The California Supreme Court decided unanimously Monday that cities and counties may require developers to provide below-market-rate housing as a condition of a building permit...... Monday's decision stemmed from a constitutional challenge of an affordable housing ordinance passed in San Jose five years ago..... The law requires developers building 20 or more housing units to offer 15% at below-market rates or pay into a city fund. .........“The community as a whole should bear the burden of furthering this interest, not merely some segment of the community.”