My Petworth rowhouse has one, and it's not at all unusual. 

(Which is not unusual, so don't feel bad.)The Solo 401(k) has very powerful contribution capacity for either tax-deferred or Roth tax treatment.  

I want to make sure I'm not overlooking any potential risks or unusual requests in this counter offer.Thank you in advance for your help!

This is an unusual scenario, however.

If the bathroom being in a basement is unusual for this neighborhood, then the rehab costs will likely go up in order to finish the basement.

You don't occupy the property so the DF Act appears to apply to your deal.Sub-2 is your arrangement to utilize now. 30% down is unusual in SF deals overall, 20% is usually the goal, many are down at 10%. :)

I mean the challenge is in complying with them with an unusual structure. 

. :-)The situation is a bit unusual, perhaps the devil is in the details : The original owners who signed the contract owned 2 buildings on 2 adjacent lots.

Im looking at a house that has an unusual shape.

@Rob Chopra if they didn't do anything more than their original quote, yes, that would be unusual.