great insights based on your extensive experience @Holly Williams 

They simply didn't want the property anymore due to the extensive legal issues that came with it and their father's past.

You need to vet them extensively. 

You can also ask for a loan extension which you should do.  

If you are using a standard CA sales agreement, you probably have your loan contingency in place still.Your realtor should be working on asking for an extension to buy you time.

@Jason Graveshttps://www.kcur.org/post/kansas-city-streetcar-extension-plan-umkc-wins-key-support-federal-agency#stream/0

We are wondering if we add an extension to the house what type of permits would we have to get and possibly if anyone is familiar with how much the permit(s) may cost in the Sacramento area.

-Costs of street development and utility extensions (public water and septic)-Approval process for subdividing, what should I make contract contingent on to protect myself (approvals, soil tests, stormwater etc)-Is there a form of financing people generally use?

@James Wright the last two we have done (one is currently in process the other just closed 60 days ago) both were 4.75% 5 year initial term, 5 year extension, with a cap of 5.25%. 

Many of these issues come about due to not filing the proper termination form or extension requests.