Problems with two separated basements in house

I recently purchased a house with two separated basements. The previous owner added an addition to the house and in doing so, created an additional basement instead of expanding the old basement. The old basement has only one entrance and that is from the outside (it also has the water heater, furnace, and fuse box). The new basement has two entrances: one from the outside and one from a stairwell from inside of the house (and it is carpeted).

The two basements each have their own four concrete walls, appear to have similar height, and are separated by a crawl space that is about 4 feet wide and 4 feet high that runs all the way between the two basements. I was interested in connecting the basements so that I could have access to the old basement from inside the house, but there seems to be some obstacles. First, there is a pipe coming down from the upstairs bathroom going in between. Also, there is about 4 feet high of dirt in between the two basements (I don't know if there is hardrock under the dirt). Can these obstacles be overcome? And if so, what would be the approximate cost? Would the cost be worth it? Also, each basement has an entrance from the outside that almost always allows water in during heavy rainstorms. Any thoughts?

 

This can be done, but since you had to ask, this project is beyond your DIY skills.

It takes special equipment to cut the foundation walls. The diamond blades are very expensive. If you could rent a cutter and broke the blade, you'd have spent way more than the cost of hiring the pro.

You have to make sure the walls are supported before, during, after the doorways are installed.

Then there's the problem of getting a good waterproof seal between the the existing foundations and the "hallway".

As for the existing flooding - where does the water come from? ie) how is it coming in by the exterior doors or thru the walls?

 

I would get at least 3 estimates from three foundation specialists and pick their brains about how they would proceed. Then, I would determine if it was within my budget to hire someone or if I wanted to tackle the job myself. The major concern here is doing anything to disturb an existing foundation. My research indicates that it is not a good thing to disturb a happy foundation. If you find someone who is willing to do what you want, then is there a warranty or some recourse if the house or foundation should decide to develop problems or fall in? Will all the expense and trouble add any value to your home when it comes to resale value? This is an important factor.

 

First, I realize I won't be able to do this by myself. The contractors that I have contacted say this is too small a job and that I should talk with some local handymen. I have since done so and have brought a few out to see the situation. They haven't commented on the potential problem of the hardrock between the two basements and haven't given me a rough estimate, although I'm thinking in the range of less than $2,000. Is this realistic? Also, when the issue of permits comes in, the handymen that I have spoken with get all nervous and say I need to contact a county building inspector first before proceeding. I have also started considering an option of putting in a stairwell from the upstairs to the old basement.

As for the flooding, there are small drains just outside each basement door that are the problem. The drains each have openings that are about the size of a quarter and get clogged by the tiniest leaf. I am looking into putting up a mini roof that could extend 5 feet out from the door to help divert the water.