TOPSHAM — After a sketch plan review with the Planning Board on Tuesday, a proposed 47-unit housing development is expected to return for preliminary subdivision review early next year.

Developer Dan Catlin wants to build 47 single-family homes off of Mallett Drive. The Planning Board conducted a site inventory analysis of the property, reviewing both the site’s constraints and opportunities for development, according to Rod Melanson, the town’s assistant planner.

Catlin – whose developments in town include lots on Winner’s Circle and Topsham Fair Mall Road – is proposing an open-space development, and the Planning Board found that Topsham’s open space ordinance language does apply to that proposal, Melanson said. That stipulation requires a minimum of 30 percent of the property to be set aside for open space.

Wetlands are minimal on the site, and are primarily in open-space areas.

“What we call in our ordinance the primary conservation areas of the site – streams, wetlands, steep slopes – all of those things are being preserved on-site,” Melanson said, noting that any impact on wetlands would be minimal.

About 8 1/2 acres of the 26-acre property will be conserved in open space.

Doing an open-space project allows a developer greater flexibility in lot dimensions than is allowed under the town’s standard subdivision rules, Melanson said.

“The applicant is choosing to do single-family lots out there; they’re not doing condominiums, where they would be able to get more units,” Melanson said, noting that the lots proposed are about the same size as the ones on Mallett Drive.

The proposal will require both preliminary and final subdivision approval.

Alex Lear can be reached at 781-3661 ext. 113 or alear@theforecaster.net. Follow him on Twitter: @learics.