A geothermal retrofit for a 1912 lakeside estate
Replaced two aging boilers with a closed-loop geothermal system, cutting heating cost by 63%.
The challenge
The original scope came in as a straightforward replacement. Once we opened the mechanical rooms and pulled twelve months of BAS data, the picture shifted. What looked like an aging system was actually a design mismatch — the loads had drifted over two decades of tenant fit-outs, and the equipment was fighting the building.
The solution
A phased conversion. New equipment sized to the actual load, not the load stamped on the drawings. Controls rewritten. Sequences of operation rebuilt from scratch. The old system stayed live through six months of installation so tenants never lost service.
The result
First full winter: 41% reduction in energy cost against the prior year, normalized for weather. Peak demand down 32%. Zero occupant complaints for four straight months. And a client who is now on year three of a continuing maintenance contract.
What it cost
Flat-rate project pricing, quoted before work began.
- Vertical loop field — 6 bores at 320 ft
- $41,200
- Water-to-air heat pump + variable-speed air handler
- $28,600
- Distribution rework and zoning (4 zones)
- $14,900
- Controls, commissioning, and airflow balancing
- $7,100
- Permits, decommissioning, and site restoration
- $4,600
Before $21,300 in federal and state incentives — net $75,100.
Figures reflect this project's scope and conditions. Your building will price differently — get a scoped estimate.