"Should property in Boulder work for the people who live here, or just the people who own it?" That line came from Jill Grano, a former Boulder city councilmember, back when she was collecting signatures for a citizen-led vacancy tax. Her campaign eventually stood down. The city council picked up the idea instead, and in August 2026 voted 7 to 1 to send a residential vacancy tax to the November 3 ballot. If it passes, the tax takes effect January 1, 2028.
Most coverage of this measure has focused on the politics: who voted no, what it means for downtown storefronts, whether it will actually free up housing. Buried underneath that story is a mechanic that matters more to anyone closing on a Boulder property in the next two years. The tax is not going to be enforced by someone driving around checking if your lights are on. It runs on paperwork. Your driver's license, your voter registration, your spouse's mailing address, and what the Boulder County Assessor has on file for you. Get those four things out of alignment and the city will presume your home is vacant, whether or not anyone is actually sleeping there.
What council actually referred to the ballot
The measure, Ordinance 87-59, applies to any home occupied 183 days or fewer in a calendar year. It starts at $4,000 per unit per year, climbs with the Denver-Aurora-Lakewood consumer price index, and caps at $7,000. The city estimates it will affect somewhere between 500 and 1,000 properties and generate roughly $4 million to $6 million a year once fully phased in, with the money going toward general city services rather than a dedicated fund.
| Detail | |
|---|---|
| Ballot date | November 3, 2026 |
| Effective date | January 1, 2028 |
| Occupancy threshold | 183 days or fewer per year |
| Starting tax | $4,000 per unit, per year |
| Cap | $7,000, adjusted by CPI |
| Estimated homes affected | 500 to 1,000 citywide |
Mayor Aaron Brockett, Mayor Pro Tem Tara Winer, and Councilmembers Matt Benjamin and Rob Kaplan voted to refer the measure. Nicole Speer cast the lone no vote, arguing the timing risked undermining a separate downtown development proposal that ultimately failed on a 4-4 tie the same night. Both a progressive council faction and PLAN-Boulder County, groups that rarely agree on anything, opposed pushing the vacancy tax forward alongside that other measure. It passed anyway.
The four things the city will actually check
Here is where the measure gets specific in a way that matters if you are the buyer, not the political observer. The ordinance defines a principal residence as the dwelling where someone lives more than half the year. But it does not just take your word for it. If any of four conditions are true, the presumption flips to non-principal residence, meaning you owe the tax unless you can prove otherwise:
- You own another dwelling that is not licensed for long-term rental
- Your spouse or domestic partner lists a different address as their principal residence
- Your driver's license, voter registration, or a dependent's school registration shows a different address
- The Boulder County Assessor has a different mailing address on file for you
None of these are about whether you are physically present in the house on any given night. They are about whether your official paper trail agrees with your claim. A retired couple splitting time between Martin Acres and a winter place in Phoenix, a remote worker who bought in Boulder but has not yet switched their license over, a family whose adult child is still registered to vote at the old address, all of these could trip the presumption even in a home that gets real, regular use.
Why the city's own headcount kept shrinking
The number of vacant homes in Boulder has moved a lot over the past two years, and that movement tells you something about how uncertain the enforcement mechanics still are. A May 2024 city memo put the figure at roughly 4,000 out of Boulder's 48,000 housing units. By March 2026, when city staff reviewed water usage data as a proxy for occupancy, that estimate had fallen to around 500 single-family homes vacant for more than six months, with multifamily buildings excluded entirely because staff said the data was too hard to isolate.
That is not a small revision. It is an eightfold drop, produced entirely by a change in measurement method rather than any change in how many homes are actually empty. Water usage is an imperfect proxy too. A homeowner who runs their irrigation on a timer through the summer will show up as occupied whether or not anyone is home. The city has effectively built a tax around a population it still cannot count with much precision, using an enforcement test built on paperwork rather than the usage data that produced the estimate in the first place.
The renovation clock and the rental off-ramp
Two carve-outs matter if you are buying with plans beyond simple full-time occupancy.
A home undergoing active renovation is exempt from the tax for up to two years, with extensions available for documented good-faith progress. That is relevant for the small developer or investor buying a dated property with plans to gut and rebuild before resale or lease-up. The clock starts when the vacancy would otherwise be counted, so a renovation that drags past two years without visible progress on record could start accumulating the tax.
The other off-ramp is licensing the unit for long-term rental. A second home that is not your principal residence avoids the tax if it is licensed and actually rented on a long-term basis rather than sitting empty or cycling through short stays. For a downsizer weighing whether to sell an inherited property outright or hold it as a rental while deciding, this changes the math on holding versus selling in a way that is easy to miss if you are only looking at the sale-price side of the decision.
What this means if you are closing before 2028
The tax does not start until January 1, 2028, which gives anyone closing on a Boulder property in the next two years a real planning window rather than a surprise bill.
If you are buying a second home or a pied-à-terre, the practical move is aligning your paperwork before the effective date, not after. Update the driver's license, register to vote at the address you intend to claim as principal, and make sure the county assessor's mailing address matches. If your spouse or partner keeps a separate primary address for work or family reasons, understand that this alone can trip the presumption regardless of how much time you personally spend in the home.
If you are an investor or small developer buying with a renovation plan, document the timeline. The two-year exemption clock is generous, but it depends on being able to show progress, not just intent.
If you are relocating and buying ahead of a full move, meaning the home will sit lightly used for a year or more while you finish out a job or a school year elsewhere, this is worth factoring into your first-year ownership costs the same way you would factor in property taxes or insurance.
Longmont, fifteen miles away in the same county with a comparable budget and population, reportedly has less than half Boulder's vacancy rate. That gap is one reason city officials frame this measure as addressing a genuinely local condition rather than a general housing-market trend, and it is part of why the tax targets residential vacancy specifically rather than treating Boulder like every other Front Range city.
A few direct answers
Does this apply to condos and townhomes, or only single-family homes? The ordinance as referred applies to residential dwelling units broadly, not just detached single-family homes, though the city's early estimates focused on single-family data because multifamily vacancy was harder to measure.
What if I work remotely and travel more than six months a year? Travel alone does not trigger the tax if the home remains your principal residence under the ordinance's definition. The risk is in the four presumption factors: if your license, voter registration, spouse's address, or assessor mailing address point elsewhere, the burden shifts to you to prove principal residence status.
Is this tax final, or could it still change? Voters decide on November 3, 2026. If approved, the city still has to finalize implementation and enforcement details before the January 1, 2028 effective date, so specifics around documentation and appeals could still be refined.
If you are weighing a second home, an investment property, or a renovation project in Boulder and want to think through how this measure fits into your ownership plan before you write an offer, The Bernardi Group can walk through the timing with you. Start Your Strategy Session.
