“I took a day off for my retirement,’’ said Whiteman. “I went trout fishing, golfing and bicycling.’’

Among more than a dozen current projects, Coastal is building the Marriott Edition Hotel in Miami Beach; Mansions at Acqualina, a luxury condo in Sunny Isles Beach; Oceana, a condo going up at the site of the old Sonesta Beach Resort in Key Biscayne; and The Palace, a senior-living community in Coral Gables.

The company recently completed the St. Regis Resort & Residences, a Bal Harbour project that was stalled during the financial crisis but later revived; SLS Hotel in Miami Beach; Miami Carol City Senior High School, one of many projects for Miami-Dade County Public Schools; and the General Funding Office Building, headquarters for International Finance Bank in Miami.

Coastal’s work spans everything from Camillus House, a residential rehabilitation center for the homeless, to custom mansions on Fisher Island (where Murphy Jr. himself lives) to the University of Miami president’s Pinecrest home, which is named Ibis House after the school mascot.

Over the years, Murphy Jr. has built homes for celebrities such as Oprah Winfrey, Dolphins’ legend Dan Marino and Sylvester Stallone.

The company continues to broaden its reach. In 2011, Coastal joined with Winmar Construction to create a small projects division that handles commercial office interiors, hotel build-outs and smaller new construction jobs.

This year, Coastal formed a joint venture with Providence, R.I.-based Gilbane, a family-owned development and construction firm much larger than Coastal. Among other things, Gilbane has expertise in health-care and higher-education projects, including sophisticated “clean rooms,’’ technologically designed for research and manufacturing.

“We’re looking at 15 projects around South Florida,’’ Murphy Jr. said. “They bring the depth in the technical aspects. We have the local knowledge.’’

Things are buzzing for Murphy Jr. outside of work too.

His youngest son, Patrick “Erin’’ Murphy, 29, is the Democratic candidate for Congress seeking to unseat Congressman Allen West, a Republican representing Florida’s new 18th District, which covers Martin and St. Lucie counties and part of Palm Beach. Patrick Murphy, a certified public accountant who previously worked at Deloitte & Touche, is vice president of environmental services for Coastal.

His son’s bid prompted Murphy Jr. to curtail some of his own political activity: He stopped fundraising for Mitt Romney.

Murphy Jr.’s passion for building traces to his childhood when his father, also a skilled builder, brought him along to a construction trailer.

Growing up in Key West, Murphy Jr. started as a carpenter, driving an old Volkswagen van to small jobs like paneling a room or building a patio. He left the University of Miami without a degree to pursue construction and wound up building Seaboard Construction into the largest builder in the Keys.

Murphy sold Seaboard to Turner Construction in 1988 and started Coastal.

Between 1977 and 1993, Murphy’s firms built most of the public areas in Key Largo’s exclusive Ocean Reef Club and many of the homes.

After Hurricane Andrew in 1992, Coastal grew exponentially amid the rebuilding boom.