Owners stepped up their regional activity, launching billions of dollars of major projects in Delaware, Maryland, Pennsylvania, Virginia, West Virginia and the District of Columbia. Last year, the 20 Top Starts in the mid-Atlantic area tallied a total value of $10.7 billion, up from $8.44 billion in 2013.

Last year saw a significant increase in private developer work in major metro areas. For example, Hoffman-Madison Waterfront, led by developer Monty Hoffman, kicked off the $775-million first phase of its mixed-use development The Wharf in March 2014. Located along Washington, D.C.'s southwest waterfront, the project ultimately could include $2 billion in residential and commercial space.

The Trump Organization is undertaking a $200-million project at the Old Post Office in Washington, converting it into a Trump International Hotel. Lend Lease began work on the project, designed by Beyer Blinder Belle, in July.

Across the Potomac in Arlington, Va., JBG Cos. broke ground last year on the $146-million Central Place residential tower and the CEB Tower at Central Place, which will be an office building. Clark Construction Group is building both projects.

Private developers also generated a lot of activity in Philadelphia in 2014. Liberty Property Trust is again headed to the top of the city skyline, this time with its $1.2-billion Comcast Innovation & Technology Center. LF Driscoll broke ground in July on the Foster + Partners-designed project. Completion is expected in 2018.

Many of the tower cranes in Center City Philadelphia are perched over new residential towers. In November, Brandywine Realty Trust broke ground on its $131.6-million 1919 Market Street luxury apartment project. Dalian Development is building its $130-million Rodin Square Apartments project, and Property Reserve Inc. started its $120-million 1601 Vine Street project in September.

The team of BLT Architects and INTECH Construction began work last year on residential towers at 3601 Market Street for Southern Land Co. and at 3737 Chestnut Street for Radnor Property Group.