Item 6B - 900 Baseline Rd. - Chautauqua Air Conditioning UnitsAgenda Item #6B Page 1
M E M O R A N D U M
June 6, 2018
TO: Landmarks Board
FROM: Lesli Ellis, Comprehensive Planning Manager
Debra Kalish, Senior Counsel, City Attorney’s Office
Marcy Cameron, Historic Preservation Planner II
James Hewat, Senior Historic Preservation Planner
Tony Wiese, Historic Preservation Intern
SUBJECT: Public hearing and consideration of a Landmark Alteration Certificate to
install an air conditioning system for six cottages on Astor Lane, a
standard air conditioning unit at Cottage 200, and a mini-split air
conditioning unit at the Academic Hall, all in the Chautauqua Park
Historic District, pursuant to Section 9-11-18 of the Boulder Revised
Code 1981 (HIS2018-00109).
STATISTICS:
1. Site: 900 Baseline Rd., Chautauqua Park
2. Zoning: RL-1 (Residential Low-1)
3. Applicant: Jeff Medanich, Colorado Chautauqua Association
4. Owner: City of Boulder
STAFF RECOMMENDATION:
If the applicant complies with the conditions listed below, staff considers the proposed
installation meets the standards of Section 9-11-18, B.R.C. 1981, Standards for Landmark
Alteration Certificate Application, and is consistent with the General Design Guidelines
and the Chautauqua Park Historic District Design Guidelines. Staff recommends that the
Landmarks Board adopt the following motion:
I move that the Landmarks Board approve the application for the installation of air condition
units as shown on plans and specifications dated May 10, 2018, finding that, if installed
pursuant to the conditions below, the air conditioning units will meet the standards for
issuance of a Landmark Alteration Certificate in Section 9-11-18, B.R.C. 1981, and will be
consistent with the General Design Guidelines and the Chautauqua Park Historic
District Design Guidelines and adopt the staff memorandum dated June 6, 2018 as the
findings of the Board.
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CONDITIONS OF APPROVAL:
1. The applicant shall be responsible for installation of the air conditioning system
and units in compliance with the approved plans dated May 10, 2018, except as
modified by these conditions of approval.
2. Prior to submitting a building permit application and receiving final issuance of
the Landmark Alteration Certificate, the applicant shall submit plans indicating
the design details for the type of air conditioning system for the Bachelder
Cottages that shall be reviewed and approved by the staff prior to the issuance
of a building permit. The applicant shall demonstrate that the design details are
in compliance with the intent of this approval and the General Design Guidelines,
and the Chautauqua Park Historic District Design Guidelines.
SUMMARY
• On April 18, 2018 the Landmarks Design Review Committee (Ldrc) referred the
application to install central air conditioning systems/units for eight Colorado
Chautauqua Association (CCA) owned buildings in the Chautauqua Park Historic
District. The basis of the referral was that a proposal to install a large air-
conditioning system at Chautauqua is unprecedented and the Landmark Board’s
consideration is necessary.
• Review by the full Landmarks Board in a quasi-judicial hearing is appropriate
pursuant to Section 9-11-14(b) B.R.C. 1981.
• Staff considers that if the applicant complies with the conditions listed below, the
proposed installation meets the standards of Section 9-11-18, B.R.C. 1981, Standards
for Landmark Alteration Certificate Application, and is consistent with the General
Design Guidelines and the Chautauqua Park Historic District Design Guidelines.
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Figure 1. Map of the Chautauqua Park Historic District with
location of proposed Astor Lane Cottage Air-Conditioning System
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PROJECT DESCRIPTION
The Colorado Chautauqua Association (CCA) requests permission to install four
heating, ventilation and air conditioning (HVAC) units to service eight buildings in
the Chautauqua Park Historic District that are owned or leased by the CCA and
operated by the CCA.
Figure 2. Location of three Air-Conditioning System locations (in red)
Figures 3. Proposed location of condenser at rear (north)side of c.1910 Cottage 503
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Three locations are proposed for the HVAC systems, the largest consisting of two
Mitsubishi high-efficiency condensers at the rear of Cottage 503 and Cottage 509 to
provide cooling and heating to the six cottages at the north side of Astor Lane (see
figures 2-4).
Figures 4. Proposed location of condenser at rear (north)side of c. 1901 Cottage 509
The second location at the west face of the c. 1900 Academic Building calls for
installation of a high efficiency ductless mini-split HVAC unit (see figures 2 and 5).
Figures 5. Proposed location of condenser at side (west) side of the c. 1900 Academic Hall
A standard air condensing unit is proposed to be installed at the north side of the 1882
Bachelder Ranch House (see figures 2 and 6).
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Figures 6. Proposed location of condenser at rear (north) side of the 1882 Bachelder Ranch House
Specifications show the Astor Place cottage and the Academic Hall HVAC units to be
“mini-split systems” supplying air conditioned and heated air to the buildings. Mini-
split systems are highly efficient systems, typically offering higher efficiency, reaching
above 30 SEER and producing 9,000 to 36,000 British Thermal Units (Btu) per hour of
cooling. The multi-zone system will provide extended cooling and heating capacity of
60,000 Btu for the six Astor Place cottages. Flexible exterior hoses are proposed to lead
from the outside unit to the interior ones on the Astor Cottage and Academic Hall;
enclosed to look like common drainpipes from the roof.
Product information for the split systems indicate that noise levels of each of the
condensers are in the range of 52 decibels (dBa), or about the same level as a normal
level of spoken conversation. The condensers are 37” high, 31” wide and
approximately 13” deep.
No details were provided for the proposed “standard air condensing unit” proposed
for the Bachelder Ranch House.
ANALYSIS
At staff’s request, the CCA has provided information on efforts at Chautauqua to
make its buildings as energy efficient as possible and to demonstrate the steps that
have been taken to make the cottages comfortable during cold and hot periods when
the use of HVAC systems is desired. Figure 7 outlines a chronology of cooling
strategies at Chautauqua from 1898 to the present day. See Attachment A: Applicant
Materials
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Figure 7. Chronology of Efforts to Building Cooling at Chautauqua
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Figure 7 indicates that since at least the 1940s, when cottages began to be used as year-
round housing by the university, a variety of strategies have been employed to achieve
climate control in the buildings at Chautauqua. This chronology also demonstrates
that from the 1970s on, there was a desire to make the Chautauqua more energy
efficient while utilizing green and natural technologies, such as insulating and
weather-proofing, and experimenting with whole house fans and swamp coolers
during hot summer months. These efforts coincide with a rising awareness of climate
change in the community and an increased utilization of buildings by the CCA for
short-term lodging. Currently, 58 of the nearly 100 buildings at Chautauqua are in use
as short-term lodging.
Figure 8. Map of cooling strategies (devices) at Chautauqua
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Currently 50 buildings Chautauqua are fitted with whole house fans while 14
buildings have traditional HVAC systems and 23 buildings have no cooling systems.
During the summer the Colorado Chautauqua Association installs portable air
conditioners in 58 units cottages used for lodging. Landmark alteration certificate
review is not required for portable window air conditioners or portable swamp
coolers.
Figure 9. Map of cooling strategies used in cottages & buildings at Chautauqua
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CRITERIA FOR THE BOARD’S DECISION
Subsections 9-11-18(b) and (c), B.R.C. 1981, set forth the standards the Landmarks
Board must apply when reviewing a request for a Landmark Alteration Certificate.
(b) Neither the Landmarks Board nor the City Council shall approve a Landmark
Alteration Certificate unless it meets the following conditions:
(1) The proposed work preserves, enhances, or restores and does not damage
or destroy the exterior architectural features of the landmark or the subject
property within an historic district;
(2) The proposed work does not adversely affect the special character or
special historic, architectural, or aesthetic interest or value of the landmark
and its site or the district;
(3) The architectural style, arrangement, texture, color, arrangement of color,
and materials used on existing and proposed constructions are
compatible with the character of the existing landmark and its site or the
historic district;
(4) With respect to a proposal to demolish a building in an historic district,
the proposed new construction to replace the building meets the
requirements of paragraphs (b)(2) and (3) above.
(c) In determining whether to approve a landmark alteration certificate, the
Landmarks Board shall consider the economic feasibility of alternatives,
incorporation of energy-efficient design, and enhanced access for the disabled.
ANALYSIS
1. Does the proposed application preserve, enhance, or restore, and not damage or destroy
the exterior architectural features of the landmark or the subject property within a
historic district?
Staff considers that, provided the conditions listed are met, the proposed
installation of a high efficiency split system HVAC units will not damage or
destroy the character of the Chautauqua Park Historic District.
2. Does the proposed application adversely affect the special character or special historic,
architectural, or aesthetic interest or value of the district?
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Provided the listed conditions are met, staff does not consider the proposed
installation of a high efficiency split system HVAC units will adversely affect
the historic, architectural, or environmental significance of the historic district.
3. Is the architectural style, arrangement, texture, color, arrangement of color, and
materials used on existing and proposed structures compatible with the character of the
historic district?
Staff considers that the proposal will be compatible with the historic character
of the Chautauqua Park Historic District.
4. Does the application incorporate energy-efficient design and enhanced access for the
disabled?
The installation of the proposed high efficiency split system HVAC units
incorporate energy efficient design meets this standard in that it is currently the
most energy efficient type air conditioning currently available.
DESIGN GUIDELINES
The Historic Preservation Ordinance sets forth the standards the Landmarks Board
must apply when reviewing a request for a Landmark Alteration Certificate and the
board has adopted the General Design Guidelines to help interpret the ordinance. The
following is an analysis of the submitted proposal with respect to relevant guidelines.
It is important to emphasize that design guidelines are intended to be used as an aid to
appropriate design, and not as a checklist of items for compliance.
Chautauqua Design Guidelines
Energy Conservation Measures
Some commonly used energy conservation measures include storm windows, porch enclosures,
insulation and solar panels . . . Adding insulation should be carefully so building material as
aren’t damaged . . . The preservation of natural ventilation of cottages in encouraged.
Adopted in 1988, this guideline acknowledges both the important simple camp-like
historic character of the district and the need to make buildings both energy efficient
and comfortable. The “preservation of natural ventilation of cottages” will not directly
be affected by the proposed installation of the proposed split HVAC systems. While it
can be argued that the increased use of air conditioning units may affect the
“lifeways” of Chautauqua during the summer by encouraging residents to turn on the
air conditioning rather than sitting out on the porches as was historically the case, it
cannot be argued that installing the split systems will have a direct effect on the
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character of the historic district for the following reasons:
As proposed the split systems are 37” high, 31” wide, and approximately 13” deep.
1. At this size, the 30,000 Btu condensers are relatively unobtrusive if
sensitively located and capable of cooling three average sized
Chautauqua cottages.
2. Product information indicates that the condensers are relatively quiet
when operating, with a sound pressure equivalent of 52 decibels that is
equal to a normal level voice conversation.
3. The units are detached from buildings and lightly linked via a low
profile flexible hose.
General Design Guidelines
8.2 Energy Efficiency
In 2006, Boulder’s City Council adopted a Climate Action Plan to meet the Kyoto
Protocol goals of substantially lower emissions of greenhouse gases. It is the city’s
aim to create compatibility between historic preservation and energy efficiency goals.
In the historic districts and on individually landmarked buildings it is important to
ensure that energy efficiency concerns are addressed in ways that do not damage or
diminish the historic character of the building, site or district. It is recommended that
before any energy efficiency upgrades are made a comprehensive energy audit is
conducted to determine the building’s current energy loss.
In historic districts, a variety of energy-conserving site and building features illustrate
the sensibility of an earlier era to climate and energy efficiency. Thoughtfully located
shade trees buffer residences and sidewalks from the summer sun. Projecting
porches provide shaded outdoor space and lessen the impact of the harsh sunlight on
the building's interior. Operable windows and shutters allow occupants to control the
introduction of sunlight and breezes within the buildings. An understanding of how
such historic features enhance energy efficiency is critical to maximizing the energy
efficiency of historic buildings.
For more information regarding the energy audit program and energy efficiency in
historic buildings, please contact the Office of Environmental Affairs at
www.environmentalaffairs.com.
Guideline Analysis Conforms?
8.2.1 Retain and preserve the inherent
energy conserving features of
historic buildings and their sites,
including shade trees, porches
and operable windows and
transoms.
Historic energy conserving
features of the buildings will not
be directly affected by the
proposal.
Yes
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8.2.2 Increase the thermal efficiency of
buildings by observing traditional
practices
All of the buildings proposed for
split system have had energy
audits and been made energy
efficient using traditional methods
such as insulation, weather
stripping and storm window
installation.
8.3 Mechanical and Utility Facilities
Guideline Analysis Conforms?
8.3.1 If a new mechanical system is
needed, install it so that it causes
the least amount of alteration to
the building’s exterior facades,
materials, and site features.
Proposal calls for installation of
external condenser units that are
discretely located and connected
to buildings lightly by way of
flexibles hoses. These units are
highly reversible.
Yes
8.3.2 Locate new mechanical
equipment and utilities, including
heating and air conditioning units,
in the most inconspicuous area,
usually along a building’s rear
façade. Screen them from view.
Proposal calls for installation of
external condenser units that are
discretely located and to be
screened by planted vegetation.
Yes
8.3.3 Where possible, locate portable
windows air-conditioning units on
rear facades or inconspicuous
side facades. Consider noise
impacts to neighbors when
selecting sites.
Proposed split systems will
replace louder and less energy
efficient window air conditioners.
Yes
8.3.4 It is not appropriate to install
ventilators, antennas, skylights,
satellite dishes or other
mechanical equipment in locations
that compromise character-
defining roofs, or on roof slopes
that are prominently visible.
Proposal calls for installation of
external condenser units that are
discretely located on the ground
and to be screened by planted
vegetation
Yes
Staff considers that the proposed installation of split air conditioning systems is
generally consistent with the General and Chautauqua Design Guidelines and meets the
standards for issuance of a Landmark Alteration Certificate pursuant to Section 9-11-
18 (b) & (c) of the Boulder Revised Code 1981. In the past, the location of central air
conditioning units has been discouraged by the Landmarks Board because of their size
and noise production. The latest generation of split systems are discretely sized and
considerably quieter than those available ten years ago. In addition, with a relatively
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high seasonal energy efficiency rating (SEER) of 19, the United States Department of
Energy recommends these systems as an alternative to less-energy efficient window
units.
FINDINGS
Subject to the conditions stated in the June 6, 2018 staff memorandum, staff recommends
that the Landmarks Board approve the application and adopt the following findings:
Providing the listed conditions are met, this application will be consistent with the
purposes and standards of the Historic Preservation Ordinance (Chapter 9-11, B.R.C.
1981) in that:
1. The proposed installation will not adversely affect the special character or
special historic, architectural, or aesthetic interest or value of the historic
district. Sec. 9-11-18(b)(2), B.R.C. 1981.
2. The proposed new construction will generally comply with the Energy
Conservation Measures section of the Chautauqua Park Historic District Design
Guidelines; Section 8.2 “Energy Efficiency” and Section 8.3 “Mechanical and
Utility Facilities” of the General Design Guidelines; and Section 9-11-18(b) & (c),
B.R.C. 1981.
ATTACHMENTS:
A: Applicant Materials
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Attachment A: Applicant Materials
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