But my solution in your case would be to frame out a dividing wall of 2x4s and either drywall or if the basement is prone to taking on water then I’d look for something waterproof as opposed to the drywall.

Is replacing the HVAC with a completely different unit the best solution?

I feel this gives me the flexibility to find the right solution for my client and not just sell what my bank offers.

It took new construction costs from $800-2500 down to $325 / SF and instead of 2 years it can be done in 8-12 months (design, permits, fabrication, shipping, and erection) depending on how much homeowners customized the standard plans. 

I will assume positive intent here that this is not the experience you intend for your customers.

My company provides an all-in-one solution for clients.

Whether we’re flipping a house, helping a client find their perfect home, or designing a custom renovation, everything we do adds value—and that’s the ultimate goal.

We give an A-Z Solution.

Their customer relations person quit and you can NEVER talk to someone in person.  

@Kash Tacke I'm a big fan of ADU's in general especially here in the mid west, yes you could potentially be on the front of the wave, but housing density is the solution to the affordability issue, anytime you are investing with affordability in mind is a great strategy to me, and sound like there are some incentives or at least supporting winds form the local city, that in itself seems like it would be worth at least approaching an architect or contractor to bid up some plans or concepts to take tot he city.