Making offer, recent code violation notice - risks, strategies? (Unpermitted ADU in Seattle)

[Chester Knapp]

Hoped I would have a better first post:

I am (was?) about to make an offer on a nicely updated home in Seattle with a nice accessory dwelling unit / mother in law apartment.  I intend to occupy the top level with my family, and rent out the bottom.  It is in an area that may potentially change to multifamily, opening up a path to convert to duplex.

However, a quick permit search prior to making an offer revealed that the owner had not received a single permit for any work conducted, and received a code violation notice for the ADU last week with compliance due in about 30 days. Here are my questions:

1) What are the risks at this point?
I'm assuming I would likely have to remove the stove and fridge to comply with single family code, and the go about the process of permitting an ADU the right way. How likely is it that I would then also have to bring other unpermitted work (unrelated to the ADU) up to code?

2) Assuming risks are reasonable, what is a good strategy if I follow through and make an offer?  
This is a 'hot home' with multiple bids and pre-inspections, and it is unlikely that any other buyers are aware of this information.  I am interested in the home, it fits my strategy very well, but I am in the situation of having to out-bid buyers who do not have this negative information. 

[Paul Weller]

If everything was built correctly than it may just take establishing the use since the ADU is permitted in the zone. Check this out...

http://www.seattle.gov/dpd/permits/permittypes/constructionestablishinguse/default.htm

If there are substantial modifications to the existing building that need to be completed than you may need a whole building permit...

http://www.seattle.gov/dpd/permits/permittypes/constructionaddalt/default.htm

It is hard to quantify the risks.  You could submit your offer contingent on inspection and then determine what is up to code and you could get costs to do this.  If your offer is accepted and then you find out that too much would be required to get it to code you could back out or have the seller do them.