In the 1980’s and 1990’s Moroccan – American cooperation pioneered the upgrading of unauthorized and informal housing in Moroccan cities. In Tetouan, local authorities, local businesses and the 11,000 households of the Dersa-Semsa community worked to assure roads, water, sewage and electricity. The project contributed to improving the living conditions of 90,000 residents and made the surrounding areas more economically vibrant. More importantly, this model of improving existing neighborhoods rather than tearing them down and rebuilding, was replicated in 30 Moroccan cities.