On Thursday, December 19, the Senate reauthorized the 179D Energy Efficient Commercial Buildings Deduction through 2020 (and two years retroactively to include 2018 - 2019) as part of H.R. 1865, a year-end federal spending bill to fund the federal government. This keeps this important deduction available for commercial property owners through 2020, and allows them to claim it for 2018 and 2019 as well (the provision had previously lapsed at the end of 2017).
The 179D deduction allows commercial building owners who improve the building's energy-efficiency to receive a deduction of as much as $1.80/square foot in the year the upgrade goes into service, after receiving a proper third-party certification. It is available for both new construction and retrofits, and does not favor any particular method of conserving/reducing energy use. It encourages commercial building owners to make energy-efficient improvements, but importantly gives them the flexibility to make their own choices as to how to best accomplish that.
NAR is a member of several coalitions which advocate for 179D's long-term reauthorization, and will continue pushing that in 2020 ahead of its expiration.