A trend over the past decade toward larger homes that consume more energy and generate increasing demand for services — along with a study showing that residential buildout in unincorporated Pitkin County is no more than about halfway complete — is driving the county’s interest in placing stricter caps on the size of new residential properties.

Pitkin County commissioners last month slowed a process intended to rewrite residential zoning codes after preliminary proposals gave rise to strong opposition from community members involved in real estate development. The proposals were the work product of a public-outreach committee that had been meeting online with staff from the community development department since June, with the mission of proposing changes to the land-use code both to reduce the climate impact of the residential sector and to take a fresh look at the system the county uses to evaluate the impact of such development.

Reducing allowed home sizes has been on the county’s radar since at least 2019 when commissioners declared a “climate emergency” because the larger the home, the more intense its impacts are related to energy use, landfill waste and ongoing demand for services. But addressing these impacts is complicated because the second-home industry is a huge economic driver in Pitkin County.

Some of the potential changes put on the table by the committee include reducing the size of a home that could be built by right — which means without having to compete for limited development allotments or purchase transferable development rights — from 5,750 square feet to 3,250 square feet. The committee also would like to make cuts to the maximum home size allowed, which in most areas of unincorporated Pitkin County stands at 15,000 square feet. The committee also called for stronger inducements toward net-zero-energy homes and changes that could limit the use of transferable development rights, or TDRs, or eventually sunset the program entirely. TDRs promote conservation in some areas by allowing greater development on other sites.

County staff is now working on ways to get more input through a renewed public process and will propose options to the county commissioners no sooner than January.

“This will resonate loudly with anyone who is a homeowner in Pitkin County,” said Randy Gold, an Aspen-based real estate appraiser who believes the policy options proposed are “too simplistic” and would benefit the holders of existing large properties at the expense of locals with modest homes, whose nest eggs are tied up in the land value. “There are a lot of people in that boat, a lot of working families.”

Providing context for the county’s effort are analyses of residential building trends over the past 10 years and projections of how much additional development the community can expect before “buildout” is reached.

Gabe Preston, principal of Durango-based firm RPI Consulting, which produced the buildout study for Pitkin County, said he applauds the county’s efforts to project development impacts decades into the future. His 2018 study of the impacts of residential home size focused particularly on the landfill and county roads and was used to inform discussions about upgrading the airport.

“If these core facilities get maxed out and you have to borrow a bunch of money, or if quality of life suffers, that affects everyone, regardless of how you feel about it,” Preston said. “If you don’t do anything about it, you’ve made a decision by default — you decided not to deal with it. The county is forcing themselves to take a step back and make a decision about the future.”

Greater impacts as home sizes grow

“Development in Unincorporated Pitkin County from 2010-2020,” a document generated by Pitkin County staff and shared with the public-outreach group, shows that the size of the average home over the past 10 years in Pitkin County is 5,120 square feet, while the average home size since the 1960s is 3,342 square feet.

Larger projects, while fewer in number, are responsible for the majority of newly built square footage, according to the analysis. A total of 253 new homes have come online in unincorporated Pitkin County since 2010, amounting to 1.29 million square feet. Sixty-five percent of those new homes have been smaller than the by-right limit of 5,750 square feet. However, the 35% of homes that are larger than that threshold account for 65% of the new square footage, according to the analysis.

“This reflects the majority of impacts and intensity of development seen coming from a minority of the projects,” says the document, which further details that the 11 residential properties built over the past 10 years that are each greater than 13,250 square feet represent 4.2% of new home starts but 12.5% of total new square footage.

Just over half of the new starts involve demolition of an existing home, according to county records. That is driving a spike in construction and demolition waste flowing into the Pitkin County landfill, where capacity is limited.

A study produced for Pitkin County that is referenced in outreach committee materials using 2014-17 data supplied by electric utility Holy Cross Energy and natural gas provider Black Hills Energy for 900 local homes shows that residential properties consume more energy per square foot as they get bigger, up to 13,000 square feet. A 2,000- to 3,000-square-foot home consumes about 40 kilo-British thermal units per square foot, while a 12,000- to 13,000-square-foot home eats up 110 kBTUs per square foot, according to the 2018 analysis by Resource Engineering Group of Crested Butte. (A kBTU is 1,000 BTUs, and a BTU is the amount of heat required to raise the temperature of 1 pound of water by 1 degree Fahrenheit.)

Based on the sample size analyzed, the average 13,250-square-foot home uses 1.38 million kBTUs per year. Although such a home is more than four times as large as a 3,250-square-foot home, it uses, on average, almost eight times as much energy, based on the data studied. Officials posit this is because larger homes have more energy-sucking amenities, such as heated driveways, patios and pools, as well as more appliances inside the house.

Pitkin County earlier this year passed new energy-efficient building codes that aim to reduce energy consumption by 70% for new homes. However, planners note that the new rules will do little to impact “embodied energy” — which is the amount of energy generated by the sourcing, manufacturing and transportation of building materials — and the home’s overall carbon footprint, which includes factors such as waste delivered to the landfill and ongoing services the home requires.

The total carbon footprint of an average 15,000-square-foot house, according to a county analysis, is 917 tons of greenhouse gases in its first year (including emissions associated with construction and demolition) and 79 tons every subsequent year. A 3,250-square-foot home produces 191 tons of greenhouse gasses in its first year, including construction, and 10 tons annually after that.


A 12,500-square-foot home located off of Midnight Mine Road in unincorporated Pitkin County. A study conducted for the county in 2018 found that homes use more energy per square foot as they get larger, up to 3,000 square feet. Credit: Curtis Wackerle / Aspen Journalism

Potential outcomes vary widely

Given these trends and the more intensive impact of larger homes, how much or how little Pitkin County limits future home sizes will have wide-ranging impacts on factors such as energy consumption, new jobs generated, and construction and demolition waste that could fill up remaining capacity at the landfill.

Preston and RPI’s study breaking down how much more residential development is possible in unincorporated Pitkin County found that if the 15,000-square-foot cap was realized on all potential new homesites — including vacant lots and lots that could be created in new subdivisions — and if all sites containing existing homes were redeveloped to their maximum allowable square footage, an additional 32.4 million square feet of residential development could take place in unincorporated Pitkin County.

If house size is limited to 5,750 square feet, the total potential coverage from new homes and redevelopments would be 11.6 million square feet, according to RPI’s buildout analysis.

The calculations are based on 1,267 potential new homesites, which include existing vacant lots and an assumption that all parcels that could be subdivided eventually would be, and that they would be built out to 60% of maximum allowed density. The study also assumes there are 1,700 homesites in the unincorporated county that could grow beyond existing square footage via redevelopment or expansion. The maximum buildout scenario shows roughly 16.4 million square feet coming from new homesite construction and 16 million square feet from redevelopment.

Currently, there are 3,860 primary residences in the unincorporated county, according to community development calculations, totaling 12.9 million square feet. Based on RPI’s buildout calculations, that means existing square footage amounts to 53% of the total possible if the future home-size limit is 5,750 square feet and roughly a third if the maximum buildout happens.

“By having this type of projection, the community is able to make critical decisions to ensure that infrastructure capacity meets the future desired needs of the community,” county planning staff wrote in an email. “By exploring these projections, the community is able to evaluate the scale, magnitude and costs of development and thereby determine what levels of development are appropriate when attempting to balance infrastructure needs, costs, community character and quality of life.”

The RPI analysis calculated the implications that either end of the buildout spectrum would have on new employees generated, how fast the county landfill would reach capacity, and wear and tear on county roads.

County housing studies have pegged the amount of ongoing employment — including landscaping, housekeeping and other service jobs — that are generated by a 5,750-square-foot home at 0.23 full-time-equivalent (FTE) employees. A 15,000-square-foot home generates 1.38 FTEs.

“Because employment increases exponentially with the size of a home in the unincorporated county, full residential buildout … would result in over 3,000 (employees) but buildout of exempt floor area up to 5,750 square feet would result in about 460 (employees),” says the RPI study.

At the landfill, known as the Pitkin County Solid Waste Center, construction and demolition materials from all jurisdictions have been taking up an increasing proportion of the waste stream, overtaking municipal solid waste each year between 2013 and 2017, according to PCSWC data referenced in the RPI study. Over the past 10 years, construction and demolition activities have sent roughly 40 million tons of waste to the landfill.

In 2017, remaining existing capacity at the landfill was about 1.2 million cubic yards, according to data cited in the RPI study. A 900,000-cubic-yard expansion of the landfill is in the planning stages. Since larger homes result in more construction and demolition waste, buildout at the maximum-allowable levels would generate 3.4 million cubic yards of waste, far exceeding both the existing capacity and the planned expansion. Buildout to the 5,750-square-foot limit would generate 1.3 million cubic yards — filling up the current landfill but not the expanded capacity.

RPI’s study also calculated that truck traffic associated with construction would generate the wear-and-tear equivalent to three new county roads at maximum buildout, while the 5,750-square-foot limit would consume the equivalent of just more than one county road.

Caveats on maximum buildout

Gold, the appraiser, and local planner Glenn Horn, when asked to evaluate the buildout-analysis conclusions, said the high-end estimations were not realistic. It is not reasonable to assume that all properties that theoretically could be built to 15,000 square feet will be, they said, thanks to the growth-management quota system, which is the scoring method that the county uses to allocate new square footage. That system prioritizes development that is below maximum-allowable density.

Horn, an expert on county land-use regulations as they relate to residential properties, said he would use a range of 9,000 to 12,000 square feet to estimate “worst-case” scenarios.

Both said they thought a reduction of the existing 15,000-square-foot cap could be reasonable, but it should be coupled with policies that incentivize smaller, more energy-efficient homes, as opposed to draconian caps.

Preston, the lead author on the RPI buildout study, said planning exercises are often theoretical and should be taken with a grain of salt. Because of the decadeslong time frame over which buildout would happen, one can never know what the future will hold.

“It is almost guaranteed to be something different than you think,” Preston said.

Even so, there is value in projecting what could happen under existing regulations, and examining how effective existing policies are in protecting community values, he said. Shared facilities such as the landfill, the airport and rural roads are the county’s responsibility, he said, as are regulations to ensure that those facilities are sustainable into the future.

“From my perspective, the notion that you have a county government looking at this, taking a leadership role and trying to figure out (how) growth trajectories … (will impact) the facilities they are responsible for — I think we need to do a lot more of that in Colorado,” Preston said.

The economy we want

Michael Miracle, the Aspen Skiing Co.’s director of community engagement who took an active role in the county’s outreach meetings over the summer, said the conversations addressing the impacts of the residential sector are critical to the community’s future and are long overdue.

He argues that the second-home industry has been the primary driver of local growth over the past two decades. Skier visits have remained flat and there hasn’t been a radical change in the number of new hotel rooms available, yet based on bus-ridership numbers and daily traffic coming across the Castle Creek Bridge on State Highway 82, more people are here. Miracle believes most of those additional people are tied to the growth of the residential sector, whether they are construction or service workers, folks working in real estate and planning fields, or occupants of the homes.

“It is hard to find a household where someone isn’t connected directly to this huge residential sector in some way,” he said.

Preston also is taking note of the economic implications that are playing out due to the growth of second homes.

“One of the interesting things about that industry, from an economic perspective, is that it is definitely a place where small businesses entrepreneurs can make a go,” he said. “It’s very dispersed. … You have an industry where you get a proliferation of small entrepreneurial outlets that are filling needs. There are not a lot of examples where you have that much wealth fragmented among so many individuals.”

The county, as part of its ongoing analysis of potential changes to home-size regulations, is gathering data from the state on the impact of jobs related to residential development, for both the Pitkin County and regional economies.

Preston believes that data will show far-reaching impact.

“When you get that much capital flowing out of that many different points of origin, that’s going to be fueling economic activity” far beyond the boundaries of Pitkin County, he said. “Is that good or bad? I don’t know, but it sure is fascinating to think about and witness.”

Miracle said there is no doubt the impact of these economic changes is considerable.

“We should be looking at this through a bigger community character lens and say: Is this the economy we want?” Miracle said.

He pointed to an example in Aspen’s Shadow Mountain neighborhood, where the parcel formerly occupied by the Boomerang Lodge, which was demolished in 2006, has sat empty as multiple developers have tried and failed to get a new hotel built. Meanwhile, “look at what is getting carved into the base of Shadow Mountain,” Miracle said, referencing a handful of large homes — which are just over the Aspen city-limit boundary and under Pitkin County’s jurisdiction — that have recently come online or are under construction. “That is lodge-like in its scale.”

While land-use applications for large commercial projects tend to attract the most community angst, the growth of the residential sector has flown under the radar, Miracle said, because there is little public process associated with an individual application for a large home.

“What the county is doing now is the public land-use process for the whole sector, which hasn’t happened for 20 years,” he said. “No one has said, ‘What do we think this is going to do to us going forward and how comfortable are we with that?’ And this is that process. But it has come so late in this shift of what makes up our economy that now so many people have their personal livelihoods wrapped up in it, that it is hard to look at it objectively.”

Go from here

Horn, the local planner, said officials should hold off on moving any new residential-zoning regulations forward until the county can run a “valid planning process.”

“I don’t see this as a crisis situation,” Horn said, questioning why the public outreach had to take place this summer when COVID-19 restrictions prevented in-person meetings. “I think it can wait until we can meet in person again.”

Cindy Houben, the director of the county’s community development department, said that the recommendations that came out of the outreach committee were not definitive and, in two meetings this fall before commissioners were recommendations were presented, staff was looking for direction. While staff initially proposed a schedule that would have seen the first land-use code rewrites brought forward before the end of the year, Houben said that staff “got ahead of itself” and was merely telling commissioners what was possible from a timeframe standpoint.

Still, it is important to note that while the residential-zoning revisions are in a holding pattern as COVID-19 slows down the public process, property owners are applying for development permits at a feverish pace.

“Every time you stop because of COVID, you lose ground,” Houben said. “When you look at climate action, that is not stopping.”

After the county commissioners’ Oct. 6 meeting, where the board heard dozens of comments challenging the process to date, commissioners agreed that more public outreach needed to happen but held firm to the principle of the effort.

“I didn’t hear from anyone that we should stop this discussion or reprioritize climate action, which the community values,” Commissioner Kelly McNicholas Kury said at the end of the meeting. “This is a messy space, but I know we are going to move through it together.”

This story ran in the Nov. 15 edition of The Aspen Times.


Curtis Wackerle is the editor and executive director of Aspen Journalism and the editor and reporter on the Connie Harvey Environment Desk. Curtis has also served as editor, managing editor, and reporter...