I renovated the house to have energy efficient windows, doors, and energy source (solar panels).

They are energy efficient and help reduce the monthly heating bills.

They are energy efficient and help reduce the monthly heating bills.

Unfortunately, there is no silver bullet. 

Bottom line, you don’t know what you don’t know and there may be a silver bullet here that one of their previous neighbors already knows.

This rental property will be designed with a keen focus on generating a healthy cash flow.Project Blueprint:Budget: Allocated at $200,000, covering construction and all related expenses.Focus: To merge energy efficiency, durability, and tenant comfort with cost-effective construction strategies, making the rentals both affordable and sustainable.Location: Currently scouting – I'm open to suggestions and insights on ideal locations supporting this vision.Strategic Planning:Efficient Design & Planning: I'm considering compact, multi-functional layouts to optimize space usage and incorporate cost-saving construction methods without compromising quality.Sustainability & Efficiency: The plan includes investing in top-notch insulation, air sealing, energy-efficient systems, and sustainable materials to reduce the building's carbon footprint and operational costs.Budget Management & Cost-Saving Initiatives: Careful budgeting and exploring value engineering options are crucial, alongside seeking out grants or incentives for energy-efficient building projects.Community & Sustainability Goals: To create shared amenities to foster a community feel and implement systems encouraging tenants to monitor and reduce their energy consumption.Seeking Community Insights on:Cost-Effective Building Strategies: How can I ensure the project remains within budget while achieving high sustainability and efficiency standards?

Short Term Rentals take a lot of time and energy.

Hint: look for a solar architect, who acts as an adviser and works for you and audits the installer project proposal.Many states/utilities are no longer allowing net metering (kWh for kWh) and use instead all kinds of payback schemes (e.g. if you over-produce, they will gladly take your kWh for 3 cents and graciously allow you to take it back at night for 22cents - end result being, if your system is not properly sized, you will be producing energy for the utility and never recover the costs of the installation).

There's nothing wrong a slab foundation in fact they are more energy efficient typically. 

I do believe it's probably a question of 'when', not 'if', but at the moment, I don't see how that prototype saves any money, considering running wiring & plumbing with solid concrete walls (you'd likely furr over them with conventional stud framing, and would be building 2 walls instead of 1), meeting energy codes in different climates, envelope tightness, and satisfying aesthetic preferences.