A scarcity of buildable land is a reality in many parts of the United States. Nowhere is that fact more apparent than in cities along the Atlantic seaboard, where demand is strong and supply is constrained by the reality of the shoreline. In Portland, Maine, attractive neighborhoods near the city's busy "Old Port" downtown are already densely built out. But that isn't stopping developers and builders: They're making the most of the small infill lots that still remain. They're also tearing down existing older buildings to make room for modern multifamily apartment buildings and condominiums.

Near one busy corner in the peninsula neighborhood of Munjoy Hill, in the city's East End, JLC stopped in to see a four-family condo building under construction. The landowner lives in an existing house next door, but plans to move into one unit in the new four-unit building as soon as it's complete. Supervised by project manager Jeff Barker of Great Falls Construction (based in Gorham, Maine), specialty trades are making good progress. Designed by David Lloyd of Archetype Architects, the building will be small, but not simple: as a four-unit multifamily structure, it will need full fire separation walls and sprinkler systems. It will also have an elevator and a walkable rooftop terrace.

Infill Under Construction
Concrete contractors pour footings for a new four-unit building on an infill lot in Portland, Maine.

Elevators and firewalls, however, are typical in this kind of project. Around the corner is another project with an even tighter footprint: after extensively updating remodeling an older building, contractor Rob Paisley of Structural Integrity Contracting Services is putting up a new four-story structure on the same lot, shoulder to shoulder to the older two-unit building.

Standing on a stairwell landing of the new structure, at eye level with the older building's EPDM roof, Paisley said, "We're going up another 20 feet from here" — two full stories, plus (you guessed it) a walkable rooftop deck with ocean views. Like the Great Falls project, Paisley's building will have an elevator. And the required firewalls are substantial — a two-hour "burn wall" between the existing older building and the new structure, plus two-hour fire separations isolating the new building's stairwell and elevator shaft from the dwelling units.

Structural Integrity and Fire Safety
Contractor Robert Paisley explains the fire separation and structural details for a four-story condominium in Portland's East End.

"This will encompass every bit of residential and commercial building you can get in one building," says Paisley. "It’s overload if you’ve never done this before. There are 200 sheets of DensGlas Gold just in this section right here." The doubled-up gypsum board has to extend up both sides of the stairwell walls, explained Paisley: "There is no wood touching anywhere between the occupied units and the stairwells — which is a challenge like you can’t believe, to keep things tied together and straight while you’re building."

A few blocks away is an old building that's destined to be torn down. Local realtor Tom Landry is offering the house and lot together with a construction package, hoping for a customer who will pay for the property as well as demolition and construction of a new multifamily structure. Scattered around the neighborhood are similar investment opportunities: older single-family or multifamily structures waiting for the money to show up for a major renovation or replacement project.

Sites like these offer opportunity for investors and builders, and the new dense housing is creating space for new residents in a popular section of Portland. But the trend is a mixed bag for existing renters in the area, who can see themselves being priced out of the neighborhood. Affordable housing is a major concern in Portland, as in so many other East Coast cities. Partial relief for the problem in Portland's East End is coming in the form of a new energy-efficient affordable housing project designed by Kaplan Thompson Architects, and financed with the help of federal tax-credit money administered by the Maine State Housing Authority and the Portland Housing Authority.

Kaplan Thompson Architects: Bayside Anchor
Backed by federal tax-credit financing administered by the state of Maine, a prize-winning affordable Passive House apartment building is rising out of the ground in Portland's booming East End.

"This is the first affordable housing built by the City of Portland in about 30 years," architect Jesse Thompson told a seminar audience at the Northeast Sustainable Energy Association (NESEA) Building Energy conference in Boston in March. Kaplan Thompson got a big boost when they won a cash prize for the project from an international architecture competition. But the 42-unit project still had to survive two grueling rounds of plan reviews and cost cuts before the tax-credit funding came through. This month, however, construction is well underway: the concrete-block elevator tower structure is in place, and the slab pour is scheduled for this week. And despite some cutbacks in the building's insulated envelope and heating system, says Kaplan, the project is still on track for Passive House certification.

A mid-March snowstorm — no big surprise for Mainers — created a brief speed bump for Portland builders. But with weather forecasters predicting a warm spring, it's already looking like a busy year ahead.

A worker shovels snow from the insulated subgrade at a Great Falls infill project in Portland, Maine, after a sudden March snowfall.
A worker shovels snow from the insulated subgrade at a Great Falls infill project in Portland, Maine, after a sudden March snowfall.