Another consideration is the additional space per unit required to accommodate a laundry space. 

She knows Ronnie at the Wholesale furniture and linens store, sourced on line, planned the space, oversaw the whole job in matter of days. 

Let alone how competitive the market is here, they could just find another buyer.My big concern is that the property doesn't have central air and I would be installing that with ducts going through the attic (no crawlspace) immediately during the first month after closing.

@Sonia Chopra Jorge Fontan a architect here in NYC wrote a great Blog on when attics count as part of the Floor (living space) Area.This should help answer your question.https://fontanarchitecture.com...Cheers!

I'd encourage you to find a great mentor in the apartment space.

You can go to your local home depot and speak to them about your ideas on renovating/retrofitting your space, register as a contractor, it would save you a ton of money if you are buying yourself,  I am sure you can get someone competent and affordable to assist with your schematics, designs and cost.

They'll also be able to paint out a picture for you on how to execute your goals and assist with a strategy (Maybe not family and friends, unless they have experience in the space). 

Key in that latter space is to thoroughly vet tenants so that you have at least B+ tenants renting C/D doors.

Today I'd like to discuss the value of public spaces.

I reckon that type of decision comes into play when you have more than one bathroom.I would recommend that so long as you have the space to do so, you design the bath to have a tub/shower combo.