Nevertheless, as the artist population grew, the city made some attempts to stem the movement, concerned about the occupation of space that did not meet residential building codes, and the possibility that the occupied space might be needed for the return of manufacturing to New York City. Pressured on many sides, and organizations such as the Artist Tenant Association and later the Soho Artist Association, the city abandoned attempts to keep the district as strictly industrial space, and in 1971, the Zoning Resolution was amended to permit Joint Live-Work Quarters for artists, and the M1-5a and M-5b districting was established to permit visual artists, certified as such by the Department of Cultural Affairs, to live where they worked. In 1987, non-artists residing in SoHo and NoHo were permitted to grandfather themselves, but that was the only extension to non-artists and was a one-time agreement.