The Biden Administration announced a multipronged approach to help developers convert unused office space into housing. First, it wants to tap into $35 billion in low-cost loans through the Transportation Department for projects near transit hubs. Also, it has a new guidebook to 20 different programs and technical assistance developers can access to help with complex and pricey conversions. Finally, it’s creating a list of federal buildings that might be ripe for a new life now that office vacancies nationwide are close to 25 percent and owners are defaulting on loans. However, the cost of financing is still spooking many developers.