There’s 4-5 very similar properties (sq footage, bdr, bth etc) that have sold btw 613k - 699k and another pending around 715k.

In the meatime, I am focusing on best and highest use for my portfolio by adding bedrooms / square footage / ADUs to properties that I can anticipate both an equity and Cash flow bump.   

It we nice to have search criteria to include square footage so the system pulls more accurate comps.  

Do I need to mark down 50% as that is roughly the square footage of the entire home they rent?

Orem is an older city that has a different demographic of renter more of the blue collar workers, newly weds and college kids unless you go to Vineyard which is a "newer" part of Orem that has a ton of new development going on you'd be hard pressed to find anything in Vineyard under $300,000 as most homes are new and have a lot of square footage.

Wasn't able to find enough comps for what real estate sites are calling a 5 bedroom 3 bath house, but between square footage and bathrooms and 4 or 5 bedrooms. i suspect the ARV to be over $350,000

Taking some arbitrary figure like $15 per sq. ft. and multiplying by the square footage of the subject property is NOT how you properly or accurately calculate a renovation budget.

I did A LOT, all new systems, windows, doors, roof, etc.A few things I look for: hidden value, in this case it was adding on the sq footage, creating a really great master suite and also leveraging the views.

Please don't post your scenario in this thread, use this when making your own thread.Your goals and story: What are you trying to accomplish, how are you trying to accomplish it, and what hurdles (if any) have you faced.Type of property: Single family home, manufactured home, RV/trailer, multi-family (specify unit count), mixed use (specify resi v commercial unit counts and approximate square footage distribution between the two), hotel, casino, mobile home park, other (specify).Location of property: State at a minimum, county better, city would be nice, zip code if you're comfy sharing. 

Of course things like property taxes and mortgage interest you would have to allocate to the cottage based on some reasonable method (perhaps based on square footage) as well.Note that you actually have to be in the business of rental real estate before taking rental deductions, and that there may be some expenses you incur, e.g., to get a space rent-ready, that you must capitalize to the basis.