Bozeman’s Draft Development Code is Less Scary Than It Seems

Bozeman’s new draft development code uses a form-based approach to residential zoning. According to the Form-Based Codes Institute,

A form-based code is a land development regulation that fosters predictable built results and a high-quality public realm by using physical form (rather than separation of uses) as the organizing principle for the code.

The purpose of a form-based code is to provide a clear and predictable picture about how a neighborhood or area will look and feel for the foreseeable future by regulating the mass and scale of new developments. 

Rather than describing how a structure may be used, the new development code would focus on how a structure fits into the fabric of a neighborhood. Areas designated for residential use will still be areas designated for residential use. The essence of the Residential A district is that new construction must have, generally, speaking, the size and shape of a house. If you look closely in the historic neighborhoods north and south of downtown, you can find many, many examples of buildings that don’t stick out in any way but are actually contain five or more units.

A screenshot of a computer

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Five-unit building on East Story Street

For example, the building above on Story Street looks like a house but is a five-plex. This five plex could not legally be created under current code but could under the new code (provided it was able to meet the additional parking requirements). The image below shows eight units, seamlessly tucked into the neighborhood on South Black Avenue.

Eight-unit building on South Black Avenue

Some have fixated on the maximum entitlement of eight units per building, but that’s not how the new code works. The new code says, “within a building envelope that has roughly the size and scale of a house, and that sits on a lot with a yard and sits back from the street a similar distance as other houses, residential housing may be built.” That could be one unit, or that could be a structure divided into multiple units, so long as the form fits the neighborhood. The maximum of eight units is almost theoretical, since the other constraints (height, lot coverage, parking requirements, etc.) would almost always be the actual constraining factors.

The “new” dimensional limits are, in fact, quite similar to existing dimensional limits. I expect that many of the same concerns about size and mass currently would likely be vocalized if the city was proposing to re-adopt its existing code. The table below provides a summary.

Existing R-1Existing R-2Existing R-3Proposed R-A
Lot area per unit (min)4,000 SF2,500 SF3,000 SFNone
Lot width (min)50’50’40’25’
Building coverage (max)40%40%40%40%
Front setback (min)15’15’15’10’
Building height (max)40’40’46’3 stories
Wall plate height (max)NoneNoneNone25’
Building size (max)10,000 SF10,000 SF10,000 SF10,000 SF
Parking (min) – 1-bedroom unit1 space1 space1 space1 space
parking (min) – 2+ bedroom unit2 spaces2 spaces2 spaces2 spaces

The current approach to zoning essentially defines differing ratios of much land is required for each unit of housing. Higher zoning designations (e.g. R-4, R-5) have lower ratios of required land to housing units and allow additional types of housing (e.g. four-plexes are allowed in R-3 but not in R-2). A single housing unit could be a 500 SF shotgun house or a 5000 SF 10-bedroom mansion. Both require the same amount of land under our current code. As a result, because land is expensive, smaller types of housing have been effectively zoned out, with the exception of high-density apartment buildings.

While some missing middle housing types are allowed in R-2, R-3, R-4, and R-5 areas, they increasingly don’t economically pencil out to build. These smaller types of housing, e.g. duplexes, rowhouses, cottage courts, etc. are more affordable than single-family houses, and often provide a first-step on the equity ladder for a younger household, a downsizing option for older households, and rental options for young professionals.

This “zoning out” of smaller, more affordable types of housing (even while buildings which seem out of scale or out of character for the neighborhood get built) is what the new code is intended to address. For example, in R-1, a three-story 10-bedroom house could be built and rented out to ten college students but the same building envelop could not be legally used for a duplex for two families. Some neighbors in the Bon Ton and University districts have complained about the conversion of existing homes into college rentals, even while zoning prevents those existing houses from being converted into something that might be affordable to a younger family who might live in the neighborhood permanently.

Rather than a ratio of how much land is required for each housing unit, the new code describes allowable forms within a given zone, in terms of height, width, lot coverage, and space between units.

In the new “R-A” zone, buildings are expected to generally match the form of Bozeman’s traditional neighborhoods. Buildings should have the mass and appearance of houses, with lawns and yards, and space between lots. Building height is limited by the wall facing the street, which cannot exceed 25’ in height, and the footprint of the building cannot cover more than 40% of the lot. For a typical 5,000 SF lot, this means the maximum allowable building footprint would be 2,000 SF, and from the street you wouldn’t see a vertical wall of more than two-and-a-half stories in height.

A house with trees and grass

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The structure shown above is a 3750 SF (including basement) single-family house. Under the proposed code, this structure could contain four 950-SF two-bedroom units and look identical from the street. According to Zillow, the estimated monthly payment to purchase the pictured house would be $9,666 per month. Divided into four units, this cost would still be $2,400 per month. While $2,400 per month still isn’t affordable to many, that doesn’t support a counterfactual argument that, therefore, this house should be legally required to remain a single-family house.

The goal of the proposed code is to make it feasible and economical to develop “middle density” types of housing. It’s reasonable to expect that the resulting development patterns would resemble Bozeman’s traditional and historic neighborhoods, while creating attainable housing and opportunities for the next generation of Bozemanites in the process. While the new code promotes infill, it insists that infill must be gentle, hidden, or invisible.

If you’re supportive of Bozeman being a compact city that also offers opportunities for the next generation but have concerns about some of the specifics of the proposed code, please participate in the conversation by submitting comments to or attending an in-person event (e.g. the Community Development Board hearing in October). Nothing about the current proposed code is set in stone. Comments that adjust the code to make it fit and feel better (e.g. perhaps R-A should combine only R-1 and R-2 and limit height to two stories) will likely accomplish more than declarations of absolute opposition.

About Mark Egge

Transportation planner-adjacent data scientist by day. YIMBY Shoupista on a bicycle by night. Bozeman, MT. All opinions expressed here are my own.
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