DECISION REQUEST REPORT
Governance & Priorities Standing Committee
____________________________________________________________
DATE:
October 29, 2012
PREPARED BY:
Ian Scott, Senior Planner
ENDORSED BY: Deb Day, Director, Planning & Development
SUBJECT:
Zoning Regulation Bylaw Improvement Project – Phase 2
Perceived Building Height on Sloped Sites
Executive Summary
The purpose of this report is to provide Council with preliminary information, analysis and
recommendations regarding the perception of building height on sloped sites in low density
residential zones. This is the last of four reports on a series of topics that relate to grade,
landscaping and perception of building height on sloped sites.
On sloped sites, houses can appear over-height when viewed from the downslope side of a
building. There are zoning strategies that could be applied to address this issue. However, to a
considerable extent, actions taken during Phase 1 of the Zoning Regulation Bylaw Improvement
Project related to roof-top decks, basement ceiling heights and cellars, as well as the
amendments proposed related to retaining walls and hard-surfaced landscaping, will serve to
limit or soften the impacts of these downward slope building facades.
Any amendments in this regard to the Zoning Regulation Bylaw would be a large change, may
have substantial impacts on the development rights of property owners and may limit the
architectural style options. Further study of a regulation of this type is recommended and would
require an adjustment to staff’s current work program to accommodate it in the near future.
Recommendation
That Council receive the report Zoning Regulation Bylaw Improvement Project – Phase 2:
Perceived Building Height on Sloped Sites for information and not proceed with any
amendments to the Zoning Regulation Bylaw at this time.
Respectfully submitted,
Ian Scott
Senior Planner
Development Services
Deb Day
Director
Planning and Development
Peter Sparanese
General Manager
Operations
Report accepted and recommended by the City Manager:______________________________
Gail Stephens
IS:aw
W:\Zoning Bylaw\Zoning Bylaw Review\Phase 2\Reports\GPC Report 4 - Perceived building height - October 29.doc
Governance and Priorities Standing
Zoning Regulation Bylaw Improvement Project – Phase 2:
Perceived Building Height on Sloped Sites
1.
October 29, 2012
Page 2 of 7
Purpose
The purpose of this report is to provide Council with information, analysis and recommendations
regarding the perceived height of buildings on sloping sites. This is the fourth of four reports on
a series of topics that relate to grade, landscaping and perception of building height on sloped
sites.
2.
Background
This report addresses issues related to the Phase 2 Zoning Regulation Bylaw Improvement
Project focused on “Grade Calculations in Low Density Residential Areas”. Through this work, a
number of interrelated issues, including issues pertaining to the construction of retaining walls
and associated alterations of lot topography, were identified.
As illustrated below, the height of buildings on sloped lots can look taller, even up to a full
storey, from the down-slope side of the lot as compared to the up-slope side. The massing of
these buildings, as perceived from the down-slope side, has been cited by some as negative. In
comparison, the basement level of a home on a flatter site will appear partially below grade from
all sides of the building, resulting in less imposing building massing.
3.0
Issues
The issues associated with the perceived building height on sloped lots include:
•
•
impact of Phase 1 Zoning Regulation Bylaw (ZRB) amendments and
recommended Phase 2 amendments
options for reducing the perceived height of buildings on sloped sites.
Governance and Priorities Standing
Zoning Regulation Bylaw Improvement Project – Phase 2:
Perceived Building Height on Sloped Sites
October 29, 2012
Page 3 of 7
4.0
Analysis
4.1
Impact of Phase 1 Zoning Regulation Bylaw Amendments and Recommended
Phase 2 Amendments
As illustrated in Figure 1, using average grade to determine maximum permitted building height
can result in buildings on sloped sites where the basement level is fully visible, resulting in a
building that appears to have an additional storey from a down-slope vantage point. As
discussed in the staff report on Grade Calculations in Low Density Residential Areas, using an
average grade methodology is consistent with best-practices and the existing ZRB definition
provides no incentive to alter natural grade such that a taller building may be constructed.
Figure 1: Illustration of how a building on a sloped site may appear as three storeys and “overheight”.
Amendments to the ZRB completed as part of Phase 1 of the Zoning Regulation Bylaw
Improvement Project have had a positive impact on the perceived height of a sloped-site
building, including:
•
•
•
prohibition on roof-top decks such that roofline railings do not further emphasize
building height and massing
an amended basement definition clarifying that the ceiling of a basement can be
no higher than 1.2 m above grade, which requires the building to be further below
grade and de-emphasizes the building massing
elimination of the option to construct cellars as bonus floor area, which results in
overall smaller-sized buildings.
If the recommended ZRB amendments contained in the companion reports related to retaining
walls and hard-surfaced landscaping are implemented, this issue will be mitigated in the
following ways:
•
•
a maximum retaining wall height limit of 1.22 m (4 ft) and a maximum slope of 1
to 1.5 for tiered retaining walls will de-emphasize the extent of overall lot
alterations
the size of hardscaped patios, walkways and stairs in required setback areas will
be reduced with amended “site coverage” and “landscaping” definitions, thereby
reducing the overall perceived height and massing of buildings
Governance and Priorities Standing
Zoning Regulation Bylaw Improvement Project – Phase 2:
Perceived Building Height on Sloped Sites
•
4.2
October 29, 2012
Page 4 of 7
the planting of more vegetation will help to soften sites and de-emphasize the
massing of new buildings with the requirement for minimum soft landscaping
requirements.
Options for Reducing the Perceived Height of Buildings on Sloped Sites
As illustrated in Figure 2 (a graphic from the City of Calgary’s Slope Adaptive Development
Policy and Guidelines), a principle that is sometimes advocated is for buildings to step down
with the slope for a more sensitive approach to sloped-lot development that, in part, would
minimize perception of height. However, this style of home construction generally has not been
occurring with recent sloped-lot development in Victoria, despite the fact this style of building
could meet the existing ZRB regulations.
Figure 2: Illustration of the City of Calgary’s preferred approach to building on sloped sites,
from Slope Adaptive Development Policy and Guidelines.
Three-storey building faces are not a new phenomenon in the architectural history of Victoria.
Within the Rockland Neighbourhood with large lots and large, old homes, there are a number of
examples. Large buildings with three-storey faces are also found throughout other Victoria
neighbourhoods. As compared to recent examples, these older buildings typically have:
•
•
•
•
less glazing (a more balanced proportion of “solids” to “voids”)
lower levels without garage doors
few and small windows on the lower level, and
sloped upper-storey roofs.
These design elements collectively reduce perceived massing of buildings.
Governance and Priorities Standing
Zoning Regulation Bylaw Improvement Project – Phase 2:
Perceived Building Height on Sloped Sites
October 29, 2012
Page 5 of 7
A number of factors have resulted in a more pronounced visual impact of three-storey building
faces in the recent years, including:
•
•
•
A garage within the principal dwelling. This is particularly true for narrower lots,
which are common for infill development sites.
A growing popularity of modern building forms with angular shapes, wide
framing, significant extents of glazing, limited ornamentation and increased use
of concrete, which can emphasize the massing and height of building depending
on the design composition.
Maximum driveway-slope regulations, which generally do not allow for sloping
driveways to access garages or parking areas located more than 0.5 m above or
below the street elevation. This leads to excavation of sites to provide level
access to basement-level garages.
The perceived visual impact of three-storey building faces may be related to building design.
Development Permit Area legislation does not permit the local government to control design in
low density residential zones. However, there may be some options through the City’s zoning
powers. Among the issues tackled in the four reports being presented to Council related to
grade calculations, this issue could have the most significant impacts on property owners and
the overall architectural style of new buildings. A more thorough review and detailed analysis is
required. To dedicate the required staff resources to this issue would require Council to make
this a priority project and identify which of the other projects are no longer a priority.
Through the process of developing recommended solutions related to grade calculations,
retaining walls and landscaping, staff also conducted some preliminary analysis of the zoning
strategies that could be applied to the issue of perceived building height on sloped sites. The
staff recommendation is that further analysis and work related to the perception of building
height be delayed to future work programs. The preliminary analysis is included below for
Council reference.
Zoning Strategy: Do not use average grade to determine building height
If average grade is not used to regulate building height, then a maximum building height line
would be established parallel to the slope of the lot. However, this would be a significant
regulatory change and is not sensitive to the fact that the floor of buildings are flat and most
people do not want a building with a myriad of different levels and stairs. This approach would
reduce the size of buildings, but also make it much more difficult to build on sloped lots. This
approach may also result in more rock and soil removal in an effort to get buildings further sunk
into the ground. As this approach also requires considering the elevation of the land under a
building, rather than only at the edge of the building where the elevation of the land can readily
be observed and measured, there would be significant administrative challenges to this
approach. This zoning strategy is not used in any municipality that staff is aware of and is not
likely a viable solution.
Zoning Strategy: Implement a one-and-a-half storey height limit in the R1-B and R1-S2 Zones
Buildings perceived to have three-storeys are not as easily achieved in the R1-G Zone or R-2
Zone as only 1.5 storeys are permitted above a basement. This regulation was added to the
R-2 Zone in 1997 in an effort to ensure that newly-constructed duplexes would fit better into
existing, Traditional Residential neighbourhoods. This same strategy was later applied to the
R1-G Zone in 2002, as a result of recommendations in the Gonzales Community
Governance and Priorities Standing
Zoning Regulation Bylaw Improvement Project – Phase 2:
Perceived Building Height on Sloped Sites
October 29, 2012
Page 6 of 7
Neighbourhood Plan, which sought to improve the fit of new houses with the size and character
of existing houses in the neighbourhood.
However, it is still possible to build three-storey building faces even within the R1-G Zone and
R-2 Zone. This occurs because of design choices related to location of floor area for the halfstorey (which can be up to 70% of the floor area of the ground floor area) or where vaulted
lower-floor spaces are also included in the design. Thus, introducing a 1.5 storey height limit for
dwellings with basements in the R1-B Zone and R1-S2 Zone may reduce, but not eliminate, the
construction of buildings with three-storey building faces within these zones. Some
municipalities have chosen to double-count floor area where vaulted space exceeds a specified
maximum (e.g. 4.5 m [15 ft]). This essentially allocates floor space to the floor above that is
occupied by the vaulted open space. Such a ZRB amendment along with a 1.5 storey limit
would further reduce, but not eliminate completely, three-storey building faces.
Within the R1-A Zone, buildings may be as much as two-and-a-half storeys. On sloped lots in
this zone, a building with a three-storey building face would still be possible unless a similar
height limit were implemented, as in the R1-G Zone and the R-2 Zone. Given the character of
buildings in Rockland which feature many homes with three-storey or taller building faces, such
a restriction may not be appropriate.
Zoning Strategy 3: Require an upper storey step-back
To address the issue of the perceived height of buildings on sloping low-density sites, the
District of Saanich has an upper-storey step-back requirement. As illustrated in Figure 3, this
approach defines an area into which a building cannot project, as measured from the finished
grade of the down-slope building face. In short, for a building that is close to the maximum
permitted building height on the down-slope side of the building, the upper storey must step
back a minimum of 5 m from down-slope building face. This step-back requirement ensures
that the upper storey is stepped back and the lowest part the building on a sloped lot presents a
less imposing building mass.
Figure 3 – Illustration of how upper storey step-back regulations are applied to a building.
Governance and Priorities Standing
Zoning Regulation Bylaw Improvement Project – Phase 2:
Perceived Building Height on Sloped Sites
October 29, 2012
Page 7 of 7
Zoning Strategy 4: Modify off-street parking and driveway slope requirements
On a lot that rises up above the elevation of the street, minimum driveway slope grades and
restrictions on front-yard parking mean that a garage is typically built into the basement level of
the building and often two full storeys are constructed above. Amending the ZRB to restrict
where a garage may be sited within a building, permitting front-yard parking in all low-density
residential zones and permitting steeper driveways are all options that may lead to garages
being a less dominant element of some sloped-site homes. However, consideration of these
options must be balanced with all functional requirements for vehicular access/egress and
storage as well as neighbourhood character considerations.
4.0
Options
Option 1 (staff recommendation)
That Council receive the report Zoning Regulation Bylaw Improvement Project – Phase 2:
Perceived Building Height on Sloped Sites for information and not proceed with any
amendments to Zoning Regulation Bylaw at this time.
Option 2
That Council direct staff to further study the issue of perceived building height on sloping lots in
low-density residential zones and that Council identify which priority project this work should
replace.
5.0
Conclusion
This report identifies that there may be zoning strategies that could limit the perceived height of
buildings on sloped sites in low-density residential zones. However, as both the Phase 1 ZRB
amendments and recommended ZRB amendments related to retaining walls and hard-surfaced
landscaping will serve to limit the apparent size and visual impact of new construction, staff is
recommending that there be no further ZRB amendments considered at this time. The research
and analysis undertaken by staff to produce this report have confirmed that more detailed
analysis of the options and implications of any changes, as well as community and industry
consultation, would be a significant work program item. Completing this work would require
Council to identify a priority project that should be replaced. It is recommended that this project
not be undertaken at this time and instead allow the proposed ZRB changes to be put in place
and new development be guided by these new rules.
6.0
Recommendation
That Council receive the report Zoning Regulation Bylaw Improvement Project – Phase 2:
Perceived Building Height on Sloped Sites for information and not proceed with any
amendments to Zoning Regulation Bylaw at this time.