Housing Mitigation Requirements in Chittenden County, Vermont

Burlington's Inclusionary Zoning: 15-25% affordable, triggered at 5 units, price-controlled for 99 years

Burlington adopted its Inclusionary Zoning ordinance in 1990, making it one of the first cities in the United States to require developers to include affordable units as a condition of building larger residential projects, rather than waiting on a state or federal mandate. As currently administered, the ordinance requires a base of 15% of units in a covered project to be designated affordable, rising toward 25% depending on the average price of the project's market-rate units -- the higher percentage applies to the most expensive developments. It applies to new construction of five or more units and to the conversion of buildings with more than 10 existing units. Affordable units are targeted to households earning roughly 70% or less of area median income (AMI) for homeownership units, or 65% or less of AMI for rental units, and the price or rent restriction runs for 99 years -- effectively permanent for underwriting purposes.

The ordinance isn't a fixed, unchanging rule: in March 2023, the Burlington City Council unanimously amended it (ZA# 23-02) to give developers more flexibility in how affordable units are counted, specifically loosening a prior requirement that the bedroom mix of affordable units match the bedroom mix of market-rate units one-for-one (so, for example, a project heavy in market-rate three-bedroom units no longer has to match that ratio in its affordable units). That kind of technical amendment is common for a 30-plus-year-old ordinance, and it means a developer or buyer evaluating a Burlington multi-unit site should confirm the currently-in-force version of the requirement rather than relying on an older summary.

South Burlington runs its own, separate inclusionary zoning rule -- not the same as Burlington's

South Burlington, Chittenden County's other large city and Burlington's immediate southern neighbor, has its own inclusionary zoning requirement, and it is not the same rule as Burlington's next door. South Burlington's version applies specifically within designated districts -- including its City Center Form Based Code District, its Transit Overlay District, and certain lands near Hinesburg Road -- and its numeric trigger has generally applied to developments of 12 or more residential units, a meaningfully higher unit-count threshold than Burlington's 5-unit trigger. A project just over the Burlington/South Burlington line can therefore face a materially different affordable-housing obligation (or none at all, if it falls under the applicable unit threshold or outside the mapped overlay district) purely because of which city it sits in.

The practical takeaway for anyone evaluating multi-unit residential land in either city: don't assume Chittenden County has one countywide inclusionary zoning standard, and don't assume a rule you've seen cited for Burlington applies unchanged to a South Burlington parcel, or vice versa. Both cities' requirements are also subject to periodic amendment, as Burlington's March 2023 change shows, so treat any specific percentage or unit-count threshold as something to reconfirm with the specific city's planning department before pricing a project.

What to check before buying multi-unit residential land in Burlington or South Burlington

1. Confirm which municipality the parcel is in -- Burlington and South Burlington run separate, non-identical inclusionary zoning ordinances, and being a short distance from a city line does not tell you which rule, if either, applies.
2. In Burlington, confirm the project's likely unit count against the 5-unit (new construction) or 10-unit (conversion) trigger, and get the current set-aside percentage (15% base, up to 25%) and AMI targets (roughly 70% ownership/65% rental) directly from the Planning & Zoning department, since the ordinance has been amended before and can be amended again.
3. In South Burlington, confirm whether the parcel sits inside the City Center Form Based Code District, the Transit Overlay District, or the Hinesburg Road area where inclusionary zoning applies, and confirm the current unit-count trigger (historically 12+) directly with the city's planning office.
4. Factor the 99-year affordability price-restriction into any pro forma for a Burlington project -- inclusionary units are not a one-time design cost, they're a multi-generational income and resale restriction on a portion of the building.
5. Ask each city's planning department whether an offsite mitigation-payment or fee-in-lieu alternative is currently available instead of building the affordable units onsite, since inclusionary zoning ordinances in some Vermont municipalities allow this option and terms vary by city and by amendment.