(b)

1. (1) No city, county, or city and county shall, by administrative, quasi-judicial, legislative, or other action, reduce, or require or permit the reduction of, the residential density for any parcel identified to meet its current share of the regional housing need or any unaccommodated portion of the regional housing need from the prior planning period to, or allow development of any parcel at, a lower residential density, as defined in paragraphs (1) and (2) of subdivision (g), unless the city, county, or city and county makes written findings supported by substantial evidence of both of the following:

   1. (A) The reduction is consistent with the adopted general plan, including the housing element.
   2. (B) The remaining sites identified in the housing element are adequate to meet the requirements of Section 65583.2 and to accommodate the jurisdiction’s share of the regional housing need pursuant to Section 65584. The finding shall include a quantification of the remaining unmet need for the jurisdiction’s share of the regional housing need at each income level and the remaining capacity of sites identified in the housing element to accommodate that need by income level.
2. (2) If a city, county, or city and county, by administrative, quasi-judicial, legislative, or other action, allows development of any parcel with fewer units by income category than identified in the jurisdiction’s housing element for that parcel, the city, county, or city and county shall make a written finding supported by substantial evidence as to whether or not remaining sites identified in the housing element are adequate to meet the requirements of Section 65583.2 and to accommodate the jurisdiction’s share of the regional housing need pursuant to Section 65584. The finding shall include a quantification of the remaining unmet need for the jurisdiction’s share of the regional housing need at each income level and the remaining capacity of sites identified in the housing element to accommodate that need by income level.

(c)

1. (1) If a reduction in residential density for any parcel would result in the remaining sites in the housing element not being adequate to meet the requirements of Section 65583.2 and to accommodate the jurisdiction’s share of the regional housing need pursuant to Section 65584, the jurisdiction may reduce the density on that parcel if it identifies sufficient additional, adequate, and available sites with an equal or greater residential density in the jurisdiction so that there is no net loss of residential unit capacity.
2. (2) If the approval of a development project results in fewer units by income category than identified in the jurisdiction’s housing element for that parcel and the jurisdiction does not find that the remaining sites in the housing element are adequate to accommodate the jurisdiction’s share of the regional housing need by income level, the jurisdiction shall within 180 days identify and make available additional adequate sites to accommodate the jurisdiction’s share of the regional housing need by income level. Nothing in this section shall authorize a city, county, or city and county to disapprove a housing development project on the basis that approval of the housing project would require compliance with this paragraph.

(g)

1. (1) If the local jurisdiction has adopted a housing element for the current planning period that is in substantial compliance with Article 10.6 (commencing with Section 65580) of Chapter 3, for purposes of this section, “lower residential density” means the following:

   1. (A) For sites on which the zoning designation permits residential use and that are identified in the local jurisdiction’s housing element inventory described in paragraph (3) of subdivision (a) of Section 65583, fewer units on the site than were projected by the jurisdiction to be accommodated on the site pursuant to subdivision (c) of Section 65583.2.
   2. (B) For sites that have been or will be rezoned pursuant to the local jurisdiction’s housing element program described in paragraph (1) of subdivision (c) of Section 65583, fewer units for the site than were projected to be developed on the site in the housing element program.

2. (2)

   1. (A) If the local jurisdiction has not adopted a housing element for the current planning period within 90 days of the deadline established by Section 65588 or the adopted housing element is not in substantial compliance with Article 10.6 (commencing with Section 65580) of Chapter 3 within 180 days of the deadline established by Section 65588, “lower residential density” means any of the following:

      1. (i) For residentially zoned sites, a density that is lower than 80 percent of the maximum allowable residential density for that parcel or 80 percent of the maximum density required by paragraph (3) of subdivision (c) of Section 65583.2, whichever is greater.
      2. (ii) For sites on which residential and nonresidential uses are permitted, a use that would result in the development of fewer than 80 percent of the number of residential units that would be allowed under the maximum residential density for the site parcel or 80 percent of the maximum density required by paragraph (3) of subdivision (c) of Section 65583.2, whichever is greater.
   2. (B) If the council of governments fails to complete a final housing need allocation pursuant to the deadlines established by Section 65584.05, then for purposes of this paragraph, the deadline pursuant to Section 65588 shall be extended by a time period equal to the number of days of delay incurred by the council of governments in completing the final housing need allocation.