The success of Lisbon in attracting investment, companies, talent, and tourists in recent years has led to a huge increase in real estate prices which made it difficult for middle class Portuguese and foreigners, to buy or rent a house in Lisbon. In 2019, experts from PwC and ULI declare Lisbon the best city in Europe for investment and real estate development (Emerging Trends in Real Estate 2019). That means the demand for real estate (and prices) will increase even more.    To respond to this challenge we have developed a new model of real estate development Própria | Co-Investment inspired by the cooperative model, through which we can provide quality apartments at cost.