July 6, 1998
CORPORATE SERVICES COMMITTEE
SPECIAL COMMITTEE TO REVIEW THE FINAL REPORT OF THE
TRANSITION TEAM
The Sub-Committee recommends the endorsement of the joint report (June 26, 1998) from
Commissioners of Corporate Services and Works and Emergency Services respecting
"Window Improvement Project - Toronto City Hall".
Background:
The Sub-Committee - Relocation of All Members of Council to City Hall on June 29, 1998,
had before it the following joint report (June 26, 1998) from the Commissioners of
Corporate Services and Works and Emergency Services respecting "Window Improvement
Project - Toronto City Hall".
The Sub-Committee's recommendation is noted above.
Interim Clerk
Sub-Committee
Relocation of All Members
of Council to City Hall
cc:Commissioner, Corporate Services
Director, Interim Lead, Real Estate Division
June 26, 1998
To:Sub-Committee for the Relocation of All Members of Council to City Hall
Toronto Atmospheric Fund
From:Margaret Rodrigues, Commissioner, Corporate Services and
Barry H. Gutteridge, Commissioner, Works and Emergency Services
Subject:Window Improvement Project- Toronto City Hall
Purpose:
To report on the request to replace or improve Toronto City Hall windows with modern
technology that would solve the problems of:
1.Unacceptably high levels of heat loss which increase building operating costs;
2.Condensation buildup which causes mould/mildew and deteriorated air quality;
3.Cold air infiltration which makes the building drafty;
4.Noise penetration emanating from events on Nathan Phillips Square; and
5. Low relative humidity levels which cause occupant discomfort and complaints of dry air
and static electricity.
The window replacement program would be done in stages to coincide with phased
renovations of City Hall beginning with the first, second and other selected floors as part of
the Phase 1 renovations and continuing with each of the towers in subsequent phases.
Funding Sources, Financial Implications and Impact Statement:
Preliminary discussions have taken place between the Toronto Atmospheric Fund and City
Staff
for the provision of a repayable loan to the City to cover all costs related to this window
improvement project. The actual financial implications and impacts (including the
magnitude of carbon dioxide emission savings) will be determined after detailed technical
building and energy use simulations are conducted. Project costs will be recovered from
energy savings.
Recommendations:
It is recommended that:
(1) the Commissioner of Corporate Services issue a Request for Proposal call for the phased
improvement of all City Hall windows as outlined in this report;
(2) the Toronto Atmospheric Fund (TAF) accept this report in consideration of the City's
interest in securing a repayable loan from the TAF to cover all costs associated with the
window replacement proposal selected by the City;
(3)this report be sent to the Toronto Historical Board for information; and
(4) the appropriate City Officials be authorized and directed to take the necessary action to
give effect thereto.
Council Reference/Background/History:
The Relocation Sub-Committee and Special Committee adopted a motion that I report, in
consultation with the Energy Efficiency Office of Works and Emergency Services on a
program to replace all City Hall windows with more energy efficient windows. This window
replacement program would be undertaken in stages to coincide with the phased renovation
of City Hall.
Comments and/or Discussion and/or Justification:
GENERAL
Windows serve several important functions in the building envelope, including;
1.Contribute to outdoor visual communication and profile;
2.Control of solar radiation for light and heat;
3.Assist with the occurrence of natural ventilation;
4. Contribute to the structural integrity, safety, occupant comfort and security of the
building; and
5. Provide insulation of indoor environment from outdoor elements such as weather, dust,
and noise.
Windows are the weak link in the building's thermal envelope. Traditional double pane
insulating glass conducts heat 10 to 20 times faster than typical insulated walls. Investment
in window replacements for strictly energy efficiency reasons is usually not economically
feasible as the energy and cost savings are usually low resulting in a payback that cannot be
justified in dollar savings. Windows replacement or improvement should be considered a
long term capital expenditure as part of a comprehensive building renewal program. The
decision to improve or replace windows is normally not based solely on energy efficiency.
Other factors such as asset value, occupant comfort, architectural integrity and safety must
be considered in any selection process. The existing single glazed windows at City Hall
contribute or exacerbate the problems of occupant comfort complaints, increased operating
costs, questionable air quality and building deterioration. Any window replacement or
improvement program should carefully considered all of the existing problems and possible
solutions as well as the economics and qualitative benefits.
Toronto City Hall was designated as an historical building in the late 1980's and as such any
alteration or modification to the building facade would require consultation with the Toronto
Historical Board. Therefore I am recommending that this report be sent to the Toronto
Historical Board for information and consultation.
In 1992, reflective window film was installed in the tower and podium windows to
counteract increasing problems with rising interior temperatures in the cooling season,
particularly the upper floors of the East Tower. This was due to increased building
occupancy, increased internal heat gains from office equipment such as desktop computers,
laser printers and photocopiers, and an extended air conditioning season due to unusually
high temperatures.
WINDOW IMPROVEMENT OPTIONS
Consultations with the Energy Efficiency Office of Works and Emergency Services have
led to two potential approaches to arriving at a solution to the window performance
problems being encountered.
Option A -Remove and replace existing windows with energy efficient technologically
advanced windows; or,
Option B - Leave existing single glazed windows intact and install a second
technologically advanced glazing on the interior of the window frame.
The dollar savings and project costs provided by the Energy Efficiency Office for each of
the two options are the best estimates available using certain assumptions. Before a project
of this magnitude is carried out, in-depth analysis and computer modelling is necessary to
ensure accuracy of the projected savings.
The selection criteria for the replacement or improvement of the windows for this project
are based on the following problems:
1. Unacceptably high levels of heat loss which increase building operating costs;
2. Condensation buildup which causes mould/mildew and deteriorated air quality;
3. Cold air infiltration which makes the building drafty;
4. Noise penetration emanating from events on Nathan Phillips Square;
5. Low relative humidity levels which cause occupant discomfort and complaints of dry air
and static electricity; and,
6. Cost- The technology must be cost-effective with a payback not exceeding 25 years for
the incremental cost of the project.
OPTION A - HIGH EFFICIENCY WINDOWS
DESCRIPTION
This technology consists of a glazing unit with two layers of glass and two low-E films
suspended in a highly insulated aluminum frame. The combination of a high performance
glazing unit and insulated frame greatly improves the thermal performance of the window by
preventing thermal bridging at the window frame. This technology effectively seals out the
elements, eliminates drafts and promotes a near constant indoor glass temperature. It
provides excellent noise attenuation and meets or exceeds all six standard selection criteria
previously outlined.
COST
The cost for turnkey installation of this technology ranges between $500 and $600 per m2 of
window. This option includes the installation of new windows from the building exterior.
Materials would be moved to appropriate floors via a material lift located on the exterior of
the building. The work activities within the building interior would be minimal however
occupants would be relocated temporarily as windows are being removed and replaced from
the exterior of the building. The cost includes the supply and installation of new windows
and the removal and recycling of the existing windows, exclusive of taxes. This option
would clearly be the highest cost in absolute terms.
Total glazed area for the entire City Hall complex is 9,000 m2 @ $550 per m2
East & West Towers - 5,600 m2 $3,080,000
Council Chamber- 1,100 m2$ 605,000
Ground and Second Floors - 2,300 m2$1,265,000
$4,950,000 + GST
SAVINGS
Preliminary analysis indicates annual savings of $ 200,000 in operating costs.
The associated savings are:
1. $ 150,000 in heating costs; and,
2. $ 50,000 in cooling costs.
The total savings of $ 200,000 in operating costs yield a simple payback of 25 years.
BENEFITS
High efficiency window replacement will provide the City of Toronto numerous benefits
which includes:
- Reduced cooling loads. Improved shading coefficients will greatly reduce the solar
loading on the building.
- Reduced heating loads. Lower u-value windows will provide a significant improvement
over the non-thermally broken single glazed system presently installed in the building.
The u-value of the existing windows is extremely high, and there is great heat loss
through these windows.
- The reduction in heating/cooling loads will greatly improve occupant thermal comfort.
Glass surface temperatures will be much closer to room temperature maintaining a near
symmetrical mean radiant temperature.
- High sound transmission glass will help prevent the unwanted noise from entering the
buildings.
- Unwanted air infiltration through the window system will be eliminated.
- Virtually 100% of the Ultra-Violet light spectrum is blocked, thus preventing damage to
UV sensitive finishes.
OPTION B - INTERIOR STORM WINDOWS
DESCRIPTION
An interior storm window improves the efficiency of a window by functioning as an
additional transparent seal and barrier. These windows are designed to be easily attachable to
the inside of an existing window using magnetic strips to hold the window in place. This
allows for simple installation and removal. Interior storm windows have been used
successfully in retrofits of historical buildings as alteration or modification of the building
facade is not desirable. This option would require the installation of finished removable
interior magnetic windows to be custom made to fit around the perimeter of each window,
covering both the metal frame and glazed areas. A virtual air tight seal would be attained by
the use of high powered adhesive sealants between the existing and new frames as well as by
the magnetic seal between the PVC subframe and the magnetic window system frame.
The magnetic interior storm windows would complement the prior investment in window
film and would in fact extend the life of the window film by providing protection against
scratches and condensation.
COST
This option can be installed in phases with minimal extra costs as the construction of a
swing stage or monorail system is not required.
East & West Towers (not stairs)$745,000
Council Chamber & Elevators$148,000
Ground and Second Floors$317,000
$1,210,000 + GST
SAVINGS
The associated projected savings are:
1. $ 60,000 in heating costs; and,
2. $ 40,000 in cooling costs.
The total savings of $ 100,000 in operating costs yield a simple payback of 12 years.
BENEFITS
The qualitative benefits that would be obtained after the installation of the Option B -
interior storm window include:
1. Improved employee health and comfort - The increased relative humidity levels resulting
from the installation should abate the constant employee complaints about dry air, static
electricity etc.
2. Enhance building environment - The increased relative humidity levels will enhance the
building environment.
3. Maintain Historical Integrity - An interior storm window does not alter or modify the
existing building facade and preserves the historic City hall building facade.
4. Reduce Noise Levels - An interior storm window would reduce noise penetrating into
the towers from the activities on Nathan Phillips Square.
5. Minimal Staff Disruption - Contrary to conventional window installation which involves
the removal of existing windows potentially during business hours, the technology involved
with Option B (Interior Storm Windows) can be installed from the interior of the building
during off-hours (evening & weekends)
A comparison of the two window retrofit/improvement options is contained in Table # 1.
TABLE # 1
Table #2 below shows the summary of savings cost and simple payback for the two
technologies discussed in this report.
A third option to be considered involves the replacement of the existing windows with
double glazed gas filled technology. This option would be similar to Option A above, but
would cost the City considerable less funds. It is reasonable to expect that window suppliers
will be able to meet or exceed the selection criteria outlined in this report.
As mentioned previously, the dollar savings and project costs provided by the Energy
Efficiency Office above are the best estimates available using certain assumptions. Before a
project of this magnitude is carried out, in-depth analysis and computer modelling is
necessary to obtain the best estimates and to ensure accuracy of the projected savings.
The quantitative benefits i.e energy and dollar savings indicate a significantly shorter simple
payback for the installation of the Option B- Interior Storm Windows versus Option A- High
Efficiency Windows.
In consideration of the above, I am recommending that the Commissioner of Corporate
Services issue a Request for Proposal call for the improvement of all City Hall windows.
This window replacement program would be undertaken in stages to coincide with phased
renovations of City Hall beginning with the first, second and other selected floors as part of
the Phase 1 renovations and each of the towers in subsequent phases. I am also
recommending that the Toronto Atmospheric Fund (TAF) accept this report in consideration
of the City's interest in securing a repayable loan from the TAF to cover all costs associated
with the window replacement proposal selected by the City, with repayment from future
savings.
Margaret RodriguesBarry H. Gutteridge
