It's no secret that energy-efficient upgrades can reduce utility bills, so Indianapolis is giving that option to people who struggle to pay their bills. The Indianapolis Housing Agency recently took a bulldozer to some of its public-housing developments and replaced them with 29 sustainable apartments and townhomes, according to the Indianapolis Star. The new living spaces have energy-efficient appliances and heating and air conditioning systems, as well as one of the largest residential "green" roofs in the city. The roof atop the complex's garage has a stormwater runoff system, along with areas for residents to walk, sit and garden. The agency plans to build roughly 130 more units, at a projected cost of $34 million. Cities like Boston, Philadelphia and Denver are also leading the way in greening public housing.