The idea for The Vacation Project was born over multiple cocktail in a New York City bar. While animatedly swapping stories from their travels, three friends — Lindsay Bradley, 29, Mitchell Roy, 29, and Charlotte Bergin, 28 — realized that they all shared an interest in doing some volunteering in the destinations they visited. But they didn’t necessarily want to devote their entire getaways to service.

The tools to achieve these ideal vacations, however, didn’t seem to exist. “Most of the volunteering trips out there either required a multiweek time commitment or were way too expensive,” Ms. Bradley said.

And just like that, the Vacation Project, which would solve both issues, began.

Their travel company sells weeklong, small group trips to Costa Rica, Morocco and Nicaragua. The journeys are part leisure, part service: itineraries include between two and three days of charity work, in collaboration with a local nonprofit; for the rest of the time, travelers go on sightseeing tours, enjoy group meals at popular local restaurants and have downtime to explore on their own.

“Our trips are first and foremost a vacation, but they also make room for giving back,” Ms. Bradley said.

Combining short volunteering stints with leisure travel was once an anomaly but is becoming more common, according to Courtney Regan, the founder of the San Francisco travel company Courtney Regan Travel and an expert on what is known as voluntourism.

“Most people don’t have the time to dedicate two weeks to volunteering, and even if they did, traditional voluntourism trips can be pricey and physically arduous,” she said. “Now, there’s a burgeoning market for travelers who want to get a flavor of giving back.” 

At a cost of between $1,400 and $2,000 for accommodations, most meals, local transportation, tours, activities and the volunteering, The Vacation Project is also at an appealing price point for the 20- and 30-somethings the trio are targeting.

Ms. Bergin said that they chose the three countries because they are “on the radar” for travelers today but the company wants to show a side of them that is different from what most tourists see.

On the company’s inaugural trip this September, for example, which was to Costa Rica, the welcome dinner, in the capital city of San Jose, was a seven-course feast prepared by the Costa Rican chef Luis Protti in a 1940 Victorian home. While enjoying dishes like sausages with meat from nearby farms and gazpacho made from locally grown tomatoes, the group of eight watched a local band perform Latin fusion tunes.

A day of surfing and swimming at Uvita Beach followed, and then it was time to volunteer: the group headed to the Osa Peninsula, on the southern end of Costa Rica’s Pacific Coast, to help Osa Conservation, a nonprofit dedicated to protecting the peninsula’s biodiversity.

Over the next three days, they helped the charity’s staff — cleaning up plastic from the beach, replanting trees and tagging sea turtles.

With their charity commitment completed, it was back to vacationing. At Manuel Antonio Beach, on the central Pacific coast, the group enjoyed walks and ziplining in the surrounding rain forest, and after a final night in San José, they headed home.

The upcoming trips to Morocco, in January, and Nicaragua, in February, will strike a similar balance of service and play, but each has a different charity component. In Morocco, travelers will help Berber communities in the Atlas Mountains build irrigation systems; in Nicaragua, they will assist a school near the city of Granada with a new basketball court and general repairs.

Another company with a similar mission is Give a Day Global, a nonprofit that connects travelers with daylong volunteering opportunities in 15 countries; most cost $100, said the founder, Kerry Rogers. In Cancun, for instance, vacationers can help out at an after-school program for low-income children with tasks like cleaning and serving food.

“The majority of the people who sign up for these gigs are on one-week getaways and want to spend a small part of their trips helping the communities they’re visiting,” Ms. Rogers said.

Some hotels are also introducing programs where guests can volunteer for a half- or full day with local causes. At Grace Bay Club, on Providenciales Island in Turks and Caicos, guests have the option of spending an afternoon at a youth center near the resort teaching children how to read. Also, in the aftermath of Hurricane Irma, they can help build new roofs for the many schools on the island which were badly damaged by the storm.

These volunteering opportunities are free, and the hotel arranges transportation to and from the jobs, said Nikheel Advani, the resort’s co-founder.

As for the trio behind the Vacation Project, they’re happy that they’ve created a venture that fulfills their own wishes. “The idea of giving back and having a vacation all in one trip is something we really wanted,” Ms. Bradley said. “Our hope is that others do, too.”