New York City’s Department of Housing Preservation and Development has picked five design teams as the winners of a contest that sought creative ideas for building housing on smaller city-owned lots.

The winning selections for the Big Ideas for Small Lots NYC contest range from two- to seven-unit buildings that maximize limited space.

The city identified 23 lots around the city that are irregular or infill—from a 663-square-foot rectangular piece of land in the Bronx to a 1,800 square-foot triangular lot in Brooklyn.

The winning teams are: Anawan/101 + Kane AUD; Michael Sorkin Studio; OBJ; Only If Architecture PLLC; and Palette Architecture.

Building affordable housing on small lots is challenging in many ways, said Deputy Mayor Vicki Been, who described them as a “pain in the neck” because of feasibility and high cost.