A charge per square foot on residential and commercial construction within a school district. These fees, charged both to developers of new properties and to property owners who remodel, are based on the premise that new construction will lead to additional students. Individual school districts decide whether to levy the fees and at what rate up to the maximum allowed by law. The maximum, adjusted for inflation every two years, is higher for residential than for commercial construction. Districts are required to substantiate the financial impact of new development and show that they have used the revenues to address that impact. Proceeds may be used for building or renovating schools and for portable classrooms. Districts can tax a portion of their districts, often new housing developments, by establishing a Mello-Roos Community Facility District or a School Facility Improvement District (SFID).