Adding a basement?

KayJay · #1 10/15/07, 12:09 PM

So this might be a naive question, but I figured if anyone could answer it for me it'd be you wonderful HT people.

I was wondering if it is possible to add a basement to an already existing house, and if so, is it usually worth it or would it probably cost too much?
I ask because we ended up buying a smaller house with less property than we wanted because we couldn't wait any longer for the place we wanted to be ready. We really would like to add an extra bedroom because we have a son and a daughter and only 2 bedrooms, but we don't want to take away any more land from the little 2 acres we have, so I was thinking a basement might be the way to go....
This will be a couple years in the making, but I'd like to get as many ideas as possible. So please, feel free to share any!

wy_white_wolf · #2 10/15/07, 12:24 PM

It can be done but is usually cheaper and easier to add a second story if you don't already have it and the foundation will support it.

3 ways I've heard of doing it:

1. Jack up and support the house like a mover would while you dig out and pour a new foundation and basement walls. Some have just moved the house out of the way. Never known anyone to live in the house while doing this.

2. Do 1 wall or section at a time. Dig out and do like a 20' section at a time. You can live in the house but real care has to be taken doing it this way. If you have a high water table these basements seem to leak at the seams.

3. If it has a 4' deep foundation. Jack the house up 4' and build a stem wall making it a daylight basement. Need to move out during the jacking and buildingh stage but can move back in and finish it at your own pace.

Billie in MO · #3 10/15/07, 12:34 PM

Quote:

Originally Posted by wy_white_wolf

2. Do 1 wall or section at a time. Dig out and do like a 20' section at a time. You can live in the house but real care has to be taken doing it this way. If you have a high water table these basements seem to leak at the seams.
.

My dad knew someone that he used to work with who did this. He rigged up a pulley system for buckets to move the dirt out so he didn't have to climb out each time to empty the buckets. This took place back in the late 1960's.

wildhorse · #4 10/15/07, 12:39 PM

I wouldn't recommend it our house has a basement added and its a mess.

Kevingr · #5 10/15/07, 01:22 PM

People do that around here (central MN) or move a house in and build the foundation under it. Most of the people who do it have old farm houses with leaky stone basements and they want to upgrade. Depending on the situation and what type of walls you have put up (plain old block, poured, insulated and ready to finish the basement, egress windows etc etc) it can cost anywhere from $25,000 to $45,000 for a typical 1000 square foot house. We had an estimate of $32,000 for our two story house that has a stone basement. We still haven't decided if we're going to stay here long term or not, if your just going to stay there short term it's not worth the expense, but if you plan on staying I believe it's a good option to add square footage.

Maura · #6 10/15/07, 06:01 PM

I've known people do do that. You could also build the basement on level ground, put the house up, then bank up the sides so you have a walk out basement (or two story house on a slab).

oberhaslikid · #7 10/15/07, 07:29 PM

We did it to our house when we bought it the foundation stone had crumbled under the house .It was setting on the ground on one side.We took the front porch off and started digging, dug out one side and put jacks and 10x10 beams to support the house then started building the basement on that side built up to the height wanted then started digging out the other side and as we jacked up that side let the other side down on the basement.Then built the back and the other side met in the middle of the back wall then let the house down on the other side.The front is all wood with a man door and a garage door.

KayJay · #8 10/15/07, 08:03 PM

Thanks for the replies, guys. We would like to move to more property eventually, but want to explore options in case we aren't able to. Costwise though (from Kevingr's estimate), I'm thinking it'd probably be better to buy a piece of land and put in a mobile home or cabin, that way we could sell this and end up with more land and more bedrooms, lol. Keep the ideas coming though, I like to keep my options open.