POLICY REPORT
URBAN STRUCTURE
Date: November 24, 1999
Authors/Local: EFiss/7929 DWatts/6051
RTS No. 0082
CC File No. 2603Council: December 14, 1999
TO:
Vancouver City Council
FROM:
Director of Current Planning in consultation with the City Building Inspector
SUBJECT:
Barrett Commission of Inquiry into the Quality of Condominium Construction in British Columbia Recommendations for Municipal Review of Zoning and Development By-laws
RECOMMENDATION
The Director of Planning recommends that Options A and B be referred to Public Hearing:
A. THAT the Director of Planning be instructed to make application to amend the applicable sections of the Zoning and Development By-law No. 3575, Official Development Plans (ODPs), and CD-1 By-laws, generally in accordance with Appendix A, to provide a Floor Space Ratio exclusion that removes disincentives for improved exterior wall construction resulting in thicker walls, in response to the recommendations of the Barrett Commission of Enquiry into Condominium Construction in British Columbia;
FURTHER THAT the Director of Legal Services be instructed to prepare the necessary by-laws;
AND FURTHER THAT the application and by-laws be referred to a Public Hearing.
B. THAT should Council, at Public Hearing, not approve the amendment outlined in A, the Director of Planning be instructed to continue to measure floor area to include the entire exterior wall, as is currently required, with no exclusions for improved wall construction to control building leaks.
GENERAL MANAGERS COMMENTS
The General Manager of Community Services RECOMMENDS that Options A and B be referred to Public Hearing for consideration, noting that Option B represents the status quo. The consequences of both options will be fully discussed at the Public Hearing.
COUNCIL POLICY
On December 7, 1995, Council adopted Part 5 of the 1995 National Building Code (NBC) as part of the Vancouver Building By-law to control building leaks with revisions to suit the specific conditions in Vancouver.
PURPOSE AND SUMMARY
This report is in response to Councils request for a report back on the Barrett Commissions recommendations on Floor Space Ratio (FSR) exclusions to provide construction incentives to control building envelope leaks.
The Vancouver Building By-law has already adopted measures to control leaky buildings, including requirements for rain-screen assemblies and the involvement of Building Envelope Specialists in the review of the design and construction of wall assemblies.
This report addresses three principal areas of concern raised by the Barrett Commission Report: FSR measurement, balcony and walkway area exclusions, and overhangs. Of these, the issue of FSR measurement has generated the broadest level of discussion. Following staff consultations with industry advisory groups and in reviewing by-law changes proposed by other Lower Mainland municipalities, staff put forward Option A in this report, representing a consensus of opinion on an approach that removes the disincentive of FSR penalty in pursuing better building envelope design.
Option A would provide an exclusion from FSR for exterior wall thickness in excess of 152 mm (6 in.), to a maximum exclusion of 152 mm (6 in.) of additional wall thickness. The exclusion would therefore be available for wall thicknesses greater than 152 mm (6 in.) and up to 304 mm (12 in.). The typical frame wall now accepted by the City as the minimum standard is generally 152 mm (6 in.) thick. This is typical construction on the majority of current residential buildings, with an exterior finish of stucco or siding and a required 19 mm (¾ in.) air cavity, which would not benefit from the proposed FSR exclusion. This wall is only marginally thicker (by ¾ in. +/-) than the standard wall widely utilized prior to the City requiring an air cavity. The exclusion would only be achievable where better weather protection methods are used, such as additional layers of insulation or thicker exterior finish materials, such as brick masonry or concrete.
Other regulations which are used to control bulk and massing, including height, yards and setbacks would remain unchanged and would not be relaxed to accommodate this FSR exclusion. The impact on total bulk would be up to an additional 3 percent FSR; from approximately 0.04 FSR in a Multiple Family District, such as RM-4 maximum FSR 1.45), to approximately 0.10 FSR in a Commercial District, such as C-2 (maximum FSR 3.0). The impact on a 20-storey residential tower could be the equivalent of an additional FSR of 0.15 in, for example, Downtown South (maximum FSR 5.0), which would be approximately one-half of a storey. Staff does not believe that this additional bulk will significantly impact the currently accepted form and massing of development.
There are, however, administrative impacts to this proposal. The exclusion will add complexity and time to the application process. There is also the view that the construction industry should be responsible for producing a product that performs well and no special incentives should be necessary for that to happen. Therefore, staff are also putting forward Option B, which would retain the existing FSR calculation, without exclusions for exterior walls.
The other recommendations in the Barrett report concerning exterior walkways, protection by roofs of top floor balconies, and the promotion of roof overhangs have already been clarified or addressed through existing City by-laws. That is, Vancouver zoning by-laws, with respect to walkways, balconies, and roof overhangs, do not create a disincentive to the construction of buildings in terms of sound building envelope design practices.
BACKGROUND
Barrett Commissions Recommendations: On July 30, 1998, Council received a staff report outlining the content of the Barrett Commission Report and recommending a City position on various aspects of the Report as well as amendments to the Building Code. In addition, Council has requested a Report back on the following Barrett Commission recommendation:
That all municipalities review their zoning by-laws, and the calculations of FSR, with a view to promoting sound building envelope design practices. In particular, the following revision should be reviewed:
(a) FSR calculations to be taken only to the inside face of the principal structural elements of the exterior walls necessary to support the building and the walls;
(b) exclude from FSR, walk-ways and top floor balconies protected by roofs; and
(c) ways and means for promoting overhangs, which do not conflict with other municipal planning objectives.
This recommendation is in the context of a number of other Barrett Commission recommendations designed to address the leaky condo problem. These include a number of issues to be dealt with under provincial legislation through Bill 46 such as financing repairs, new home warranties, trade qualifications, and licensing as well as education and training. Other recommendations also addressed in the report include increased professional field review, review of professional letters of assurance, Building Code changes to improve current practice, and municipal liability review. Together, these recommendations represent a multi-faceted approach to solve the problem given that there are number of causes.
For a discussion of background issues including recent building code provisions and the responses of other lower Mainland municipalities, see Appendix B.
Industry Concerns: The development industry is concerned that increases in exterior wall thickness in order to construct buildings to the new standards required by the City, and as recommended by the Barrett Commission, will result in a loss of net floor area, and hence a loss in economic viability for many projects. The message which has come through clearly from consultation with various segments of the construction industry is that to ensure better walls, thicker is better.
The underlying intent of the Barrett Commission recommendation with respect to FSR calculations is that municipalities find ways of removing disincentives to building better/thicker walls. To this end, industry has expressed support for various options for excluding wall thickness from floor area, including the option presented in Option A.
The City has received requests from the AIBC to exclude floor area for various aspects of building construction including the wall assembly, overhangs, covered walk-ways, and balconies. The intent of these requests is to remove floor space limits as an influence in selecting the type of exterior wall that will offer the best performance.
DISCUSSION
Calculation of Wall Assembly FSR: Given the goals of better construction and consumer protection, City actions need to be taken in the context of the likely effectiveness of all the Barrett Commissions recommendations. If all the proposed long term actions put forward by the Commission are implemented, the overall impact on the industry will be a raised base standard of practice. In this context, it is a fundamental question as to whether Council wishes to exclusively mandate a minimum requirement through the Building Code, or to provide through FSR exclusions, compensation and encouragement to the development industry to follow better than the minimum required construction practices.
In reviewing options for potential FSR exclusions to encourage good construction, staff considered the following issues:
(a) Causal Relationship: To what extent does the current by-law regulation which includes the wall in the FSR calculation directly lead to a building design that is more prone to leak? Does the regulation preclude better design and construction or are market trends, development economics or other factors causing development decisions that only appear to be a function of the regulation?
(b) Impact on Building Form and Regulations: Amendments that introduce different requirements for measuring floor area may affect the typically anticipated form of development. Will exclusions for exterior walls result in bulkier or taller buildings? Conversely, more permissive regulations provide additional development potential for existing buildings where none may have remained before, with unintended consequences. Will we be seeing applications to add floor area and height to existing buildings?
(c) Administrative Ability: To what extent will by-law amendments add additional complexity in day-to-day administration (e.g., checking applications for compliance, information services)? Who bears the costs?
These issues were examined by staff in consultation with representatives of the construction industry as they relate to a range of options for measuring FSR.
Options for Exclusion of FSR for the Wall Assembly: The following options were reviewed by staff in consultation with industry. These discussions resulted in the option put forward to Council as Option A.
1. Barrett Commission Option
The Barrett Commission recommendation is for calculation of FSR to the inside face of the principal structural elements of the exterior walls necessary to support the building and the walls. This means only the inside wall finishing would be included in FSR (i.e. Only the interior drywall, typically 12 mm (½ in. thick)). The exterior frame walls and cladding, currently included in FSR, would be entirely excluded.
This method would remove any disincentive for builders to build various types of improved building envelopes because there would be no FSR penalty for increased wall thickness; in fact, exterior walls would be for all intent and purposes excluded. It does not, however, provide an incentive to build better walls since all walls would be exempt. (To be effective, the regulation would have to be designed to exclude the FSR only on those buildings providing more than the minimum rain-screen protection.)
This option would effectively bonus the FSR by 2 to 4 percent on many sites throughout the city without providing improved or thicker exterior walls, and consequently increase the potential building bulk as well, except on specific sites where buildings do not achieve maximum FSR because of setback and height regulations. Existing buildings, by virtue of the new calculation, would gain some new residual FSR which may lead to new additions.
Calculation of FSR to the inside face of the structural element (excluding all of the wall assembly) would lead to opportunities for additional space/bulk being added to the building through cavities, ostensibly for mechanical services for example. In addition, technical calculations will be more difficult and construction details which are normally required later on in the process, at the building permit stage, would need to be provided earlier at the development application stage.
Staff have concluded that a literal application of the Barrett Commission recommendation, while removing a disincentive to build thicker walls, would have far too many negative consequences to be workable or desirable policy.
2. Measure to the Outside Face of Structural Sheathing
A second option is to measure to the outside of the structural sheathing and exclude everything else, such as exterior cladding, cavities, and outboard insulation. This is the option which many people are interpreting the Barrett Commission to have requested. However, it differs from the Barrett Commission recommendation, by including the structural framing and sheathing in FSR calculations.
Like the Barrett recommendation, this option removes the disincentive for building superior exterior wall assemblies which result in reduced usable FSR because additional wall thickness is not counted. However, as with the Barrett recommendation, this option treats good and bad assemblies equally.
As well, there are problems with the creation of residual FSR on existing buildings. There are also parallel opportunities for abuse, by locating systems outside of the sheathing. An issue raised by this option is that a brick veneer wall (which is non-load bearing and located outside the plane of the structural sheathing) would be eligible for an exclusion but load-bearing or cast-in-place concrete construction would not (it would all be located inside the structural sheathing plane). In addition to the issues of equitable treatment of building types and adding building bulk, the biggest difficulty in using this option is the administrative difficulty, which requires a detailed technical review to identify and locate the outside plane of the building structure.
3. Option for Excluding Additional Wall Thickness
To address these potential inequities and to create a simple and clear method for calculating the FSR exclusion that does not rely on discretionary judgement, a modification of the second option, above, has been proposed. This option would continue to include in FSR a wall thickness comparable to the typical minimum thickness wall that can be built under todays building by-law (i.e. 152 mm (6 in.), but would provide an exclusion for walls thicker than this minimum, to a specified maximum.
The option would provide an exclusion from FSR for exterior wall thickness in excess of 152 mm (6 in.), to a maximum exclusion of 152 mm (6 in.) of additional wall thickness.
Applicants requesting this exclusion would provide a schedule of wall types, an additional submission requirement, indicating composition and thickness, and identify the linear extent of these wall types on their plans and trace overlays now required in development permit application submissions for FSR calculations. A written assessment report from an approved Building Envelope Professional would be required, stating how these wall types will improve the performance of the buildings environmental separation.
This option would permit an FSR exclusion only for walls greater than 152 mm (6 in.) thick and only for the actual wall area in excess of the 152 mm (6 in.). The maximum exclusion would be for an additional 152 mm (6 in.). A basic frame wall with a stucco finish, with a 19 mm (¾ in.) drainage cavity, as currently required by the City, would not qualify for any FSR exclusion. Only walls that go beyond this least common denominator type of wall, up to an additional 152 mm (6 in.), would be eligible for an FSR exclusion and with an approved report from a Building Envelope Professional.
Mass concrete walls would also benefit from this exclusion. This option would allow for an exclusion for a mass concrete wall composed of 203 mm (8 in.) of concrete and say 102 mm (4 in.) of interior finish and insulation, for a total of 305 mm (12 in.). This would allow for an exclusion of 152 mm (6 in.), which is similar to that afforded a 279 mm (11 in.) brick clad stud wall, i.e. counting 152 mm (6 in.) in FSR but excluding the exterior 127 mm (5 in.). Similarly, other types of wall construction, such as curtain wall, could benefit from this exclusion if they provided additional insulation or deeper recesses to protect window openings, without a loss of net floor area.
This option would remove the FSR disincentive to build thicker walls, minimize impact on established City policies concerning building bulk, and treat various methods of exterior wall construction equitably. Existing buildings could benefit from this option if upgrades to the exterior wall are contemplated, whether to repair leaky wall or to provide for an improved and thicker exterior wall.
The option is presented as Option A.
4. Maintaining the Existing FSR Calculation
The alternative to the proposal outlined above, is to maintain the status quo. The City would continue to mandate minimum standards through the Vancouver Building By-law without FSR exclusions and continue the current practice of calculating the additional wall thickness in the FSR calculation.
This option ensures that a minimum level of protection is provided for consumers through the existing building by-law regulations without adding any further requirements to be met or complexity to the development application process. There will be no increase in the overall bulk of new buildings. It will also not impact existing buildings in terms of creating extra allowable FSR. In some cases, a total building upgrade and/or additions to repair water damage may require FSR relaxations (as well as yard or setback) to accommodate the additional wall thickness.
The current VBBL regulation has impacted to a small degree achievable market floor space. However, the VBBL regulation does not guarantee or encourage better construction than the minimum requirement; additional improvements would have to be driven by the market.
The option is presented as Option B.
Upgrades to Repair Leaky Walls: To accommodate retrofits for buildings requiring repairs for leaky walls, Option A may add to overall building bulk and potentially add requirements for relaxations of setbacks. For Option B, retaining the current FSR calculation, in addition to requirements for relaxations of setbacks, a FSR relaxation may be required, either through approval by the Director of Planning, or through the Board of Variance. While both options have associated administrative costs and implications on staff processing time, Option A provides a predictable and positive response for homeowners facing extensive repairs to leaky buildings, which result in thicker walls.
PERSONNEL IMPLICATIONS
With the exception of Option B, retaining the current FSR calculation, all of the options studied involve increased staff work to varying degrees. With respect to application processing, none of the options would have sufficient impact to warrant additional staff. However, applications will take additional processing time with more information required from the applicant at an early stage. Application fees may need to be adjusted to ensure cost recovery for the additional costs associated with the additional time for reviewing area calculations and in the review of reports prepared by Building Envelope Professionals.
Should Council select Option A, staff will report back to Council within 18 months to evaluate the effectiveness of the new regulations and the impact on staff work loads, processing time, and administrative costs. An Administration Bulletin would be drafted to explain the new exclusion and how it works, along with process implications and submission requirements.
CONSULTATION
Faulty condominium construction has been the subject of intensive study by government, industry, and academic researchers for several years, in order to determine the reasons for, and the factors contributing to, this serious problem. City staff from both Planning and Permits and Licenses departments have met on various occasions during the past two years with representatives of the Architectural Institute of British Columbia (AIBC) and the Urban Development Institute (UDI) to discuss the impact of the Citys zoning and planning regulations on building design.
Several proposals put forward by City staff to remove disincentives to better building design have been reviewed by the AIBC and UDI, in addition to The Canadian Portland Cement Association, the Masonry Institute of British Columbia, and the Greater Vancouver Home Builders Association. The response to the options for excluding FSR for better exterior walls has been consistently positive for options that are non-discretionary and simple to define. The general message from industry has been that thicker walls are better walls.
The option put forward for Option A has resulted from subsequent discussions and recommendations by the UDI and AIBC. It addresses both industry concerns about simplicity and as much as possible, staff concerns about administration and equity for various construction types and for existing buildings. The liaison committees of the AIBC and the UDI have expressed support for this option.
There remains an industry concern that regulations for roof overhangs and door recesses continue to be a barrier to good building design. However, staff believe this concern is largely based on a persistent misunderstanding of the Citys regulations with regards to these policies. Staff will issue a Bulletin to explain the regulations concerning overhangs, and to provide for an interpretation of existing regulations that will allow an exclusion of floor area at entrance alcoves.
CONCLUSION
The leaky building problem is a serious concern for many Vancouver residents. It has been addressed by a variety of measures initiated by the Provincial Government and by the City.
Providing an exclusion from FSR for better walls, as with Option A, would remove a disincentive for their construction while marginally increasing building bulk. It could be used on repair work, without requiring an increase in FSR on existing buildings, or create non-conformities for parking or other regulations which are calculated on the basis of FSR. For repairs, only, the yard may be relaxed, by a maximum of 152 mm (6 in.), based on hardship. Setbacks should not be relaxed for new construction, however, as this would impact building massing.
The alternative, presented as Option B, accepts that the recent variety of measures initiated by the Provincial Government and by the City, through the Building By-law, are the appropriate means for addressing this serious problem. The trade-offs in building bulk and by-law complications for additional FSR incentives are not appropriate and, therefore, building quality should be market driven.
* * * * *
DRAFT AMENDMENTS TO ZONING AND DEVELOPMENT BY-LAW No. 3575 (INCLUDING CD-1 BY-LAWS)
All additions are shown in bold italics. Deletions are shown in strikeout.
RA-1, RS-1.RS-1S, RS-1A, RS-1B, RS-2, RS-3, RS-3A RS-4, RS-5, RS-5S, RS-6, RT-1, RT-2, RT-3, RT-4, RT-4A, RT-4N, RT-4AN, RT-5, RT-5A, RT-5N, RT-5AN, RT-6, RT-7, RT-8, RT-9, RM-2, RM-3, RM-3A, RM-4, 4M-4N, RM-5, RM-5A, RM-5B, RM-5C, RM-6, FM-1, C-1, C-2, C-2B, C-2C, C-2C1, C-3A, C-5, C-6, C-7, C-8, FC-1, MC-1, M-1, M-1A, M-1B, M-2, IC-1, IC-2, IC-3, I-1, I-2, I-3, HA-1, HA-1A, HA-2, HA-3, CD-1. FCCDD, DD, CWD, DEOD, FSD, BCPED DISTRICT SCHEDULES
Floor Space Ratio
The following shall be excluded in the computation of floor space ratio:
· areas of exterior wall, constructed after date of enactment, in excess of 152 mm (6 in.) thickness to a maximum exclusion of 152 mm (6 in.) thickness, for improved exterior wall construction as recommended in a report submitted by an Architect or Professional Engineer recognized as a Building Envelope Professional;
[amend Section 4.7.3 (Floor Space Ratio) or appropriate section for ODP By-laws and CD-1 By-laws]
DISCUSSION OF THE RECOMMENDATIONS OF THE
BARRET COMMISSION OF ENQUIRY
BACKGROUND
Recent Building Code Provisions: Building code provisions relating to leaks in buildings must be understood in the context of current building codes. The Vancouver Building By-law (VBBL), and the Provincial Building Code, are based on the National Building Code which is written strictly within the framework of occupant health and life safety issues. The issues involved in leaky buildings largely relate to durability of materials which do not become a code concern until deterioration leads to life safety concerns through decay and collapse of structural systems.
However, code language is starting to be rethought following changing public expectations. Future codes will likely deal with a broader scope of concerns, including issues like durability. In the recently issued 1998 Provincial Building Code, for example, a reference to durability of materials is made for the first time in the chapter that deals with building envelope design. This reference will now also appear in the new VBBL.
The City of Vancouver has taken a strong leadership position over the last four years in dealing with concerns about leaking buildings through building regulation:
(a) in December of 1995, the City issued a bulletin detailing explicit requirements concerning the application of External Insulating Foam Systems (EIFS);
(b) in 1996, two more bulletins were issued to outline the requirements for other cladding systems, and at Councils direction, we adopted the 1995 National Building Code Environmental Separation requirements (Part 5 of the code). With the adoption of, and modifications to Part 5, and the issuance of these bulletins we outlined explicit requirements for rain-screen assemblies, and created a role for a Building Envelope Specialist to provide more focussed professional review of building envelope assemblies;
(c) in 1998, the requirements were tightened for the Citys acceptance of Building Envelope Specialists. This was an interim procedure, while the two professional associations, the Architects Institute of BC (AIBC) and the Association of Professional Engineers and Geoscientists of BC (APEGBC) completed a program to create an accreditation process for a new professional title: Building Envelope Professional. This program, through our involvement, is now in place; and
(d) also in 1998, Council passed a by-law to increase the scope of application of Part 5 of the VBBL to include multiple-family residential buildings which had previously been only covered under the provisions of Part 9 (Housing and Small Buildings) and exempt from the application of Part 5. This by-law requires more buildings to comply with rain-screen and professional review requirements.
These changes, mandated by Council, set minimum standards to deal with public concerns regarding leaky buildings but still fit within the building by-law framework of health and life safety as they are intended to prevent the eventual decay of the building structure.
Other Municipalities: In March, 1999, the Homeowner Protection Office, established by the provincial government to regulate the residential construction industry, released a guide entitled Land Use Planning & Weather Protected Buildings. This is a guide for local municipal governments to be used in their review of land use regulations which have an impact on the quality of residential construction. Its particular focus, as in this report to Council, is with Recommendation #10 of the Barrett Commission Report, which addresses current methods of FSR calculations which have impacts on the construction of better buildings. The options which have been reviewed by staff in the preparation of this report to Council covered a similar range of alternatives as presented by the HPO guide. The cities of Vancouver, North Vancouver, and Surrey provided assistance in the preparation of the guide.
As Vancouver has taken the lead on these issues in the past, it appears that some of the other Lower Mainland municipalities are waiting to see what precedent the City sets. One exception is the City of North Vancouver where the municipality is going ahead with a policy that will exempt from FSR calculations a maximum 165 mm (6.5 in.) thickness of the exterior of any wall similar to Option A, where staff does not believe that there will be a significant change in the scale of development as a result of this change.
Also, in the City of New Westminster, where zoning regulations control the size of buildings through site coverage, and not through FSR, a yard relaxation of up to 203 mm (8 in.) will allow for thicker walls. In the City of Port Moody, FSR will be measured to the inside face of exterior walls. These decisions will have the effect of up-zoning the municipality without making a distinction between quality of assemblies. As well, these new policies are primarily address low-rise or medium rise multiple family buildings, and do not address the size or range of building types found in Vancouver. These municipalities are proceeding in this manner as they felt they needed to act quickly, and it needed to be simple enough to apply with limited staff resources.
DISCUSSION
1. Recommendation to review the method for calculating FSR, with a view to promoting sound building envelope design practices.
Calculation of FSR in the Zoning and Development By-law: Floor Space Ratio (FSR) is the figure obtained when the total gross area of all the floors of the buildings on a site is divided by the area of the site. FSR is the Citys primary means of controlling size (bulk) of developments, an issue of ongoing public concern. Building height, site coverage, and setbacks also regulate building bulk.
Currently, for the purpose of calculating FSR, floor area includes all floors, measured to the extreme outer limits of the building, with certain exclusions which may differ from zone to zone, being deducted from that total. Typical exclusions from floor area may include balconies (open and enclosed), patios and sundecks, residential storage area, amenity areas, and below grade parking and loading. FSR exclusions are intended to promote livability and good design by creating a density bonus for developments that incorporate amenity areas and other desirable features.
FSR is also used as a basis for determining a number of other requirements, including required off-street parking and loading, allowable accessory buildings and accessory use areas. Floor area calculations are also used to determine compliance with various size of use restrictions that are found throughout the Zoning and Development By-law. The Development Cost Levies (DCLs), Development Cost Charges (DCCs) and Community Amenity Contributions (CACs) are also based on floor area.
Wall Thickness and FSR: The current minimum requirements in Part 5 of the VBBL for wall cladding systems include the incorporation of a drainage cavity as part of the rain-screen system. This design adds an additional 19 mm (¾ in.) to the types of wall cladding systems commonly found on buildings experiencing water damage and to typical wall construction prior to July 1996 (the date when the new requirements came into effect). Additional recommended (but not mandated) design improvements to produce superior building envelope assemblies, such as the addition of building insulation outside the building structure, could add additional thickness to the wall assembly. (See diagrams below.)
TYPICAL EXTERIOR WALL TYPES
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A review of a range of building floor plans suggests that the floor area occupied by the exterior walls in typical existing buildings is in the range of 2 percent to 3 percent of the total floor area. For a typical 4-storey C-2 District project of approximately 4 000 m² (43,057 sq. ft.), the exterior wall accounts for approximately 100 m² (1,076 sq. ft.), which is 2.5 percent of the total building floor area. The 19 mm (¾ in.) drainage cavity, required since 1996, added approximately 10 m² (108 sq. ft.) to the floor area occupied by wall , or ¼ percent of the total building floor area. The addition of 75 mm (3 in.) of exterior insulation would occupy an additional 40 m² (430 sq. ft.) of floor area, or about 1 percent of the total, for a combined exterior wall total of 3½ percent of the total allowable building floor area.
For a typical existing 20 storey residential tower of approximately 9 300 m² (100,100 sq. ft.), with a smaller floor plate than the 4-storey C-2 development (and hence a greater percentage of perimeter), the floor area occupied by exterior wall would be approximately 325 m² (3,500 sq. ft.), or about 3½ percent of the total floor area. The 19 mm (¾ in.) drainage cavity, included in the wall, would be approximately 33 m² (355 sq. ft.), or _ percent of the total. A superior building envelope with the addition of 75 mm (3 in.) of exterior insulation uses an additional 130 m² (1,400 sq. ft.), approximately 1½ percent of the total floor area, for a combined exterior wall total of up to 5 percent of the total allowable building floor area.
High-rise construction which uses concrete wall construction, curtain wall, or masonry cavity walls may not require any additional thickness to meet the improved standards. However, there are some types of high-rise construction where, similar to low-rise construction, the cladding is installed over light gauge framing (steel studs). In these cases, improvements to the wall system may result in a thicker wall assembly.
It should be noted that thicker walls, using brick rain-screen construction, have been built on multi-family housing in Vancouver for many years and have generally had a satisfactory performance record. In recent years, masonry-clad walls have been used for many projects, especially those in discretionary approval zones, where high quality architectural finishes are required to earn discretionary floor area. Reasons for not using a brick veneer rain-screen wall are as often based on a savings in construction cost as in the potential loss in marketable floor area.
To summarize, the required drainage cavity has resulted in a potential loss of a relatively minor amount of net floor area, well below ½ percent of allowable floor area, typically less than 15 m² (160 sq. ft.) on a multi-family residential building.
Additional measures to improve the performance of the building, which result in thicker walls, would use approximately 1 to 2 percent for an additional 152 mm (6 in.) wall, of the allowable floor area, with a typical range of from 40 m² (430 sq. ft.) for four storey buildings to 130 m² (1,400 sq. ft.) on high rise developments.
2. Recommendation for FSR Exclusion of Walkways and Top Floor Balconies
The Barrett Commission recommends an FSR exclusion for both walkways and top floor balconies protected by roofs.
Prior to April 1996, the City did exclude exterior walkways from FSR calculations. This encouraged their construction and led to problems with building bulk, overshadowing and view blockage, and as the Barrett Commission noted, their open construction provides more opportunities for water penetration, and eventual leaks. Staff do not recommend excluding them, even if covered; but rather continue to discourage them altogether by including them in the FSR. This position is supported in the Guide prepared by the HPO, and is consistent with the discussion in the Barrett Commission Report concerning this recommendation.
Top-floor balconies need to be viewed separately from exterior walkways. Whereas exterior walkways are typically a cost savings or design feature, balconies are a significant, and often essential, amenity for residential developments, providing usable outdoor open space. As an important benefit, their use should not be discouraged.
Balconies, whether open or covered, are currently treated differently than exterior walkways in the Zoning and Development By-law. Balconies are currently excluded from FSR in both medium density and high-density residential development zones, to a maximum 8 percent of permitted FSR, typically, to promote their development. Balconies located at a middle storey are typically protected by a balcony stacked above. The uppermost balcony may be protected by a roof or canopy, and is similarly excluded from FSR.
While current Vancouver Zoning and Development By-laws are consistent with the Barrett recommendation in this regard, the problem of leaks associated with exposed balconies, even if roofed over, will persist. Therefore, improved building code regulations and the continuing education of the design and construction industries are required to address the problems of balconies which contribute to leaky buildings.
Roof decks differ from balconies, which are cantilevered from the building, in that they are located above enclosed floor area and are integral to the building massing. Where permitted, they are typically excluded from floor area and may have a maximum 1.2 m (4 ft.) cantilevered roof or canopy to provide weather protection at doorways. Additional enclosures for roof decks would have a significant impact on the bulk of the building, and for this reason enclosed roof decks are included in FSR.
As the current zoning regulations are intended to promote livability, amenity, and appropriate appearance of developments, no further changes are recommended. Exterior covered walkways would continue to be included in FSR, therefore discouraging their construction, but balconies would continue to be excluded from FSR, thus promoting usable outdoor open space amenities while permitting appropriate weather protection, as there is no FSR disincentive to provide top floor balcony roofs.
Staff therefore conclude that the current Zoning and Development By-law for the City of Vancouver satisfactorily address the concerns of this particular Barrett Commission Report recommendation concerning walkways and top floor balconies, and that no further revisions are required.
3. Recommendation to Promote Overhangs
The Barrett Commission recommends providing overhangs to provide additional rain protection. On September 5, 1991, the practice of including the area beneath cantilevered floor areas and eaves projecting more than 540 mm (21 in.) in the FSR was discontinued. The purpose of the inclusion had been to limit the size of eaves and volumes with cantilevered floor areas since these features had the effect of increasing the apparent bulk of buildings. Many builders remain unaware that this FSR inclusion has been discontinued for the past 8 years.
The area under eaves and overhangs is now excluded although projections into required yards are limited to 540 mm (21 in.) according to Section 10.7 of the Zoning and Development By-law. The RS-5 District Schedule allows a 1.0 m projection of eaves into the required yard provided they are a minimum of 700 mm from the side property line. This does not restrict the design of greater projections provided that the building is set back further so as not to project into the required yard beyond the regulated limit. The intent of this regulation is to provide for light and air in required yards, area for maintenance of eaves and gutters, as well as to limit the potential spread of fire to adjacent properties.
Staff believe the overhang of 540 mm (21 in.) now permitted to project into the required side yard is adequate for achieving the rain control objectives, and, there is no floor area penalty for providing this overhang. Staff recommend no further action on the part of the City is required.
One unique situation occurs at ground floor recesses for doors, which are below upper storey floor area. These exterior door recesses are currently included in FSR. The recess is often required to allow exit doors to swing outward without crossing the property line, as well as to provide weather protection at the building entry. The Director of Planning is prepared to issue an interpretive note to exclude floor area at exterior door recesses to the minimum area required for the safe operation of the exterior exit door.
Encroachments: Street-facing or other facades located adjacent to property lines, where a setback is not required are a special circumstance. In these cases, overhangs and eaves are permitted where the building is set back at its upper storey, and the overhang does not encroach beyond the property line. Legal agreements for an encroachment can be made; however, staff policy has been to not permit encroachments for cornices, copings, window sills, eaves, and bay windows on new buildings except in Historic areas (Gastown, Chinatown, Yaletown) and on renovations to existing buildings in these historic areas. Due to the potential issues of liability which encroachments may create, encroachments should only be considered where they contribute to the public benefit, such as for demountable pedestrian weather protection canopies and awnings. Setbacks at the upper stories to allow for an overhang to protect the walls from rain can be provided without creating an encroachment.
Remediation measures taken to repair and upgrade a wall situated at a property line may create an encroachment. In some cases, the zero lot-line building may have already allowed for a construction tolerance at the property line of up to a 50 mm (2 in.) to facilitate normal construction tolerances, window and lighting appurtenances, and hardware connections for envelope maintenance. In other cases, the City may be prepared to allow an encroachment of a minor nature provided an agreement pursuant to the Encroachments By-law was entered into.
Staff conclude that existing by-laws and enforcement policies are sufficient to address the promotion of overhangs as recommended by the Barrett Commission Report.
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(c) 1998 City of Vancouver