Unknown Craw Space

[Kurt Key]

Hello BP!

I got an offer accepted for a single-fam that will be converted into a duplex here in Cincinnati and while going through the inspection we came across a big unknown. There was an addition to the home, which the home was originally built in 1891, and put on in 1997. There is no known access point to the crawl space and it is speculated that it is built upon a slab. However, there's a vent on the back side and there's no reason to have a vent if it was built on a slab, correct?

To add salt to the wound I tried contacting the previous owner who made the addition with no luck. I am trying to negotiate a credit for other issues, but is there anything else I could do to limit my liability on this if I can't get to look at the crawl space? Anything to negotiate for?

Thank you! 

[Bill B.]

Is it a pvc pipe and is there a constant flow out of the vent? It could be to reduce the radon level? There wouldn’t be any crawl space to have access to if it’s built on a slab. I would think your inspector could tell you if it’s on slab or not. Certainly any foundation guy could. 

Is there a reason you care one way or the other? It sounds like it’s been fine for 30 years. Can you research the permit and maybe see some plans?