Sunday, September 21st was a busy day for New York City Mayor Bill de Blasio. He joined U.N. Secretary-General Ban Ki Moon and former U.S. Vice President Al Gore in a march through the streets of New York City with over 300,000 participants to draw attention to the issue of climate change in advance of the United Nations Climate Summit this week. That same day, he announced a sweeping plan to overhaul energy-efficiency standards for City buildings. The Mayor’s “One City, Built to Last” plan, available here, commits to an 80% reduction of greenhouse gas emissions by 2050 and the retrofitting of every city-owned building within ten years. HUD Secretary Julian Castro will dedicate a team within HUD to work with the New York City Housing Authority, the largest public housing owner in the country, on the initiative. Two NYC housing agencies will be involved in launching new initiatives aimed at increasing efficiency upgrades in affordable housing as well. The New York City Housing Development Corporation (HDC) and the New York City Department of Housing Preservation and Development (HPD) will begin requiring a “green” capital needs assessment (CNA) for all moderate rehabilitation projects financed by the City. Currently, substantial rehab and LIHTC projects must meet Enterprise Green Communities standards, but moderate rehab projects are not required to do the same. In addition, HPD will develop a green affordable housing loan program for small and mid-sized multifamily owners to undertake energy and water efficiency improvements using low-interest loan financing in exchange for agreeing to an affordable housing regulatory agreement with rent stabilization, income limitation and maximum rent provisions. According to the Mayor’s plan, the new green loan program may leverage existing financing sources such as NYSERDA or New York State Weatherization Assistance.