Ed. Code, § 17042.5

(a) For purposes of determining the area of adequate school construction existing in an applicant school district pursuant to Section 17042.7, all portable classrooms, whether owned or leased, shall be included, except as otherwise provided in paragraphs (1) to (3), inclusive.

(1) Leased portable classrooms acquired by a school district shall not be included in the area of existing adequate school construction until January 1, 1991.

(2) Portable classrooms leased pursuant to Chapter 14 (commencing with Section 17085) shall be excluded from the area of adequate school construction. Portable classrooms obtained by an applicant district pursuant to subdivision (b) of Section 17088.5 also shall be excluded from the area of adequate school construction, except as to any portable classroom or classrooms for which the district rejected the board’s offer to purchase pursuant to that subdivision.

(3) Portable classrooms that have been leased or owned by the district for 20 years or more shall be excluded from the area of adequate school construction.

(4) Leased portable classrooms shall not be included in the area of adequate school construction for a period of five years from the date first leased by the district. That exclusion shall be extended by the board for one additional five-year period where the board finds that the continued use of the leased portable classrooms for classroom purposes is justified by additional growth in average daily attendance pursuant to the standards established by this part. If the board finds continued use to be no longer justified, it may extend the exclusion for a period of up to two years as necessary to maintain the eligibility of the applicant district for project funding pursuant to this chapter if the board finds that the district has made a good faith effort to obtain that funding in a timely manner. The additional five-year exclusion shall not apply to any portable classroom for which, under the lease agreement, the district is to take title, or the total consideration paid by the district for the lease and an option to purchase is determined by the board to be substantially equivalent to the cost of acquiring title.

(b) For purposes of this section, “portable classroom” means a classroom building of modular design and construction that meets all of the following criteria:

(1) Is designed and constructed to be relocatable and transportable over public streets.

(2) Is designed and constructed for relocation without the separation of the roof or floor from the building.

(3) When measured at the most exterior walls, has a floor area not in excess of 2,000 square feet.