty of space, it's often better to just build the upper part and partially foundation it on pillars. If you want or need to build a split-level floor, there's nothing that says the upper floor needs to be the same size. It can be larger or smaller.

In our case, we are limited by a narrow plot. A single-story villa would become too long and narrow for our taste, with the view facing one of the short sides. But I understand your thinking.

 

[justusandersson]

It is always beneficial to broaden perspectives. Much of the issues are location-specific: topography, type of subsoil, cardinal directions, zoning plan, etc.

 

[Jensa86]

I have a three-story split-level house where the middle floor is the smallest

But that's mostly because it has been extended several times and wasn't like that originally. Originally, it was two split-level floors that were the same size. Then, over time, more was built on. First, an extra floor was added which became larger, and then an expansion was done in the part of the split-level floor that was above ground. It's a bit special with many odd corners and edges, but it has its charm too. It might not be something to strive for if you get to build new.

 

[Harry_k]

Fun with some different solutions, everything works as long as you build it right.