Some of the best design is born out of constraints. So when architects Sara L’Espérance and Michael Putman of Nova Scotia−based studio SUPRBLK were tasked with conceiving a new structure to accompany a summer residence in Biddeford Pool, they used the tight site as a catalyst for thinking outside the box. The clients, Kate Binzen and her husband Peter Lindsay, needed more space and also wanted to address their desire for outdoor living. The original three-bedroom home has been in Lindsay’s family for generations, and it was becoming cramped for the couple and their grown children. Building codes wouldn’t allow for an addition to the structure, which isn’t winterized, and the couple was craving a place they could enjoy year-round. “The main house is very small, with one bathroom, so we wanted to create a sort of apartment for the two of us,” explains Binzen. “This way, when the whole family is here, our kids can have the main house, and we can go next door.” As this property has been passed down through Lindsay’s family, it was only fitting that someone close to the family take on the new annex. “The clients are old family friends, and I actually used to babysit their kids,” says L’Espérance. “It felt like a full-circle moment.”

The architects turned their attention to a 130-year-old small, dilapidated carriage house adjacent to the residence. It was beyond repair and needed to be torn down, according to Putman, providing a clean slate to conceive something new. Due to setback requirements, they chose to reuse the carriage house’s existing footprint, so space was quite limited. “We have a lot of experience working with existing narratives and small spaces because we worked in England for a decade before starting our firm,” explains Putman. “The carriage house definitely inspired our design. We reused elements of the building, including the original barn doors.” Although a bit taller than the original structure, the new building has a similar side elevation thanks to a simple gable roof. “The clients were fond of the carriage house, so we took our cues from that,” says L’Espérance. “We stayed within the existing New England coastal vernacular, but the lines are more contemporary. We punctured the shingled shell with a dormer sheathed in horizontal timber siding. The same siding is revealed when the barn doors are open.” Meanwhile, a series of windows on one end faces the ocean. Between the two structures is a deck connecting the old and new, providing much-needed outdoor space. A screened porch was also added to the main house and features a roof deck that takes advantage of ocean views over the neighboring properties. “The porch has completely changed our experience of the property,” says Lindsay. The Georgia-based couple has an affinity for brick, so a terrace provides yet another spot for outdoor entertaining. (The bricks—a savvy Craigslist find by Binzen—came from a century-old schoolhouse that had been torn down nearby.)

Clocking in at just 884 square feet, the modest structure features an efficient floor plan that contains a bedroom, a bathroom, living and dining areas, a kitchenette, and a workspace. An inverted program, with the bedroom on the ground floor, allows for ocean views from the main living areas on the upper level. “The interior surprises and delights, with great light and views,” says Putman. “The main house has small openings and never took advantage of the sea views,” adds L’Espérance. “The vistas are really only accessible from the second story, so the clients are now able to discover a view that they never enjoyed before.”

Nods to the former structure include exposed timbers and natural wood accents that lend warmth. “We took the carriage house language and played with it a bit,” says Putman. Even the building method is rooted in tradition. “The structure uses balloon frame construction, where the upper floor integrates into the middle of a tall wall rather than erecting two separate walls with a floor in between,” he continues. “Most barns are built this way.” The architects put a contemporary spin on it, however: the floor of the upper level doesn’t span the entire width of the house, but instead looks down to the floor below.

To capitalize on space while maintaining the lofty, airy quality of the residence, the architects devised a smart solution to accommodate a workspace that doubles as an additional sleeping area. A staircase resembling a ship’s ladder leads from the upper level to a 100-square-foot “pod” that hovers above the living area. “In the office pod, the desk can be folded down to make room for a double mattress, and there’s a built-in bench on the opposite side that can be used for sleeping as well,” notes Putman. “Each piece is critical in a small area, so things need to be multifunctional. And from inside the pod, you can look over the balustrade and engage with the people below. It gives the sense of a larger, more meaningful space.” This unique architectural element was installed with “the least amount of material possible,” says builder Tim Spang of Spang Builders in Kennebunkport. “The floor system is suspended using metal rods with turnbuckles that come down from structural beams in the roof.” According to L’Espérance, “having tight constraints provides nice challenges and opportunities. We could have installed full floors, but this footprint allows us to play with light in a special way.” Throughout, dimmable pendant lights hang from the ceiling and cast a soft glow. “They almost look like floating candles,” continues the architect. “It’s a nice way to highlight the loftiness while creating a feeling of intimacy.”

Just as the clients gave the architects carte blanche on the overall concept, they let them take the lead on finishing the interiors as well. The palette was kept mostly neutral to “emphasize the sky, water, and landscape rather than compete with it,” says Putman. One exception is the bathroom, which is enveloped in a vibrant wallpaper. “The main house has wallpaper in each room, and the homeowners love some of those traditional New England elements,” notes L’Espérance. Indeed, says Binzen, “the wallpaper is a nice nod to the main house. We created a sort of modern mirror of it.” That’s not the only reference to the past in the bathroom, though: a porcelain toilet with a pull chain was salvaged from the carriage house and lovingly restored by a friend of the family. “With every project, it’s always fun to discover things on-site,” says L’Espérance. “We spent a day going through the carriage house with the clients, pulling out old tools, artwork, and other objects to save. The decor is a mix of old pieces, antiques, and contemporary furniture.” Other family heirlooms include hooked rugs, artwork created by both Binzen’s mother and Lindsay’s parents, and furniture the couple has refinished. “I love to leave room for those things within a design,” says L’Espérance. “It’s nice to allow for playfulness and some magical moments so that it’s not just us coming in with all new products. We wanted to be sure that the clients were a part of this project and that the finished space feels like them.”