Chris Wasileski, left, and Jonathan Leahy stand near a Topsham quarry around which part of the fourth phase of the Highland Green housing community is to be built. Wasileski is director of development with the Sea Coast Management Co., which is developing the parcel. Leahy is Highland Green’s director of marketing and sales. Alex Lear / The Forecaster

TOPSHAM — Sea Coast Management Co.’s proposal to add 48 cottages and an assisted living facility situated less than 50,000 square feet to its Highland Green development goes before the Planning Board on Tuesday, Sept. 17.

Evergreen Circle, which loops around conservation land, would be completed as part of the project. The cottages would be tucked in near Highland Green’s fifth and seventh golf holes, and run down along a quarry, according to Jonathan Leahy, the company’s director of marketing and sales.

This visual shows Highland Green’s planned six phases. The third is nearly complete, and the fourth, shown in orange, goes before the Topsham Planning Board Sept. 17 for site plan approval. Courtesy Highland Green

“It’s a long time coming,” Chris Wasileski, Sea Coast director of development and son of Highland Green and Highlands developer John Wasileski, said Sept. 4 in an interview alongside Leahy. “We’ve hit just about 200 homes through three phases of the overall development.”

The single-level cottages will be a base size of 1,600 square feet with a two-car garage and possibility of adding a 1,000-square-foot daylight basement and an 800-square-foot loft. Sunrooms and patios can be of various sizes, according to what the owner desires. The base cost to buy a cottage could be about $550,000.

The company’s strategy, similar to housing developments in Falmouth and Cumberland, “is to not build cookie-cutter homes,” Wasileski said. The developer wants to erect “homes that have character, homes that are very livable, homes that are sustainable.”

Solar panels on each home will produce the energy each structure consumes. Home maintenance services will also be offered.

“If you were to move into one of these homes, you would have all the comforts and technology of the home that you’re moving from,” Wasileski said, “but with all the amenities and service package that a 55-plus active-adult community offers.”

Along with the nine-hole golf course is a 230-acre nature preserve that runs along the Cathance River and includes a series of trails and the Cathance River Education Alliance’s ecology center.

The assisted living facility to the south of the cottages along Audubon Way will include 48 units. Half of those will offer standard assisted living, and the rest will provide memory care for those with Alzheimer’s disease and dementia.

“This would convert Highland Green into a full-service retirement community, from just the 55-plus community,” Wasileski said. “You’re offering more of a continuum care of services.”

Highland Green’s campus design is “approved from a master planning perspective” with the Maine Department of Environmental Protection, he said. “But because this is a multi-phased project, there’s a master plan approval for the entire campus, but every time we start a new phase, we have to go back in for a review.”

Ultimate final approval, on elements such as stormwater systems, comes from the state DEP and Army Corps of Engineers.

Construction of the 48 units could cost about $26 million, while the assisted care facility could be $12 million, according to Wasileski.

The project would mark the fourth phase of the housing community, geared toward people 55 and older. A portion of the fifth phase, approved by the board last March, would be constructed concurrently with the fourth.

The fifth phase, to be located on a new street connecting Mountain Road to Village Drive, has been delayed by rising construction costs.

“We’ve had to make some adjustments to make the project feasible,” Wasileski said.

The first part of phase 5 includes six 16-unit, four-story apartment buildings with garage parking, which could have a price point of about $500,000. The two-bedroom apartments would all be corner units.

Due to design modifications Sea Coast has made since the Planning Board’s approval of that phase last year — such as adding a fourth floor to increase the number of units from 12 to 16 — an amendment from that panel will be required.

A final sixth phase, off Route 196, is geared toward some manner of commercial development.

It’s an option for “someone who maybe doesn’t want a free-standing home; they might want to be in an apartment where they can get services if they’d like, or just live completely independently,” Leahy said.

The timeline for the phases depends on pre-sales, Wasileski said.

“Typically, we 50 percent pre-sale a neighborhood before we start infrastructure construction,” he said. “And we do not build a unit until it is spoken for.”

Ground could be broken next spring on the phase 4 and 5 units. Wasileski hopes to build 15-20 units per year, depending on market demand.

“We’re going to hit the market any day now,” Leahy said.