Museum Windows S.Waite memo.pdf10 October 2017
Mr. Leif Bjorback
City of Edmonds Building Official
City of Edmonds
121 5th Avenue North
Edmonds, WA 98020
RE: Replacement window and skylight proposal
City of Edmonds' Carnegie Library Museum, 118 51h Ave. North
Dear Mr. Bjorback,
The Edmonds Historic Preservation Commission, as codified by ordinance, is to
serve as the city's primary resource in historic planning and preservation. We would
like to state our support for the City's proposed window replacement program as
discussed below.
Historical background:
The brick masonry Carnegie Library was opened in 1911 and was placed on the
National Register of Historic Places in 1973. It was also placed on the Edmonds
Historic Register in 2004. It possesses numerous qualifying attributes, such its
significant association with Edmonds' history and cultural heritage, as well as its
embodiment of distinctive architectural characteristics. The historic windows were
recognized as an essential component of the building's extraordinary architectural
design in period, proportion and style.
Previous alteration work:
In the 1990's, new windows replaced the original double hung, single pane wood
sash units. Those replacement windows soon became problematic; they were not
operable for ventilation; they were of metal construction and did not contain a
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thermal break for energy efficiency. They also presented a false historic narrative in
their detail.
Recent efforts to convert an existing window to an opening function failed due to its
structural deficiencies; any repairs to the sash and muntins are technically
infeasible due to feeble joinery.
Proposed scope of work:
The Carnegie Library ("Edmonds Museum") is still owned by the city; it is proposed
that all windows be replaced with historically authentic units. Reinstatement of the
thin distinctive profile of the original double -hung units is possible with single pane
glazing, but is not with double glazed insulated panes. Furthermore, the weight of
double hung insulated glazed units of this size (4'-2" x 9'-4") has proven to be a
maintenance issue in other installations, as well as immanent failure of the rail and
sash joinery.
Also proposed is the replacement of the existing single pane metal -framed roof
skylight. It will contain insulated glazing and comply with the current energy code;
its shape and proportions will be similar to the original.
Energy code issues:
The Washington State Energy Code (WSEC) requires that replacement fenestration
products (e.g. windows) in any building meet U-factor and SHGC criteria; single
glazed windows would not meet that specific requirement.
However, the WSEC does recognize the value of retaining and preserving historic
buildings by stating, T501.6 Historic buildings. The building official may modify
the specific requirements of this code for historic buildings and require alternate
provisions which will result in a reasonable degree of energy efficiency".
An alternate provision is the proposed replacement of the existing inefficient metal
frame windows (containing no thermal break); the new units will be of a more
energy efficient wood sash and frame. Additionally, those new units will have
modern gaskets to address the existing air leakage. Furthermore, the insulated
glazed skylight supports the code's intent of a more energy efficient building than
what currently exists.
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Window research, repairs and replacement authenticity:
Prior to a window field inspection, the original construction specifications were
consulted. 1 On September 29th 2017 an inspection of the northeast window on the
east lobby wall was performed 2 (appendix "A"). During that inspection, the interior
sash stop was removed: the operable window components such as sash pockets,
pulley stiles, and cast iron weights were still in place. In all likelihood these will
remain; however, worn components will either be cleaned, repaired or replaced
with similar that are still manufactured. Various millworks, such as dados, parting
strips, blind stops were consistent with the specifications and will be repaired or
reinstated.
The above observations will be the basis for window replacement and is consistent
with the Secretary of the Interior's Standards for Rehabilitation ("when a historic
feature is missing or is too deteriorated to repair, the new feature shall match the
old in design color, texture and other visual qualities and, where possible,
materials".) 3
Should you have questions, I would be most pleased to discuss with you at your
convenience.
Sincerely,
Steve Waite
Position 1
Edmonds Historic Preservation Commission
'Specifications of Labor and Material Required in Erection and Completion of Public
Library Building to be Erected at Edmonds. Washington. Designed by H.B.Ward
Seattle, Wash. No date. Source: Edmonds Historical Museum.
2 Present were: Thom Sullivan, City of Edmonds Facilities Manager; Dan Housler,
City of Edmonds Maintenance Tech; Katie Kelly, Edmonds Museum Director; Mike
Kunnen, Seattle Historic Window Company.
3 Interpreting The Secretary of the Interior's Standards for Rehabilitation. ITS
Number 23. National Park Service, Technical Preservation Services.
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Appendix 'A'
September 29th. 2017 meeting notes recorded by Mike Kunnen:
1. The 2 1/2" sash pulleys noted in the Specifications were still in place in the
inspection window and are most likely present in the other windows.
2. Sash pocket covers were observed in the pulley stiles.
3. The original cast iron weights were observed in the inspection window and are
most likely present in the other windows.
4. The paint line at the top of the lower sash was approximately 53" from head
jamb, which is consistent with period photos that show a 50/50 division of the
upper and lower sash.
S. The 1/2 dado in the pulley stile was observed which is consistent with the
Specifications which noted the use of a " 1/2" x 7/8" parting strip".
6. The distance between the exterior blind stop and the paint line at the edge of the
sash stop was 4" which is consistent with a 1/2" parting strip and the combined
thickness of two 1 3/4" sash which would be 3 1/2".
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