(

a) The allowable building area of any project, as calculated under this article, may be increased by any applicant school district, where the increase is funded exclusively from sources other than any state programs administered by the State Allocation Board. Any increase in building area pursuant to this

section in a project for which construction commenced on or after January 1, 1987, not to exceed percent of the area that would be allowed under applicable state standards, shall be excluded from the calculation of the area of adequate school construction for the purposes of all subsequent project applications by the district under this chapter. (

b) The maximum building cost permitted for any project under this

article may be increased, by not more than percent, by any applicant school district, where the increase is funded by the district exclusively from the proceeds of a general obligation bond measure approved by the voters of the district or of a special tax pursuant to the formation of a community facilities district under

Chapter 2.5 (commencing with

Section 53311) of Part of Division of Title of the Government Code, or both. In order to qualify for this purpose, any tax or other charge authorized pursuant to that approval or formation, respectively, shall apply uniformly to all taxpayers or all real property within the school district, rather than to a particular class of property or taxpayers, and shall require that the amount of the school facilities fee or other requirement that may be levied by the school district pursuant to

Section 17620, in addition to that tax or other charge, not exceed the amount deemed by the governing board to be necessary for the interim school facilities needs of the district.