PropDev: turning one house into six homes
Personal project · 2026 · Design · Build · Financial modeling
A financial model and working calculator for replacing aging single-family homes with 6–10 smaller units, priced for buyers who can’t afford the house they replace.

The opportunity
Baby Boomers will pass on an estimated $70–90 trillion over the next decade, much of it in single-family homes. Heirs sell about 70% of inherited homes, often in neighborhoods the next generation can’t afford. The same lot can hold 6–10 units, each priced well below the old house but worth more together.
How the deal works
- Find aging owners on well-zoned lots
- Partner before the sale
- Raise project capital
- Rebuild at 6–10 units
- Sell below local home prices
Try the calculator
Model construction financing, a seller-financed note back to the homeowner, and traditional build vs. prefab, across the Property, Development, Summary and Ownership tabs.
Open full screenCosts, modeled bottom-up
At 6–10 units per lot, small per-unit cost swings compound fast, so pricing is built system by system rather than per square foot. Here is one system: all-electric heating and hot water for a 6-unit building, net of rebates and tax credits.
| System | Project total | Per-unit avg. |
|---|---|---|
| Ducted heat pump HVAC | $74,500 – $174,000 | ~$12,400 – $29,000 |
| Heat pump water heaters | $18,300 – $44,400 | ~$3,050 – $7,400 |
| Net after incentives | ~$86,000 – $201,000 | ~$14,300 – $33,500 |
The same approach covers structure, sitework and soft costs, so the per-unit price can be defended line by line to capital partners and to owners trusting the model with their land.