Aspen City Hall.
Austin Colbert/The Aspen Times
Aspen City Council said it would like to receive additional information regarding the use of heat tape in commercial buildings, but overall council members said they tend to favor changing the current exemption.
Monday's work session was an opportunity for staff to follow up on council's interest in discussing two aspects of the Renewable Energy Mitigation Program (REMP) that include heat tape and outdoor heating within dining spaces, and how each may impact commercial properties.
Heat tape is a protective cable that is typically installed on gutters and roofs to prevent ice dams from forming on the edges of the roof. One of the questions staff wanted City Council to ask was whether the REMP regulations for commercial heat tape would still require the 100% offset that was approved by City Council through Ordinance No. 1 last January and allowed for the expansion of the existing REMP program.
Under the current exemption, the first 1,000 watts of heat tape used on a commercial building do not require a renewable energy offset, according to Planning Review Manager Dennis Murray, and the exemption is based on one adopted by Pitkin County in 2018. Among the alternatives presented, council members indicated they would like to consider an exemption based on the number of linear feet of roof edges and valleys that flow down into a public walkway.
REMP was established in 1999 to offset the energy use of outdoor amenities such as snowmelt water, pools and spas by requiring either a comparable on-site renewable energy system or a payment option to fund community renewable projects.
As stated in the staff memo, the primary reason for adding heat tape to the REMP is the energy use of the tape. According to the example provided, the annual energy use of 6,000 watts of heat tape (1,000 ft x 6 watts/ft) is similar to 200 square feet of melted snow. Staff suggested that applying the REMP to heat tape would encourage the use of only the amount of tape needed for a given space, encourage design and maintenance improvements, and reduce tape usage overall.
Councilman Bill Gass questioned whether there were currently proven alternatives to heat tape, explaining that this is an issue with older buildings and that newer buildings are less of an issue as they have the benefit of being built with better standards, materials and construction techniques.
Murray responded by saying heat tape is not the best or only solution to ice dams, adding that heat tape often makes the problem worse if its placement or roof design doesn't allow the melted snow to run off the roof before it refreezes.
He pointed to a study attached to the memo outlining how new construction, including airtight ceilings, insulation and under-deck ventilation using outside air, would ultimately help best avoid the problem. The study the staff referred to suggested an alternative: building a second ventilated roof on top of the existing roof.
Gass expressed concern about the high costs associated with building a new roof over an existing one, and further questioned whether it would be possible in Aspen given height restrictions and other variables. Councilman Ward Hauenstein said a foot-by-foot exemption makes the most sense, but added that he would like to hear about the cost aspects associated with cold roof construction.
Community Development Director Ben Anderson said in a statement that staff will be bringing additional information and proposed amendments to the City Council regarding the amount of heat tape that would be exempt.
After discussing heat tape, the council decided that a permit would not be required for portable outdoor gas heaters, which are commonly found in many Aspen restaurants in the downtown core.
To contact Jonson Kuhn, email jkuhn@aspentimes.com.