There's lots  of easy value to be added in old housing  stock...space being underutilized....all perfect conditions for the BRRRR strategy. 

If I purchase a property this year and make payment to an architect and contractor towards capital improvements to the property, can these be added to my basis cost and offset the stock capital gains?  

Meaning additional load bearing beams/walls will need to be added to make up the difference for the hole cut in the floor ( if I understood you correctly).

Or could they legally be added to a lease amendment listing them as "occupants" then whatever happens - the original tenant is held liable?

In Chicago, there is a pretty well accepted and approved lease format, I'm not sure if that has the language, but it can be added as an addendum to the lease. 

Select your partners wisely - Realtor, Lender, 203k Consultant, and ContractorREALTOR - it's recommended to work with one that has done a 203k in the past so they know what verbiage HUD wants to be added to the purchase offer contract and how to structure the deal.Lender - advise you to select a lender with verified 203k experience; the lender is the quarterback in the process, controlling the rules, paperwork, processes, procedures, and if the lender does not have sufficient experience with the 203k, your entire process can look like the Cleveland Browns on a Sunday afternoon.203k Consultant - The 203k Consultant determines the scope of work and pricing for the project and inspects the completed work; the lender is responsible for selecting the 203k Consultant (refer to Lender paragraph above).

Lastly, if you would like to be added to the email distribution of this meetup, please send me a message with your email address.

In Seattle this means a 650 sq ft DADU, but no additional ADU's (unless the zoning permits more units, but either way that would be adding additional units, not a ADU, to a multifamily.)95% of garage conversions are done without permits and are not legal, especially if the property is multifamily.

In some municipalities, if the water bill is unpaid, the amount will be added to your property tax bill.

However, I am open to anything that gets me going in the right direction.I will defiantly be adding @Rob Drum to my reading list.I am very humbled to get a lunch offer so soon.