Everything You Need to Know about Slab Basement for Houses

When a listing says the basement is a Slab, what does that mean?

I get asked often about what a "slab basement" is when it appears in search listings.  A Slab basement is another way to say that there is no basement.  The home was built on a "slab" of concrete, and that slab is the entire foundation.  

Why are some homes on a Slab Foundation?

There are many reasons that homes are built on slab concrete foundations without basements.  Here are some of the reasons:

• Soil doesn't support digging/basement construction.  In many parts of the country, there is very little dirt to put a foundation.  Some soils have too much clay or sand or are otherwise unstable to dig in, so instead they build on top of the surface with a slab foundation.
• Cost.  The builder may simply have been trying to reduce the cost of the construction.  Basements are very expensive to build, and are not always a profitable investment for the builder.
• Water.  If the house is close to the groundwater, digging a basement might just create a permanently wet basement.  In those cases, it is better not to dig at all, and just build on a slab of concrete. 

I'm sure there are others, but those would be the most common.  Whatever the reason, it should be noted that fixing such a thing is generally not practical.  Although slab basements are far less common in New England, in other parts of the country they are the dominant choice, showing that they can be fine houses just as they are - perhaps with a bit less storage. 

Are there special things about homes with Slab Concrete Foundations?

There are a couple.  Obviously, your heating and cooling equipment won't be in the basement, and is often somewhere on the first floor, where it can be noisy. So check out where the equipment is.  Some homes today would put the equipment in the attic, and that reduces the noise factor.  Also, it's important to check for termites with slab homes, as often the sill of the home is quite close to ground level, and termites can be harder to spot if the home exterior sheathing is close to ground level. Lastly, if the home has forced hot water, check to see if the plumbing is buried in the slab.  Concrete and copper are not friends, and the pipes often leak after a generation or two, forcing the house to be re-plumbed.  

Should I Buy a Home With a Slab Basement?

Sure!  No reason not to.  However, you shouldn't pay the same about of money for a home with a slab basement as you would for a home with a typical basement - at least in areas where the majority of the homes have a basement!  Buyers prefer basements, if they can get them, and giving them up means your average buyer will pay less for the house.  Often significantly!  In a soft market, a slab basement could reduce the sale price of the house 10-15% from similar homes with full basements.