The 1960s and 1970s saw a boom in residential housing developments across many parts of Europe. Today, many of those properties are in dire need of renovation, which often renders whole apartment blocks uninhabitable for a significant period of time, causing disruption for tenants and loss of income for owners. D. Carnegie & Co AB, a Stockholm-based property developer, has established a more efficient and profitable way of managing such projects and now owns over 18,000 properties around the Greater Stockholm area.