Boulder’s push toward electrified heating has made heat pump conversions one of the steadiest sources of HVAC work in the city, and a specific technical reality shapes what that work actually involves. A large share of Boulder’s older housing was built with radiator or boiler heat and simply never had ductwork installed. Converting that kind of home to a ducted heat pump system means adding an entire duct network to a house that wasn’t designed to accommodate one, not just swapping equipment.
Retrofitting ductwork into finished walls and ceilings is where installation mistakes get expensive. Running ducts through a house that was never built for them means cutting into finished spaces, working around structural elements that weren’t mapped for this purpose, and making judgment calls about routing that a new-construction install never requires. A poorly sealed duct run or a compromised structural element discovered after the fact turns a straightforward install into a completed operations claim.
Ductless mini-split systems avoid that problem, and bring a different one. Plenty of Boulder contractors steer older-home clients toward ductless systems specifically to sidestep the ductwork question, which shifts the installation risk toward refrigerant line routing through exterior walls and the electrical connection for each indoor unit. That’s less structural risk and more of the standard refrigerant handling exposure that comes with any heat pump work, still real, just a different category of mistake.
The building code conversation is a live one for this trade specifically. Boulder’s code requirements for new and substantially renovated construction touch mechanical systems directly, and contractors doing heat pump work need to stay current on what those requirements actually specify rather than working from what was standard five years ago. A system installed to outdated assumptions can create a compliance problem for the homeowner that traces back to the contractor’s work.
Refrigerant handling deserves the same attention here as anywhere else in this trade. Pollution liability coverage closes a gap that standard general liability policies typically exclude, and it’s relevant on every heat pump job regardless of whether the install is ducted or ductless.
None of this is a reason to avoid the work. Heat pump conversions are a real and growing part of the Boulder HVAC business, and contractors who understand the specific risk of retrofitting old construction, rather than treating every job like new-build installation, are the ones who avoid the expensive surprises. Worth a look at your own book, though. If ducted retrofits have quietly become half your jobs since the policy was last written, the policy is describing a business you no longer run.