I wonder if even 10% of the people using the environmental argument have changed all of their indoor and outdoor lighting systems to LED, are recycling water, have changed their water heaters to tankless, have installed solar, and are using water and energy efficient items in their houses?

Having an open conversation about any possible contributing factors, including outdoor exposure, could help resolve the situation.

For example, we finish the basements with indoor/outdoor carpet (instead of LVP, which makes it feel a lot more homey), because we know parents go nuts in the winter if they can't send the kids downstairs to pay - or have a space for the guys to watch the game on Sunday.

MTR is less spend on furniture, less guests, and at that price point for a buy, will likely make more money and have less upkeep and management.

Even if the tenants are allergic, they can avoid that area for a short period of time, just like they would do in any outdoor space.

I would caution against a playroom as just like a pool or outdoor playground that brings a higher risk liability with it. 

Physician by trade in NC, but interests in prehospital medicine and the outdoors.   

Maybe leave a kayak for guest to use (have them sign waivers in case of accidents).Get some old furniture, some bicycles to loan and make a bed and breakfast!?

In that way, they appreciate everything being turnkey, with no need to buy linens, kitchen ware, and furniture nor set up utilities.

(optional)Kitchen Remodel (2020): Updated countertops, cabinets, and installed new stainless steel appliances.Bathroom Renovation (2019): Added new tiles, modern fixtures, and a glass shower enclosure in the master bathroom.Finished Basement (2018): Added 600 sq. ft. of finished space, including a family room and home office.New Roof (2021): Replaced the entire roof with new shingles and added improved insulation.Landscaping (2022): Redesigned front and backyard with new plants, sod, and an outdoor seating area.Energy-Efficient Windows (2020): Installed energy-saving windows throughout the home.