The office space for eight out of 11 major law firms that signed leases for new D.C. offices between 2011 and 2014 have yet to be filled by replacement tenants, according to data from commercial real estate firm Cushman & Wakefield. Law firms are the second-largest tenant in Washington after the federal government, and the legal industry's push to downsize in real estate to save money is leaving a gap in the local real estate market.