Though steel has become somewhat synonymous with the modern, high-rise office building, concrete is making a comeback in a big way.

55 Hudson Yards may be the most high-profile office building under construction in New York City to use concrete, but plenty of other buildings — like 512 West 22nd St., 40 10th Ave. and 61 Ninth Ave. — have gone with concrete for their construction, Crain's New York reports.

Several factors are driving the trend, most notably cost. Labor cost is lower for concrete than steel workers, and it is easier to adjust after initial plans have been made — like an additional balcony requested by Silver Lake at 55 Hudson Yards, which would have been prohibitively expensive to add if the building was steel.

Advancements in technology have also allowed concrete to support more weight, which office buildings tend to require over multifamily, and the lack of internal girders that come with steel mean higher ceilings and more potential for exposed materials, both of which are highly sought-after features among office tenants.