Senior principals Leslie Kahn, P.E. and Ivan Pollak, P.E. have over half a century of combined experience. Leslie Kahn has been practicing since 1962 and Ivan Pollak since 1976. The Principals both teach environmental technologies at the renowned Parsons School of Architecture at New School University and are regularly invited to share their expertise at speaking engagements. Our staff comes from around the world, creating a diverse cultural environment full of wisdom gathered from four different continents and many different backgrounds.