HAMPTON, N.H. – When Ray and Marie Donner sold their inn in Camden, Maine, this spring, they invested the money in New Hampshire real estate to avoid capital gains taxes.

“We were going to get a substantial proceeds from the sale of the inn,” said Ray Donner, 49. “We kind of wanted to retire, but we’ve always made our money through real estate, not stocks.”

The Donners’ property swap, known as a “1031 exchange” for its tax code designation, helped them defer $300,000 in capital gains taxes.

The IRS allows people to defer capital gains taxes on real estate sales if they locate another property for reinvestment within 45 days and complete the purchase in six months. The deferment lasts as long as the money remains invested in real estate.

Such exchanges are becoming increasingly popular, said Robert Buckner, New England division manager for Asset Preservation Inc. in Nashua, which acts as an intermediary for land swaps.

Buckner says he has many Seacoast clients because property values in that part of the state are rising fast and small investors want to keep their gains.

“The use of 1031s seems to double every year in New England as more people are finding out about it,” Buckner told the Boston Sunday Globe. “Nobody wants to pay taxes if they legally don’t have to.”

The Donners sold their inn March 25. Attracted to New Hampshire because of its proximity to Boston and access to airports, they asked Kathy Walsh Real Estate Inc. of Portsmouth to help them find investment properties.

They found three within a month and closed the deals by the end of June. Altogether, they invested about $2 million in a Hampton office building, an office-restaurant-retail building in Durham and an Amherst office building.

“I didn’t want one large property. I wanted to diversify, just like in the stock market,” said Donner. “So I have 12 tenants total with the three buildings. I get rental income. It’s worked well.”

Donner knows that unless he and his wife pass their real estate on to their two children, they will have to pay the capital gains taxes someday.

“Eventually, if you want to retire and go to Tahiti or something, you do have to sell. So it’s kind of deferred,” Donner said. “But what it really works for is the economy. It keeps people investing their money without being penalized.”