Stephen Tilly is principal of a planning, preservation, landscape and architectural firm in Dobbs Ferry NY and has degrees in English Literature and Architecture. Since the 2nd National Passive Solar Conference in 1977 he has conferenced across the sometimes contentious boundaries between the preservation and the green worlds; he sees them as part of the same mission: conserving resources. The firm has won numerous awards including a Northeast Sustainable Energy Association (NESEA) award for the conversion of an historic greenhouse factory into low income housing over the Irvington Public Library. His firm continues to recycle our largest objects (buildings) and when absolutely necessary design very stingy new ones.