This bill amends local building ordinances by requiring municipalities to exclude below-grade areas from the calculation of floor-area-ratios (FAR) for new construction projects. The bill defines "floor-area-ratio (FAR)" as the ratio of a building's total floor area to the size of the parcel of land, and "below-grade area" as any part of a building that is entirely or partially below ground level, including basements and cellars. The legislation allows developers to utilize these below-grade areas for specific purposes such as parking, storage, and mechanical spaces without affecting the FAR calculation.

Additionally, the bill includes a contingency clause stating that if another bill (HB 631) from the 2025 legislative session becomes law, the newly inserted sections regarding FAR calculations will be renumbered accordingly. The act is set to take effect 60 days after its passage, with an effective date of September 30, 2025.