So, I gird my loins, grab a flashlight and enter the crawlspace of chez Carcosa to do a little work. It occurs to me that I never noticed how much headroom I have there – approx 4 to 4.5 feet – and I started to wonder what it would take to dig this out enough to make an actual basement. Anyone try this? Who would you contact to perform this type of job? What would it cost?
Don’t do it. It will cause more problems than it will solve. The expenses involved will almost never be recouped upon selling your house because the market value it adds is, except for a few rare cases, nothing. If you want to add space to your house do it 100% above ground. The reason for this is because all real estate appraiser use ANSI standards and ANSI standards stipulate that any space that isn’t 100% above grade can’t be used as gross living space to determine value.
Why does that matter?
The people buying your house will probably finance it. If they pay more than can be demonstrated by the appraiser no one will finance it.
er… by that logic, no house with a basement would ever sell.
In my experience, it’s finished square footage that counts towards the appraisal, not what’s above ground or below ground. You can add value to your home by finishing off the basement, for example.
You Jerk!
Actually, if you had said the cost of shoring up the foundation may outweigh any gains in usable space, much like these guys did :Builder’s Websource
then you would have had a case.
Obviously, though, you are unfamilar with the Troglodytes who live in their parent’s basement till some undefined year of their life…
Basements are funny things.
In some parts of the US, all houses have them and a house without one is very hard to sell. The basement may not be in the appraisal square footage, but an otherwise idenitcal house with no basement at all will appraise lower.
In other parts of the country, basements are unheard of and nobody would expect a house to have one. An appraiser might not even be able to recognize the existence of one, or know how to rpice it if they did recognize it.
I suspect the above posters are from differing parts of the country and brought their unstated assumptions into the fray.
I think the question concerned what it would take to do the job, rather than dubious uses of ANSI standards and appraisal opinions which don’t apply in any event. If your crawlspace is already 4 feet or so below the outside grade, you can pretty much count on the footings for the building being right at or very near the level of the crawlspace floor. If you wish to dig deeper, do a little selective excavation and dig a hole along one side of the foundation, just deep enough to expose the top of the footing. (The footing will be the part of the basement wall that juts out towards you suddenly.) From the top of this protrusion, draw a 45 degree angle inwards (into the space you want to excavate), and the area that remains inside this projection can be excavated without undermining the foundation and collapsing the house. You can’t dig straight down, or the building will fall down. That is the sort of thing that gets your name in the paper.
Gairloch.
We lived in a house that had 3/4 slab and 1/4 basement. Getting the basement dug from under the house would have been a very expensive undertaking. As it turns out, you just can’t get under there with a shovel and go to town. Here’s what’s involved (for us at least):
- Dig out about 2 ft more than necessary to get equipment in/out
- Relocate water lines (clean and septic)
- Relocate mechanics (hot water, heat…)
- Lift house (harder than it sounds)
- After digging, pour footers, floor, build basement walls with correct drainage.
- Set the house on top of the new basement
- Make an entry way from upstairs to downstairs, usually through a closet so it doesn’t distrurb the floor plan
Mind you, this house was on a concrete slab with hot water heating through the floors and the house had paster walls, so moving the house in such a way to minimize the damage would have been tricky.
Even though a basement in my area is an important feature, we would not have recouped the cost. For the same money, we could have built a nice addition, with a basement. If you’re looking for more space, you may want to consider that route.
Thanks for the answers. I was afraid that retrofitting a basement would be cost prohibitive. Just seems like an awful waste of space. Maybe I’ll just plan it out as a long term project.
Aha! I considered this! I thought about building an extension perpindicular to the house that would have a large formal dining room on top (second floor), a library and billiard room (first floor), and then a basement.
Guess I’ll check out my addition options first and crawlspace options later.
FWIW check the water table while you are at it. If during the rainy season the water table rises to within say a foot of the surface, a basement can become an indoor swimming pool.