
A developer is laying the groundwork for what would be the tallest building in Maine history — a bold new addition to Portland’s skyline.
Here’s what we know so far about the proposal, its timeline and whether it’s likely to happen.
Q: What is the project?
A: The proposal at 45 Union St. is for a mixed-use, high-rise planned for the heart of the Old Port. If built as envisioned, the tower would rise 30 stories and stand about 350 to 380 feet tall.
The tower is part of a larger project known as Old Port Square, which would occupy an entire city block — bounded by Fore, Union and Middle streets — and would include residential units, commercial space and possibly a hotel component.
The Portland-based developer, East Brown Cow Management LLC, has already acquired the land and been through one round of review from city staff. The developer says its vision for the project includes pedestrian pathways, outdoor seating and newly planted trees.
On Sept. 23, the proposal came before the Portland Planning Board for an initial review. The developer will likely submit an updated proposal later this fall based on the feedback it received.
Q: Is this a sure thing?
A: Not at all — at least not yet. The proposal is still in its early stages and has not received formal approval from the city. In fact, the application is still under review, which means it hasn’t even entered the official permitting process.
The project will face a number of hurdles, including site plan review, compliance with zoning regulations and a public hearing, where local residents and stakeholders can voice concerns.
In short, the building is far from a done deal — it still needs to navigate a lengthy and complex public process.
Matt Grooms, the city’s deputy director of planning and urban development, said the proposal complies with zoning and land use laws. At this point, he says it’s likely that if all continues to go smoothly, the project will be approved by the planning board.
Q: So what are the next steps?
A: Once the developer submits an updated proposal, incorporating feedback from the planning board, city staff will review it again.
Then, the planning board will consider the project twice more. At an initial workshop session, the board will examine the building’s height, architectural compatibility, land use and environmental factors. In a second workshop, the board will focus solely on the project’s potential impact on traffic.
Once the city and planning board determine all is in order, the planning board will sign off on the project. There will be an opportunity for public comment at both planning board meetings.
It’s unclear when the planning board will revisit the proposal, but Grooms said it will likely be in the next three to six months.
“If the project is complying with zoning requirements and (the developers) are able to respond to both board and staff feedback, then the board is obligated to approve the project,” Grooms said.
If approved, the developer would still need to secure building permits, finalize financing and begin work on detailed construction documents. The timeline for those steps can vary widely.

Q: Why now?
A: Portland recently updated its zoning laws through a yearslong “ReCode” project. The project wrapped late last year, and with its completion came changes to laws about how tall buildings can be in some central neighborhoods, including the Old Port.
Previously, the maximum building height in the city was 220 feet. Now, it’s 380 feet.
Portland’s Plan 2030, the city’s comprehensive strategy for the coming years, laid out goals for the city’s future, including significant new housing development, climate resilience and easier access to public transportation. Those plans prompted the updates to the zoning laws.
With limited space on the peninsula, developers are increasingly looking to build up rather than out. East Brown Cow said in a written statement that it hopes the building will contribute positively to the city’s downtown.
“With the design of both the building and landscape intended to source local materials, evoke quintessentially Maine-based craftsmanship and design motifs, and achieve focused environmental goals, the project aims to contribute to Portland’s evolving urban landscape, both for current and future generations,” the developer wrote.
Grooms said the proposal aligns with the vision that the ReCode project was intended to foster.
“It would bring new residences downtown in an area that is walkable, connected to public transportation, and it provides that 24/7 vibrancy that the city called for downtown,” said Grooms.
He also noted that the developer’s application doesn’t propose any additional off-street parking, which aligns with the city’s sustainability goals.
“The city is actively working toward shifting away from automobile-centered development,” he said.
Q: How much could it cost?
A: The developer hasn’t publicly disclosed an estimated cost for the project, and it’s likely too early for a firm number anyway. However, for context, Portland’s current tallest building — an 18-story apartment building known as The Casco, completed in 2023 — had a price tag of around $64 million. The Union Street proposal is larger and more complex.
The final cost will depend heavily on factors such as material prices, design finishes, foundation complexity and construction timelines — all of which remain in flux at this stage.
Q: How long would construction take?
A: Once all approvals are secured and construction begins, the project could take three to four years to complete. That timeline would include excavation, foundation work, core structure and interior buildout.
But before any of that can happen, the developer must clear the regulatory process, finalize financing and prepare the site. Construction likely wouldn’t begin before late 2026 or 2027, pushing the tower’s potential opening to 2030 or later. Delays — whether from legal challenges, labor shortages or market conditions — could easily extend that timeline.
The Old Port Square proposal could signal a new chapter in Portland’s development story — but for now, it remains just that: a proposal. Whether it ultimately redefines the city’s skyline or fades into the background of unrealized plans remains to be seen.
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