If you're worried about hurting your friend's feelings, offer to have him refer you out to another agent and he'll get 25% of that commission.Anyway, enough of my pessimistic soap box. 

Yale Assure with the wi-fi connecter/box inside, is our first choice!

Before you commit to building it out of wood and wallboard you could always mock it up using cardboard boxes cut up into sheets with duct tape to hold them together.

In every metric of value US is declining but hey, were super diverse, kids can identify as a furry and schools are putting litter boxs in bathrooms for em yeah-us right. 

I like the out of the box type thinking, but I am not sure I would use it and how many people would versus the risk and maintenance aspect. 

If it was in bad shape already and her dog made it worse...I'd pay a larger percentage.Talk to a flooring company (not a big box store) and ask them what they'd recommend. 

I would do a city analysis based on your buy box and see which city pan out Just a suggestion and as always not written by Ai.

@Lesley Resnick Has some great points and an outside-the-box look at this.

You may have success with Multifamily DSCR Loans for 5-10 units - then really once you are at 11+ its going to be a whole additional/different set of lenders - commercial mortgage brokers probably your best search/bet if its significantly above 6 units in your buy box

Also, remember an RAL will likely be located in a residentially zoned area, not a commercial zoned area like a big box ALF would be.