Boulder County’s Planning Commission has voted unanimously to reject a proposal that would permanently limit the size of new homes in unincorporated areas of the county. The decision is a potential setback for county commissioners who see the proposal as a way to address housing affordability and curb the environmental impacts of oversized homes.
The nine-member volunteer board, which advises the county commission on land-use matters, also recommended lifting the temporary moratorium on large homes that commissioners enacted last fall. The moratorium, approved in September, bars the construction of homes that exceed the median size in a given neighborhood. It is expected to remain in place through July 17 unless county commissioners decide to end it sooner.
The proposed revisions to the county’s site plan review rules would make that restriction permanent, with limited exceptions. Before the moratorium, property owners were allowed to build homes up to 125% of the neighborhood median and could seek approval to go even larger. County officials have said this policy has led to increasing home sizes.
A public hearing before the Board of County Commissioners has not yet been scheduled. Commissioners will have the final say on whether to adopt the proposed changes.
At a hearing last week, Planning Commission members said they generally supported the county’s broader goals to lower housing costs and reduce environmental impacts. But they questioned whether the proposal would effectively accomplish those goals. Several said current regulations seem to be working well. Others said the county should consider tying maximum home size to lot size, rather than neighborhood averages, through the creation of zoning districts. Architects have raised concerns that tying home size limits to neighborhood medians benefits homeowners in wealthier areas, where houses tend to be larger.
Some said they would be more likely to support stricter limits on home sizes if paired with looser rules for accessory dwelling units, or ADUs, to allow more flexibility for property owners, including those who want more space to work from home, homeschool their children or live with aging relatives.
“There’s a really good foundation here,” Chris Whitney, chair of the Planning Commission, said of the proposed changes during last week’s hearing. “But as long as we’re opening this conversation up, I feel like it would be the opportunity to take it a step further.”
County staff said they are already working on changes to the county’s ADU regulations, which are currently far more restrictive in unincorporated Boulder County than in places like the City of Boulder, in part due to concerns about adding housing density in rural areas with limited services.
Implementing zoning districts — another idea floated by many Planning Commission members — would likely be complicated. Ethan Abner, a county planner working on the site plan review reforms, said Boulder County’s diverse geography presents challenges. For instance, lots on the eastern plains are large and rectangular, while lots in the mountains are narrow and sometimes divided by mining claims.
“Floor area ratios are easier to implement when the lots are uniform in size,” he said, referring to a zoning metric commonly used in cities that ties the allowable home size to lot size. “That’s a challenge that we have with our regulations. We’re trying to implement a system that works for both mountainous areas of the county and the plains.”
Abner said the county commissioners may consider the proposed site plan review changes as soon as April.

So the Commissioners directed county staff to come up with a proposal to create a more permanent solution to a current moratorium purposely designed limit the building of bloated, oversized homes; and Planning Board instead completely rejects the original underlying premise and now suggests stepping in the complete opposite direction to further loosen restrictions? Ugh, I guess that tracks with the current Planning Board membership; which has itself become bloated with special interest “volunteers” like architects (Whitney, Lee, Manna, Libby), building consultants (Bloomfield), real estate development firms (McMillan), and others whose professional careers are potentially direct conflicts-of-interest here.
Lest folks not also forget how the current Planning Board members McMillan, Bloomfield, Whitney, and Libby lined up to set a dangerous president to dismantle an established (40-year!) agricultural Conservation Easement to allow the Kanemoto subdivision to be built; thus sending the message that honoring the explicit preservation of lands as open spaces remains a far lesser priority than allowing new high-density development. So let’s not be confused about their actual “goals”, tricked by their ongoing rhetoric regarding “affordability”, nor distracted by anymore ADU strawman discussion…particularly because the Colorado legislature has already usurped their local authority and is creating state-wide regs.
I participated in this meeting and have a very different take on thinks. Through out the all the public input portion of this process, the input from citizens of BoCo has been overwhelmingly (like 95%+) against both the moratorium and the changes to site plan review. The planning commission is the first group to acknowledge that the constituency is not in favor of this change.
The reasons for this vary, some are architects/builders who see that this will impact their business, and while I am sympathetic, I don’t see this as a particularly compelling reason. Some are home owners who have had long standing dreams of either building or remodeling a home and this change completely upends those dreams, I find this more compelling.
Finally some are just residents of Boulder County who see the enormous inequity in the Site Plan Review process, and that this would only make that worse. As it is, if you live in a wealthier area of the County with larger homes, you can build a larger home because the limit is the median of your neighbors – even with the change there would still have been many neighborhoods where you could build a 6000+ sq ft home. However, if you happen to live in a less affluent area, where the surrounding homes are smaller (think Ward, Marshall and other historic areas) you could be limited to as little as 2500 sq ft. Note that this includes garages, sheds, unfinished basements, workshops etc, so actual conditioned living area may be 1000 sq ft. This just reinforces existing inequities – rich people can continue to build huge houses, and less well off are even further limited in their ability to catch up. If the county wants to limit home sizes, put a flat limit in place that limits *all* residents equally, don’t pick winners and losers.
It will be interesting to see where the commissioners go with this. Will they ignore the will of the people and the Planning Commission and pass it anyway? Will they tweak the ordinance and try again? Or will they give up on this all together?
How does preventing the construction of “bloated and oversized” homes on 30 acre lots help any of the rest of us in Boulder County? Is is feel good? I would love to have the impact on my property taxes quantified.
I struggle to believe that the construction of a single 6000 sq. foot home down the street from me contributes more than a de minimis amount to my taxes than the overall market trends in Boulder. And of course if that’s the problem, then how property taxes are calculated could be changed (add a surcharge for homes over 4500 sq. ft certain size!)
I really struggle to understand why the Commissioners are wasting their time on this in the first place. The ADU discussion is super pertinent at that have a much more significant impact on affordable rentals than whether someone builds 4500 sq feet or 6000.
Whatever the outcome of this squabbling and technical language massaging is, If a board can tell me “no” to a barn a size I (alone it’s my land) deem appropriate (regardless of my home size already) on 50 acres surrounded by 2000+ acres of Nat Forest because there is an 1880’s gold mine shack next door ( a mile away) then that will be a serious overreach and I might have to get a Sherman tank.
The planning commissioners’ hearing where this was discussed was actually an excellent example of how good governance works. Back on September 17th, The County commissioners asked staff to investigate ways to reduce allowable house size. Over the last six months staff has done that and has met with dozens of stakeholders to hear everyone’s perspectives and concerns. I was among one of those small groups that met with staff and staff should be applauded for doing their job professionally, diligently and thoughtfully. That said, the commissioners are their actual bosses and the final proposal didn’t really change much from the commissioners’ initial request to reduce all new houses to the median size in their neighborhood – however, this went against the overwhelming public opinion which was to leave the already extremely strict rules as they currently are and not further restrict what people can do with their property. Staff presented their proposal to the planning commission and the planning commission disagreed with the county commissioners and staff’s proposal – stating that they felt that this was a solution in search of a problem. Or more specifically, that while everyone in the room agreed that affordability, sustainability and neighborhood character are important shared values, the planning commission did not see that these proposed rule changes would effectively accomplish those goals and saw other opportunities to do so in a better way. Everyone in the room acknowledge what an incredibly difficult task it was to try and balance all of these priorities simultaneously. The 4 1/2 hour discussion that followed was civil, informative, and filled with curiosity and respectful brainstorming.
At the end of the day the county commissioners get the last word and can still implement the proposed new rules.
The county has the authority to periodically change the rules for planning and zoning. What’s notable about this proposal is that the county commissioners decided to enact a moratorium on all new housing applications larger than the median size while they consider the new rules – which is typically an extreme action reserved for emergencies. As numerous members of the public and the planning commission expressed, there is no actual emergency happening right now. And second, they are proposing a very significant rule change and reduction in the size of allowed homes, but the public largely doesn’t seem to be aware that this is happening; those that are aware have come out in near unanimous opposition to the commissioners request. Fortunately, the planning commission heard that strong opposition and shockingly sided with the opinions voiced by the community. 
One particularly good thing that came out of the exhaustingly Long discussion was the unanimous and strong support for accessory dwelling units to be allowed on all county properties. This is something that the county has been considering for a few years, but it seems like this could be a moment where that finally happens. Note that the state’s new law allowing A.D.U. ‘s everywhere does not apply to unincorporated Boulder County. It only applies to Incorporated municipalities so while the reasons for the new state law apply just as much to Boulder County as it does everywhere, it’s up to the county commissioners if they choose to follow suit with the state. The benefits of ADU’s that are that they create small, affordable, sustainable dwelling Units, and equitably allows all properties, no matter if they are in a neighborhood with large houses or small houses, to all have one. This is the single most effective way to address the county commissioners’ overall concerns. Let’s hope they get this done soon. It would benefit all of Boulder County.