New York Mayor Bill de Blasio is set to explain how he will achieve one of his most ambitious goals: building or preserving 200,000 affordable homes over the next 10 years.

The Democrat campaigned last year on helping middle-class and poor New Yorkers, and housing costs have crystallized the squeeze they face.

New York University’s Furman Center for Real Estate and Urban Policy says the city’s median rent rose 11 percent from 2005 to 2012, to $1,216, while renters’ median household income rose about 2 percent, to about $41,000.

De Blasio has vowed to pursue mandatory inclusionary zoning, or requiring developers to include affordable units if they want permission for bigger buildings or other breaks.

Other possibilities include legalizing some illegal basement apartments.

De Blasio lays out his plans Monday.

(AP)