BEDFORD — New housing does not necessarily lead to an increase in school enrollment that has traditionally caused hesitation among town planners, thanks to state households producing fewer children than in previous decades, according to a study released by the New Hampshire Housing Finance Authority (NHHFA).

“One of the issues that has always come up is what is the potential impact on communities in terms of school cost of new housing development,” said Dean Christon, who heads the NHHFA.

The study, which was done by Applied Economic Research of Laconia, takes aim at conventional wisdom about development and enrollment.

Researchers concluded that age-restrictive housing is generally encouraged in the state while new family housing is discouraged because of the concerns.

Christon said that since most education funds come from property taxes, officials can be hesitant to approve new development, fearing it will ultimately increase the tax burden.

“If you’re a public official and you think that a project is going to have a bigger economic impact on your community than it really is, you’re going to be less likely to be supportive of it than if you have better data,” Christon said.

Bedford Planning Director Rick Sawyer said residents often think more housing equals more enrollment. But he said the study’s findings are consistent with housing/enrollment ratios in the town. The study suggests a single-family home with three bedrooms will result in 0.64 school-age kids, and a typical two-bedroom apartment will add 0.17. Heritage on the Merrimack, a Bedford housing development built 10 years ago with 240 units, generated just 38 school kids.

Sawyer said studies like this are critical to the decision-making process and are cited in the proposal of new developments. “It’s important research that does need to be updated routinely, and we certainly do make use of it.”

A similar study was conducted by the NHHFA in 2005, with similar results. Christon said the current study was commissioned to determine whether the recession affected the numbers.

The study reports the state experienced rapid population growth in the 1990s, an increase of 11 percent, with an even higher increase in student enrollments as 39,000 new students entered the state, a 24 percent increase.

As opposed to new construction, this was due to the “Baby Boom echo,” caused by children of Baby Boomers entering the schools.

The 2000s showed higher student enrollment but less population growth. While the population increased by 80,714, school enrollment dropped by 21,600, despite an additional 44,300 housing units.

Of the state’s 161 school districts, only 31 added students in the 2000s.

The key factor in how many students are added comes down to the number of bedrooms per structure, both in the 2005 study and the current one. Single-family homes are four times as likely to house school-age children than condominiums.

“There really is nowhere near the number of school children generated per housing unit that people think,” Christon said. “And that’s really a product of changing demographics across the country.”

That means fewer people are having children — and that’s the case in most of the country, Christon said.

Data from the Department of Education and the 2010 Census were used in the study, in addition to case studies in Belmont, Milford, Rochester and Windham.

Christon acknowledged that regardless of the findings, the housing climate remains stagnant. “But we are hopeful that that market will begin to improve, and as it does you will begin to see market areas where developers are going to want to build new housing.”

Based in Bedford, the NHHFA, a public benefit corporation funded largely through federal grants, operates various programs to assist the housing of low and moderate income people. It has been influential in creating more than 14,000 multifamily housing units in the state.

“We hope (the study) make it easier for good development to move forward,” Christon said. “What we’re trying to do is make it easier for well thought out housing proposals that meet market needs to be able to get the approval they need.”

The study can be found at nhhfa.org.

srios@newstote.com