ITEM 4.1TPC
The Planning Company
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DATE:
RE:
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BACKGROUND
3601 Thurston Avenue
Anoka, MN 55303
763.231.5840
TPC@PlanningCo.com
Otsego Planning Commission
D. Daniel Licht, AICP
14 February 2019
Otsego — Zoning Ordinance; Residential Development Standards
101.01
ITEM 4-1
The City Council has directed that the Planning Commission review residential development
standards with regards to fire resistance. Between 2015 and 2018, there have been 20 fire
incidents involving residential properties.
The City Council has requested that the Planning Commission consider possible changes to
setback requirements or exterior material standards, particularly in zoning districts within the
East and West Sewer Districts that allows for a more -dense suburban development pattern.
The Planning Commission will have an initial discussion of this issue at their meeting on
Tuesday, 19 February 2019 at 7:00 PM.
Exhibits:
■ 17190 59th Street map
■ 12444 76th Street map
■ 7278 Martin Farms Avenue map
■ 7421 Queens Avenue map
1
ANALYSIS
Zoning Districts. The following zoning districts allow for development of residential dwellings:
District
Allowed
Dwellings
Min. SF
Lot Area
Min. SF
Lot Width
Min SF
Lot Depth
Min.
Interior
Side Yard
Setback
Min.
Rear
Yard
Setback
Rural
Al
SF
1.0ac.
150ft.
150ft.
loft.
50ft.
A2
SF
1.0ac.
150ft.
150ft.
loft.
Soft.
RC
SF
1.0ac.
150ft.
150ft.
15ft.
Soft.
R1
SF
1.0ac.
200ft.
150ft.
loft.
Soft.
R2
SF
2.5ac.
150ft.
150ft.
loft.
Soft.
R3
SF
1.0ac.
150ft.
150ft.
loft.
50ft.
Urban
R4A
SF
18,OOOsf.
Soft.
150ft.
loft.
20ft.
R4
SF
12,OOOsf.
75ft.
1o0ft.
loft.
20ft.
R5
SF, TF
9,o00sf.
60ft.
1o0ft.
7ft.
20ft.
R6
SF, TF, TH
9,o00sf.
60ft.
1o0ft.
7ft.
20ft.
R7
TF, TH, M F
NA
NA
NA
loft.
20ft.
NOTES:
SF = Single family
TF = Two family
TH = Townhouse
MF = Multiple family
The lot requirements and setbacks for rural district lots are such that homes tend to be much
more separated. The minimum lot area needed to accommodate an on-site septic system is
the primary factor as house sizes are not typically in proportion to the building envelope
compared to an urban lot. The lot requirements for the R4 District have been established to
not only to allow for current residential development within the sewer districts, but anticipate
potential rezoning and subdivision of rural service lots should sewer utilities be extended for
service. As such, an Al, A2, RC, R1, R2, or R3 District lot may be subdivided into two lots
illustrating the extent of separation between homes on such lots today.
The R4 District is considered to be the "typical" single family lot having a minimum 75 foot
width within the sewer districts that were initially subdivided starting in 1998. These lots allow
for a house that is up to 55 feet wide to be constructed with the minimum standards.
Approximately at the time the West Waste Water Treatment Facility was constructed in 2004,
there was a market shift to the narrower R5 and R6 District lot with a 60 foot width. The initial
side yard setback of 10 feet was reduced to 7 feet in 2006 to increase the allowed house width
on a lot with a minimum width dimension from 40 feet to 46 feet.
Fire Incidents. Albertville Fire Chief Eric Bullen and the Department of Building Safety have
provided the following summary of residential fire incidents for the period between 2015 and
2018:
0)
Address
Zoning
District
Dwelling
Type
Min.
Interior
Side Yard
Setback
Secondary
Damage
To Adjacent
Structures
10469 80th St.
Al
SF
10ft.
8809 Labeaux Ave.
Al
SF
10ft.
7326 Kadler Ave.
Al
SF
loft.
7256 Maciver Ave.
Al
SF
10ft.
8532 Kadler Ave.
Al
SF
10ft.
9412 O'Day Ave.
R2
SF
10ft.
8060 O'Day Ave.
R3
SF
loft.
14399 89th St.
R3
SF
loft.
17190 591h St.
R4
SF
loft.
Yes
12444 76th St.
R4
SF
loft.
Yes
12054 78th St.
R4
SF
10ft.
15263 76th St.
R4
SF
10ft.
12460 65th St.
R4
SF
10ft.
7026 Martin Farms Ave.
R6
SF
7ft.
11209 77th St.
R6
TH
7ft.
Yes
7554 Landau Ave.
R6
SF
7ft.
10558 74th Ln
R6
TF
7ft.
7329 Kalland Cir.
R6
TH
7ft.
Yes
7278 Martin Farms Ave.
R6
SF
7ft.
Yes
7421 Queens Ave.
R6
SF
7ft.
Yes
NOTES:
SF = Single family
TF = Two family
TH = Townhouse
There were 20 fire incidents at residential properties between 2015 and 2018, which effected
less than one percent of the total number of homes in the City. Eight of these fire incidents
occurred on lots within rural zoning districts and there was no secondary fire damage to
surrounding properties. Of the 12 fire incidents on properties within urban zoning districts, two
were townhouse dwellings where damage affected attached dwellings but not adjacent
buildings. And, of the 10 fire incidents that occurred on single family properties within urban
zoning districts, there were four that cause secondary fire damage to adjacent structures.
Two of the urban single family fire incidents were within the R4 District and two were on
properties zoned R6 District. City staff has prepared maps showing the location of the primary
fire and the adjacent dwellings that incurred secondary fire damage. Only the fire incident at
7421 Queens Avenue (an R6 District lot) affected an adjacent dwelling setback the minimum
distance of 14 feet between structures. The house incurring secondary fire damage in the other
fire incidents are setback at least 24 feet, or more than the minimum setback required in the R4
District.
Building Code. Section R302 of the Minnesota Residential Building Code addresses fire
resistant construction requirements:
Exterior Wall Element
Min. Fire Resistance Rating
Minimum
Fire
Separation
Distance
Walls
Fire resistance rated
1 hour ASTME E 199 or UL 263
<5ft.
Non fire resistance rated
0 hours
>5ft.
Projections
Fire resistance rated
1 hour on the underside
>2ft. to
<5ft.
Non fire resistance rated
0 hours
>5ft.
Openings in
Not allowed
N/A
<3ft.
walls
25% maximum of wall
0 hours
3ft.
Unlimited
0 hours
5ft.
Penetrations
Comply with Sec. R302.4
<5ft.
None required
5ft.
The fire resistant construction measures apply only to those structures that are setback less
than five feet from property lines. Minnesota Statutes 326B.121, Subd. 2(C) prohibits the City
form requiring building code provisions regulating components or systems of any structure that
are different from any provision of the State Building Code. Unlike a storm shelter, these fire
resistant requirements pertain to construction of the building components that are regulated
by the building code. As such, the City cannot require fire resistant construction as outlined in
the table above for structures setback five feet or more from property lines.
Exterior Materials. The City does regulate exterior finish materials for residential structures
within the provisions of the Zoning Ordinance. Section 11-17-4.C.1 of the Zoning Ordinance
allows for use of the following exterior finish materials for residential dwellings:
■ Brick or custom masonry units (CMU) having a brick like appearance.
■ Glass.
■ Natural or artificial stone.
■ Exterior insulation and finish system (EIFS).
■ Fiber -cement exterior siding
■ Precast concrete panels
■ Masonry stucco.
■ Opaque panels.
■ Ornamental metal.
■ Wood such as cedar, redwood or cypress.
■ concrete block.
■ Aluminum siding.
■ Steel siding.
■ Vinyl siding.
E
Each of the four urban single family fire incidents that involved secondary fire damage to
adjacent dwelling(s) included melted vinyl siding, if not outright fire damage involving the
structural components of the adjacent building.
Chief Bullen indicates that a fiber -cement siding product like James Hardie Board has been
shown to be very resistant to heat and flame spread from adjoining structures. Fiber -cement
siding such as Hardie Board is not a 1 -hour rated fire resistant material, but they are non-
combustible even though it transfers heat through the siding. In Chief Bullen's experience, he
has observed minimal damage to homes with fiber -cement siding compared to fire damage to
houses with vinyl siding that had much less heat exposure that resulted in a total loss. A wood
based fiber siding such as LP Smartside has similar fire resistant properties as a cement based
product, but not to the same degree, according to Chief Bullen.
Chief Bullen's conclusion is that fire damage may still occur with as house having fiber cement
siding or between adjacent homes with minimum 10 foot setbacks. The goal of the Fire
Departments serving Otsego is to allow any extra time available for the occupants to get out -a
of the house involved in a fire and for the fire apparatus to arrive on the scene before the fire
penetrates into the interior of adjacent structures. For houses with vinyl siding that are
setback less than 10 feet from lot lines, the likelihood of preventing severe secondary fire
damage to adjacent buildings is very unlikely.
An exterior finish material such as fiber -cement or wood fiber siding is considered to be a
higher quality, more durable building material than vinyl. Requiring use of this exterior
material would improve the overall quality of housing within the City while also increasing fire
resistance. The intent of such a regulation can be supported by policies in the 2012
Comprehensive Plan. The Department of Building Safety estimates that the cost of a fiber -
cement exterior siding is 60 to 115 percent more expensive than a vinyl siding product, whereas
a wood -fiber exterior siding is 30 to 40 percent more expensive.
CONCLUSION
The 20 residential fire incidents between 2015 to 2018 occurred in less than one percent of the
houses in Otsego. Of these fire incidents, four occurred within homes on urban single family
lots, only one of which caused secondary fire damage to an adjacent home located at the
minimum setback distance required within the R6 District.
There does not appear to be a direct correlation between secondary fire damage and the
setback standards of adjacent dwellings based on the fire events that have occurred in Otsego
during this period. However, the experience of Fire Department officials serving Otsego
indicates that the risk to life and property is increased based on the proximity of homes to a fire
incident as well as the exterior finish materials.
5
The City cannot impose regulations requiring fire resistant construction as these are building
components regulated by the State Building Code and Minnesota Statutes prohibits adoption of
more restrictive regulations.
Use of exterior finish material is a zoning element that the City does regulate. Requiring an
exterior material such as fiber -cement or wood fiber siding on homes setback less than 10 feet
from side lot lines would reduce the risk to life and property of a residential fire incident by
increasing the time for a fire to spread to adjacent homes and allowing for a Fire Department
response.
An exterior finish material such as fiber -cement or wood fiber siding is considered to be a
higher quality, more durable building material than vinyl. Requiring use of this exterior
material would improve the overall quality of housing within the City while also increasing fire
resistance. Requiring fiber -cement or wood fiber siding for houses setback less than 10 feet
from lot lines would also increase wholesale and retail costs of house construction.
If the Planning Commission is considering adoption of a zoning requirement for fiber -cement
(or similarly fire resistant exterior material) for residential dwellings setback less than 10 feet
from lot lines, City staff recommends the next step in the process be to direct further research
as well as outreach to Otsego builders for input and comment on such a proposal.
The Planning Commission may also elect to recommend the City Council take no action to
amend the Zoning Ordinance based on the information available at this time.
C. Adam Flaherty, City Administrator/Finance Director
Tami Loff, City Clerk
Andy MacArthur, City Attorney
Lynn Paulson, Building Inspector
Jason Coombe, Building Inspector
Chief Eric Bullen, Albertville Fire Department
G
17190 59th Street
Overview
Legend
Roads
— CSAHCL
— CTYCL
— MUNICL
— PRIVATECL
— TWPCL
Highways
Interstate
— State Hwy
— US Hwy
City/Township Limits
❑ c
❑ t
aParcels
Primary Fire
Secondary Fire
12444 76th Street
Overview
Legend
Roads
-- CSAHCL
^— CTYCL
— MUNICL
— PRIVATECL
— TWPCL
Highways
Interstate
— State Hwy
— US Hwy
City/Township Limits
n
❑ t
❑o Parcels
Primary Fire
Secondary Fire
Homes 32ft. apart
7421 Queens Avenue
Overview
Legend
Roads
CSAHCL
! CTYCL
— MUNICL
— PRIVATECL
— TWPCL
Highways
Interstate
State Hwy
- US Hwy
City/Township Limits
❑ c
❑ t
Parcels
Primary Fire
Secondary Fire
Homes 14ft. apart
7278 Martin Farms Avenue
Overview
Legend
Roads
— CSAHCL
— CTYCL
— MUNICL
— PRIVATECL
— TWPCL
Highways
Interstate
— State Hwy
— US Hwy
City[Township Limits
0
0
0 Parcels
Primary Fire
Secondary Fire
Homes 24ft. apart