To this point, the latest McGraw-Hill Construction report on new and remodeled green homes found that energy-efficient appliances are some of the first things homebuyers look for in a new house — second only to having enough square footage to live comfortably. This was true for both millennials and baby boomers — two generations poised to purchase homes in great numbers.

Why do homebuyers look for energy-efficient appliances? To save on monthly costs and anything related to maintenance. It’s common knowledge that HVAC systems account for a significant portion of monthly energy costs, so many homebuyers think of these systems first. In the latest study by the National Association of Realtors , homebuyers were asked to rank which features are most important to them in their new house. Respondents said HVAC systems were the number one essential feature when it comes to environment.

It’s no surprise the appetite for energy-efficient appliances and the concern over HVAC energy costs has resulted in strong and ever-increasing consumer demand for energy-efficient HVAC. Countless studies and surveys are concluding this very same thing — some looking at demand, others at supply. One example is Navigant Research’s recent report showing that annual revenue from energy-efficient HVAC systems will almost double in the next 15 years, growing to $33.2 billion by 2020.

For builders, the focus on energy-efficient appliances — and energy-efficient HVAC in particular — is an incredible opportunity. If homebuyers are looking for appliances from trusted, well-known brands, builders can feature these products. If buyers are searching out green-certified homes, builders can embark on green projects. This seems to be a time of “if you build it, they will come.” And, even more so, “if you build it energy-efficient, they will buy.”