A heat pump installation can take anywhere from a single day to nearly a year—and that gap reveals something crucial about the hidden machinery of the clean energy transition. When Noah Gabriel and the New Buildings Institute began pulling data from TECH Clean California's database, they discovered that the timeline contractors report is far more complex than the hours spent wiring and mounting equipment on a building's exterior.
The challenge is that "installation" encompasses far more than the physical work. Permitting can stretch for weeks. Shipping delays from distributors who stock primarily gas heating systems can add months. Contractor workflow bottlenecks create additional lag. Yet concrete data on these offsite delays—particularly for commercial and multifamily buildings—remains sparse. What contractors submit is simply a start date and an end date, leaving the true drivers of lengthy installations largely invisible.
This data gap matters. As cities and states accelerate heat pump deployment to meet climate goals, developers and building owners need realistic timelines and cost projections. A project that takes three weeks tells a very different story than one that takes eleven months. Without granular understanding of where delays actually happen, the industry can't systematically reduce them or plan accordingly.
The New Buildings Institute recognized this blind spot and launched a survey to gather richer details. They're asking contractors, installers, and building operators who have worked with mini splits, heat pump rooftop units, window units, or VRF systems to report not just total time but the specific phases—permitting windows, supply chain waits, on-site labor—that comprise the full installation timeline. The goal is straightforward: move beyond the raw data to understand what actually drives variation in heat pump deployment speed.
"These data are a great starting point," Gabriel noted, acknowledging that TECH Clean California's database provides valuable evidence of the range. "What we don't know is how this field was defined." That methodological caution is exactly right. One contractor's "start date" might be the day they received the permit; another's might be the day they signed the contract. One "end date" might mark when the system powers on; another might be final inspection. Normalizing these definitions across the industry would help tremendously.
The implications reach beyond logistics. Heat pump adoption is central to decarbonizing buildings, which account for roughly one-third of global energy-related carbon emissions. If installations consistently stretch to four or six months due to permitting delays, that's not merely an inconvenience—it's a constraint on how quickly the transition can actually happen. Conversely, identifying bottlenecks creates opportunities for intervention. Streamlined permitting pathways, better coordination with suppliers, and clearer contractor scheduling could compress timelines significantly.
Gabriel and his colleagues plan to analyze survey results within weeks and share their findings publicly. For anyone in the heat pump industry—whether installing, specifying, permitting, or financing these systems—those insights will be invaluable. The clearer picture of what shapes installation timelines could become a roadmap for accelerating deployment at scale. In the race to decarbonize the built environment, understanding and eliminating delays isn't just efficient; it's essential.