Building officials from Gloucester and Poquoson set up a display at Lowe’s in Gloucester on April 17 to answer questions from contractors about protecting buildings in areas designated as flood zones.

One way to protect a building is to elevate it, said Ken Somerset, building official for Poquoson who previously was Gloucester’s building official. But more often, Somerset said contractors will install flood vents, a much easier and cheaper alternative that will allow water to pass through foundations and minimize damage to the structure.

Somerset and Paul Koll, the current Gloucester building official, demonstrated how a flood vent works. The units, made of plastic or metal, open to let water flow through; this is an alternative to having flood waters slam into a structure.

Contractors are familiar with construction standards, but many homeowners are not, Koll said. A homeowner living in a flood designated zone must have the vents installed in his or her building. Buildi...