Heat Pump Washer-Dryers: The $4/sqft Savings Most Developers Miss
All-in-one heat pump washer-dryers save $4/sqft on multifamily construction: no dryer ductwork, 2 HERS points gained, simplified electrical, lower fire risk.
On a recent multifamily project, we found $4 per square foot in construction cost savings from a single appliance change. The fix works on almost any multifamily development, and most developers have never considered it.
The change: all-in-one heat pump washer-dryers instead of traditional separate washer and dryer units.
Why This Saves Money
The savings come from four places, and they stack.
No dryer ductwork. Traditional dryers require dedicated exhaust ductwork from every unit to the building exterior. On a mid-rise building, that ductwork runs through walls, chases, and sometimes multiple floors. The material, labor, and coordination cost adds up fast. Heat pump washer-dryers are ventless. They condense moisture internally and drain through the same line as the washer. Zero ductwork required.
2 HERS points per unit. Heat pump combo dryers are significantly more efficient than conventional vented dryers (CEF of roughly 6.0 vs 3.94 for standard vented). That efficiency gain, combined with eliminating the dryer exhaust penetration, delivers approximately a 2-point HERS improvement per unit on our projects. Those 2 points create headroom that can allow you to downgrade something else in the envelope or mechanical system, compounding the savings.
Standard 120V outlet. Traditional electric dryers require a 240V dedicated circuit. The heat pump combo units we spec run on standard 120V. That means smaller wire gauge, simpler electrical panels, and fewer dedicated circuits per unit. The electrical cost savings are real, especially at scale.
Lower fire risk. Dryer lint in exhaust ducts is one of the leading causes of multifamily building fires. No ductwork means no lint accumulation means lower fire risk. Some insurance carriers recognize this with reduced premiums.
The Math
On a 100-unit building at 900 square feet per unit:
Dryer ductwork elimination: $1.50 to $2.50 per square foot saved, depending on building height and chase complexity.
Electrical simplification: $0.50 to $1.00 per square foot saved from 120V vs 240V circuits.
HERS score headroom: $0.50 to $1.00 per square foot in potential envelope or mechanical downgrades enabled by the 2-point improvement.
Total: approximately $3 to $4.50 per square foot. On a 90,000 square foot building, that is $270,000 to $405,000 in construction savings.
The Trade-Off
Heat pump combo units take longer per cycle than separate machines. A full wash-and-dry cycle runs 3 to 4 hours compared to about 2 hours for separate units. For market-rate apartments where tenants expect fast laundry, this may be a concern.
For affordable housing, workforce housing, and student housing, cycle time is rarely a deal-breaker. The cost savings matter more than the convenience premium.
The units also cost more per appliance than a basic washer plus dryer combo. But the installed cost (appliance plus electrical plus ductwork) is significantly lower, which is what matters for the development budget.