Maine PlaceCode Library: An Open-Source Toolkit for Small-Scale Development

Ivy Vann, an IncDev Faculty Member and small-scale developer based in New Hampshire, likes to joke that the same guy sold the same terrible zoning code out of the back of a Ford station wagon up and down the East Coast. Town after town adopted a set of land use rules that made most of their buildings functionally illegal.

While it’s not unreasonable for a community to want to have a say in how a building in the neighborhood looks and feels, it’s no secret that these moldy old zoning codes have deeply failed: driving up housing costs, rendering block after block of beloved historic structures “nonconforming”, and creating a huge obstacle for small-scale developers who might want to try their hand at building more of the traditional architecture that makes their place so special. 

Those old codes focused more on separating uses for buildings and replicating a suburban development pattern writ large—regardless of what was built on the ground. They were predicated, too, on a landmark Supreme Court decision that characterized a multifamily home next to a single-family home as a “pig in the parlor,” an essentially classist ruling that has deep implications to this day. 

Ivy estimates that these Euclidean zoning codes—named after the city where the court case took place—are the law in the vast majority of communities in the country. Ninety percent of cities and towns in America have outdated zoning that forbids copying off their old growth neighborhoods, downtowns, and main streets, and instead largely promote large lots, single-family homes, and suburban sprawl. And this has a consequence for affordability, too: “If you have to have a big house and a big lot, then it’s going to be expensive,” she says. 

In the last year, a group of collaborators outlined a solution: the Maine PlaceCode, an ambitious open-source zoning code designed to legalize historic neighborhoods and promote similar development. The PlaceCode is a simple, digital-first library of zoning that emphasizes form—the way a building looks and meets the street—over use restrictions and arcane metrics like floor-area-ratio.

The development of PlaceCode was led by the Principle Group over nearly a decade, with many code-users, innovators and supporters contributing time and talent. The release of the Maine PlaceCode Library came as a result of additional funding support by the Maine Department of Economic and Community Development, Housing Opportunity Program.

It starts with a lot of measuring. In a webinar walking through the PlaceCode, Ivy shared an example of crafting similar zoning in her town. There was a cluster of historic cottages a few towns over that they were interested in replicating. So Ivy studied them, measuring aspects like how tall they were and how close they were to the street, and wrote code that allowed them to be emulated. In the intervening years, a few townhome projects have been built in Peterborough, and, despite initial concerns, the new units are cherished and are rarely on the market. 

Ivy’s collaborator Ben, whose technical expertise has contributed to much of the PlaceCode Library, also wanted to promote development that called back to the historic New England architecture in his town. Ben lives in Newcastle, Maine, and just across the river is Damariscotta, which has a charming red-brick main street Newcastle wanted to emulate, but its code was getting in the way. 

Five years ago, Newcastle replaced all of its zoning with a new visual PlaceCode that streamlines and updates old Euclidean zoning.  This updated system makes it easy for residents and developers to understand what can be built where, and promotes traditional development styles, strengthening Newcastle’s Main Street. 

Newcastle’s Main Street lies within the Town Center District, which has updated design standards that specify massing and architectural elements like gables, dormers, canopies, and cupolas. These standards aim to make new buildings look and feel like the beloved older ones. It’s a huge step forward from an old code that had once made those buildings illegal. 

Because the PlaceCode is open source, Ivy and Ben encourage folks to remix it, taking pieces that work for their community, and to adjust as needed. Far from the stultifying effects of Euclidean zoning, the PlaceCode promotes consistency, clarity, flexibility, and efficiency—all aspects that serve, rather than hinder, the work of a small-scale developer. 

The PlaceCode was conceived as an open-source kit of parts. Not all of the pieces may be applicable to every community, but it’s relatively straightforward to pick and choose what you’d like to implement—whether it’s explicitly allowing for a certain type of building in your zoning code, or standards for streets and roads.

Ivy recommends starting with a strong planning and community engagement process, in which the community gets a chance to weigh in on the types of development and architectural features they’d like to see. This sets the stage for the city or town to adopt a tailored version of the PlaceCode. “Let’s figure out a place we like, and then measure it,” she says. 

In Newcastle, a consultant helped the Town to adopt a modified version of the PlaceCode. For municipalities in other areas, this might entail hiring a planning and zoning firm to measure the buildings and architectural styles that make your place distinct—using the PlaceCode as a template to promote Portland-style bungalows or the pueblo-style of the Southwest. It’s a foundation to enable folks to more easily build more of what already exists. “As the town grows,” Ivy says, “it will grow in the same pattern.”

For incremental developers looking to shape their place, it’s a far clearer way of understanding the feasibility of a project and being able to invest in their place—a far cry from some old code sold out of a station wagon. 

Learn more and Access the Maine PlaceCode Library:

• Maine PlaceCode Library

• Great Idea: Form-Based Codes | CNU

About the PlaceCode Library Creators: 

PlaceCode Library was created by a coalition of experienced form-based planners.

Ivy Vann is an IncDev Faculty Member and a planner and designer at Ivy Vann Town Planning and Urban Design. She works on projects in New England, including charrettes, planning projects, code review, master planning, and comprehensive planning. She also has experience serving in the NH House and on her town's planning board. Vann is certified as an AICP and CNU-A.

Ben Frey  is a Select Board Member and Planning Board Chair in Newcastle, Maine.

Written by: Noah Harper. Noah Harper, AICP, is a city planner focused on housing, transportation, and equitable development. He currently works at MassDOT as a regional transportation planner, and writes about urbanism on Substack at Power and Place.