HomeMy WebLinkAboutSD-24-11 - Supplemental - 0252 Autumn Hill Road (2)
180 Market Street, South Burlington, Vermont 05403 | 802-846-4106 | www.southburlingtonvt.gov
TO: South Burlington Development Review Board
FROM: Marla Keene, Development Review Planner
SUBJECT: #SD-24-11 252 Autumn Hill Road
DATE: August 6, 2024 Development Review Board meeting
PROJECT DESCRIPTION
Final plat application #SD-24-11 of Allyson and Vincent Bolduc to subdivide an existing 16.46 acre
lot developed with a single family home and accessory structures into two residential lots of 2.0
acres and 14.46 acres, retain the existing single family home and accessory structures on the 14.46
acre lot, and construct a duplex on the 2.0 acre lot, 252 Autumn Hill Road.
CONTEXT
The Board reviewed the application on July 16, 2024. Immediately prior to the Board’s review, the
applicant submitted revised plans, which are incorporated into this report. There were also
outstanding issues pertaining to interdepartmental review of the applicant’s proposed project.
This memorandum provides a review of the revised materials & an update on interdepartmental
review. Where a criterion was satisfied prior to the July 16 hearing, and no changes are proposed
affecting compliance with the criterion, the criterion is omitted from this memorandum.
COMMENTS
Development Review Planner Marla Keene and Director of Planning and Zoning Paul Conner,
hereafter referred to as Staff, have reviewed the plans submitted by the applicant and offer the
following comments. Numbered comments for the Board’s attention are in red.
A) ZONING DISTRICT AND DIMENSIONAL STANDARDS
SEQ-NRP & SEQ-NRT
Zoning District
Required Existing Proposed Lot 1 Proposed Lot 2
Min. Lot Size 2 9,500 sf 16.44 ac2 1.98 ac 14.46 ac
Max. Building Height 28 ft pitched
roof
Unknown 28 ft Unknown
Max. Building Coverage 20% 0.5% 0% 0.6%
Max. Overall Coverage 40% 2.5% 0% 3.7%
(1) Min. Front Setback 20 ft Unknown 20 ft Unknown
(1) Min. Side Setback 10 ft Unknown 10 ft Unknown
(1) Min. Rear Setback 30 ft Unknown N/A Unknown
1. On July 16, the applicant indicated they had provided the existing and proposed setbacks on the
revised plans. However they appear to have only provided this information for the proposed
carve-out lot. Staff considers the standard setbacks to apply to the existing lot and to the retained
lot and recommends the Board accept the information as provided.
B) ENVIRONMENTAL PROTECTION STANDARDS
The subject property is encumbered by habitat block, Class II wetland, and Class II wetland buffer.
Class II wetlands and buffers are considered hazards, while habitat block is considered a Level 1
resource.
12.04 Habitat Block Overlay District
E. Substantially-Habitat Block-Covered Lots.
A lot containing a combination of Hazards and Level I Resources exceeding seventy (70) percent of
the total lot area is eligible for relief from Habitat Block standards in the following manners:
The applicant has reported that of the 16.44 acre lot, 13.66 acres, or 83%, is located within hazards
or level 1 resources.
(1) As a Conservation Planned Unit Development, subject to the standards of Section 15.C.05; and,
(2) The applicant is entitled to re-designate a portion of the Habitat Block, to allow for thirty (30)
percent of the total parcel area as Buildable Area.
30% of the 16.44 acre parcel is 4.93 acres.
The applicant shall provide a proposed redesignation to the Development Review Board with
land designated as, and added to, the parcel’s Buildable Area in the following order:
• First: Land not a Hazard or Level I Resource;
• Second: Land that is not characterized by a preponderance of mature trees;
• Third: Land within Habitat Blocks, excluding Core Habitat Block Areas or areas which
would sever a Habitat Connector.
• Fourth: Land within Habitat Blocks, avoiding Core Habitat Block Areas to the greatest
extent possible;
(a) Calculation: Land shall be selected from first to fourth. If all applicable land on the lot from
one category is designated as Buildable Area, and the allotment of thirty (30) percent of
the total parcel area has not been reached, then land from the next category shall be
selected.
The applicant has provided a chart on sheet 1 indicating that 2.78 acres is not a hazard or
level 1 resource. The applicant is therefore permitted to re-designate an additional 2.15
acres of Habitat Block. Only lands that are encumbered by habitat block and not by other
resources may be re-designated as buildable area, by virtue of this criterion being
embedded within the habitat block standards.
The applicant has proposed to re-designate a 0.24 acre area of land that is not
characterized by a preponderance of mature trees and outside the wetland buffer shown
in orange on the provided Overall Plan, and a 1.04 acre area of land that is characterized
by mature trees but is outside of the Core Habitat Block Areas shown in yellow on the
provided Overall Plan.
1. Upon closer review of the regulations, the lands that are within the wetland, wetland buffer,
and non-excluded habitat block must not be subdivided. Therefore Staff recommends the
Board require the applicant to revise their subdivision, either by matching the proposed lot
lines to the buildable area line or by proposing a different subdivision line that excludes all
non-excluded protected natural resources. Subdivision standards and their relevance to
natural resources are discussed under 15.A.11 and 15.A.12 below.
(c) Any land excluded from Habitat Blocks regulated under this subsection and redesignated
as Buildable Area shall remain subject to all other provisions of these Regulations.
This provision is important because only the land within the excluded area may be
developed in any manner. Details are discussed below.
12.06 WETLAND PROTECTION STANDARDS
The applicant has identified Class II wetlands and the associated 100-ft buffers on their plans.
Development within the Class II wetland or buffer is generally prohibited. The applicant is
however proposing to subdivide the wetland, which is prohibited and discussed above and below
under 15.A.11 and 15.A.12
C) SUBDIVISION STANDARDS
15.A.11 General Standards
A. Development Suitability. The applicant must demonstrate that the land to be subdivided
is physically suited for its intended use and the proposed density or intensity of development, and
that the proposed subdivision will not result in undue adverse impacts to public health and safety,
environmental resources as identified and regulated under Article 12, neighboring properties and
uses, or public facilities and infrastructure located on or within the vicinity of the land to be
subdivided.
(1) Physical Site Constraints. Land that is physically unsuited for development, including land that
is characterized by periodic flooding, poor drainage, shallow soils, landslides, environmental
site contamination or other known physical hazards or constraints, must not be subdivided for
development unless the applicant can demonstrate that such limitations can be overcome,
remediated, or mitigated as necessary to allow for subsequent development.
Staff considers this criterion prohibits subdivision of land that is unsuited for development, and
is substantiated by 15.A.12A below.
C. Development Context
1) Overlay Districts. The subdivision must also meet applicable overlay district standards
under Article 12.
Overlay districts applicable to this lot include natural resource protection districts
discussed under Article 12 above.
2) Multiple Districts For the subdivision of land located in more than one zoning district, the
district regulations specific to that portion of the subdivision within each zoning district
shall apply, except as specified for a Planned Unit Development under Article 15.C.
This is a lot located in multiple districts, but the subdivision is proposed only in the SEQ-
NRT therefore compliance with this criterion is not a concern.
3) Compliance with Other Regulations . Subdivisions, including building lots, dwelling units,
and supporting facilities and infrastructure, must also be designed, configured, and
constructed to comply with other relevant standards under these Regulations and other
city ordinances and standards in effect at the time of application, including those listed
below.
• Official Map, adopted under 24 V.S.A. § 4421
There are no official map features affecting this parcel.
• Capital Improvement Program, adopted under 24 V.S.A. § 4430
The Deputy Director of Capital Projects indicated on 7/9/2024 they did not have any
comments on the proposed project.
• Department of Public Works Standards
The Director of Public Works reviewed the provided plan on June 19, 2024. The applicant
provided responses on July 19, 2024 and on July 19, 2024 the Director of Public Works
indicated that their only outstanding comment was as follows.
• We accept services at the point of connection, so we will consider the sewer
service private until the point when it connects to the existing manhole (with rim
elevation 363.3') on Windswept lane. Alternatively, you could install a manhole
where the reducer is located and we would accept the system at that location.
Staff recommends the Board include the remaining comment as a condition of approval.
• Fire Prevention and Safety Ordinance
Comments of the Fire Marshal are provided below.
• Water and Cross Connection Ordinances
Comments of the South Burlington Water Department Director were included in the Staff
report for July 16.
• Sanitary Sewer and Stormwater Ordinance
The City Stormwater Section reviewed the provided plans on July 3, 2024, and the updated
plans on July 26, 2024. The applicant made final modifications to the plans on July 26,
2024, and the City Stormwater Section indicated on July 29, 2024 that they had no further
comments.
• Impact Fee Ordinance
• E-911 Ordinance
4) Compliance with an Approved Master Plan
There is no approved Master Plan governing this parcel.
D. Development Connectivity
The applicant must demonstrate that the subdivision, to the extent physically feasible, is
configured and laid out to maximize connections with adjoining parcels and neighborhoods, and
to avoid creating isolated and disconnected enclaves of development, except where necessary to
separate incompatible land uses, or to avoid undue adverse impacts to resources identified for
protection under Article 12. Accordingly, the applicant must demonstrate that the subdivision is
laid out to connect with and extend existing and planned streets, sidewalks, recreation paths,
transit routes, and utility and greenway corridors located adjacent to or within ½-mile of the
subdivision, or as indicated on the City’s Official Map. Off-site improvements necessary to serve
the proposed subdivision must be provided in accordance with 15.A.18.
The applicant is proposing to access the development lot via Windswept Lane. Specific roadway
standards are addressed in 15.A.14.
15.A.12 Resource Protection Standards
A. Resource Protection.
The applicant must demonstrate that the proposed subdivision has been configured and laid out
to:
(1) Incorporate significant natural, historical, and scenic features located on the parcel or tract to
be subdivided;
Staff considers this criterion not applicable.
(2) Avoid and exclude Hazard and Level I Resources identified for protection under Article 12 from
parcelization, physical fragmentation, and development; and,
Staff considers this standard would not apply to excluded habitat block areas.
(3) Minimize and mitigate the adverse impacts of land subdivision and development on Level II
Resources identified for protection under Article 12.
Staff considers this criterion not applicable.
B. Applicability.
Resource protection standards under this section apply to all subdivisions of land, unless modified
by the DRB in accordance with resource-specific allowances under Article 12 and the following:
(1) The DRB may modify or waive a resource protection standard under this section within a
Transect Zone Subdivision or a Planned Unit Development only as necessary to achieve or
maintain the planned type and pattern of development and to allow for the logical
extension of supporting facilities, infrastructure, and services.
The applicant is not proposing a transect zone subdivision or planned unit development
therefore this criterion is not applicable.
(2) Notwithstanding a subdivision waiver or modification, proposed subdivisions shall
comply with all other applicable resource protection standards under these Regulations,
including any requirements for on- or off-site impact mitigation.
Necessary plan edits are discussed below. Staff considers on or off site mitigation to be
unnecessary.
D. Resource Protection Areas.
Resource protection areas to be incorporated in subdivision layout and design include Hazards,
and Level I and Level II Resources identified for protection and regulated under Article 12.
(1) Subdivision boundaries and lot lines must be located and configured to avoid or, where
deemed necessary by the DRB, to minimize the subdivision, parcelization, and physical
fragmentation of resources located on contiguous parcels, and on the tract or parcel to be
subdivided.
Staff considers there to be no reason the Board should permit subdivision or parcelization of the
wetland and wetland buffer or remaining habitat block.
(2) Contiguous Hazard and Level I Resource protection areas that exceed the minimum lot size
must be set aside and identified on the subdivision plat, and in associated legal documents, as
“Conservation Lots” to be maintained and managed in single or common ownership, or under
a conservation easement held by the City or qualified third party, such as an established land
trust. As a condition of subdivision approval, future subdivision of conservation lots shall be
prohibited except where all land is being conveyed for conservation purposes, as also noted on
the subdivision plat.
2. As a carve-out, Staff considers that conservation of the resource protection areas to be
unnecessary at this time but in addition to modifying the subdivision to avoid crossing
protected natural resources, Staff recommends the Board require the applicant to modify
the subdivision plat to identify the resource protection areas on the plat.
(3) Hazard and Level I resource protection areas must be excluded from the calculation of
Buildable Area. Building lots and building envelopes are prohibited within these areas, except
as necessary to accommodate resource-dependent facilities (e.g., water and wastewater
treatment facilities, public or community recreation facility), as specified under Article 12, or as
allowed under this subsection.
This criterion has been addressed and is discussed above under 12.04E above.
(4) A building lot may extend or encroach within a delineated resource protection area only to
the extent necessary to meet minimum lot size or frontage requirements for the zoning district
in which the lot is located.
Staff considers lot size and frontage requirements are met without encroachment.
(5) A building lot may incorporate a Hazard, Level I, or Level II resource area that is less than
the required minimum lot size; however, in this case the DRB may require the delineation of a
building envelope that excludes the delineated resource area, as shown on the subdivision plat
and pinned on the ground, as necessary to limit the siting of buildings, other structures, and
parking areas to the developable portion of the lot.
Not applicable
(6) Encroachments within resource protection areas, including transportation and utility
corridors, are limited to those allowed, subject to DRB review and approval, under Article 12,
Staff considers no encroachments beyond the habitat block exclusion discussed above to be
permitted.
(7) A resource protection area may be improved to serve as green infrastructure (e.g., for
stormwater management or flood control), or as a public amenity serving the subdivision,
consistent with applicable standards under Article 12, to the extent that this does not interfere
with its critical natural functions or intended use.
No green infrastructure improvements are proposed.
15.A.14 Street Network
E. Access and Circulation.
The applicant must demonstrate that the street network is arranged to meet applicable access
management, traffic, and pedestrian circulation standards under these Regulations, including
criteria for site plans under Article 14, Transect Zone Subdivisions under Article 8, or a type of
Planned Unit Development under Article 15.C; and, for state highways, VTrans Access Management
Program Guidelines in effect at the time of application. Unless otherwise specified under these
Regulations, the street network, including the location and arrangement of streets, must be
designed to:
(9) Minimize vehicular access points (curb cuts) to abutting properties and building lots along
pedestrian-oriented street frontage; and provide, where physically feasible, shared vehicular
access to frontage and other abutting building lots via rear alleys, side streets, service lanes,
shared driveways, or rear cross connections between adjoining parcels.
3. The applicant has shown on their subdivision plat that the access easement across Lot 2 for
the benefit of Lot 1 does not actually touch Lot 1. Staff recommends the Board require the
applicant to reconfigure the lots and easements so that there is actual access to Lot 1, and
update the lot area, buildable area, and habitat block exclusion area computations
accordingly.
15.A.16 Blocks and Lots
C. Lots.
All lots must be laid out to logically relate to topography and their intended use or purpose.
Building lots must be laid out within existing and planned street and block configurations, in such
a way that they can be developed in full compliance with their intended use and these Regulations.
Unless otherwise specified under these Regulations as applicable to the subdivision:
(1) A building lot generally must be rectangular in shape, with side lot lines that are
perpendicular or radial to the abutting street, and rear lot lines that parallel the street,
except as necessary to accommodate existing rights-of-way or other physical site
constraints (see Figure 2-1, Lots, Yards and Lot Lines). Irregular or oddly shaped building
lots, including flag and through lots, are prohibited, except for:
(a) A flag lot, with a minimum of fifteen (15) feet of frontage on the abutting street, as
necessary to accommodate a back-lot subdivision and infill development within an existing
subdivision, block pattern, or development;
(b) A triangular or trapezoidal building lot defined by abutting streets that otherwise has
sufficient street frontage and lot area to meet minimum lot requirements; or
(c) A through lot with frontage on two parallel or intersecting streets that cannot be further
subdivided under minimum lot requirements, provided that front setback requirements
can be met on both streets.
While none of the specific exceptions apply, Staff recommends the Board permit
modification of this standard requiring generally rectangular lot lines due to the physical
site limitations created by the wetland and habitat blocks as permitted under 15.A.01B(3).
(2) Building lots should be oriented and configured to minimize lot width (frontage) along the
street. The preferred building lot width to depth ratio is 1:2; however, a ratio of 1:1 to 1:5
may be allowed as necessary to accommodate physical site constraints, stormwater
drainage, or rear lot access and parking.
The lot is proposed to be approximately 1:1.5 to accommodate physical site constraints.
Staff considers compliance with this criterion should be reevaluated when comments
pertaining to buildable area and habitat block re-designation have been addressed.
15.A.18 Infrastructure, Utilities, and Services
C. Fire Protection
The subdivision must be laid out to ensure that adequate fire protection can be provided in
accordance with City specifications.
a) Subdivision layout and design must also comply with applicable City and state public
safety and fire codes in effect at the time of application, including standards for minimum
separation distances between structures, street width, water flow and pressure, fire
hydrant installation, sprinkler systems, and emergency vehicle access.
b) Fire hydrants connected to the municipal water system must be located and designed to
meet City specifications, as recommended by the Department of Public Works and City
Fire Marshal. For a subdivision that is not connected to the municipal system, the DRB
may require the subdivider to install hydrants, fire ponds or other measures necessary to
provide adequate fire protection, as recommended by the Fire Marshall.
The Fire Marshal provided the following comments on the proposed driveway on June 18, 2024.
Applicant responses were provided on July 18, 2024 and are embedded in green below.
As these proposed structures are more than 150’ off the public road. In order to be compliant
with the minimum requirements NFPA 1- Chapter 18, the following shall apply:
- The private drive shall be widened and capable of supporting >60,000 lbs. apparatus
The driveway is 14’ wide and meets the minimum clearance of 10’ from centerline on each
side. The driveway will be capable of supporting >60,000 lbs.
- Minimum vegetation clearance from the improved drive way centerline shall be maintained
at 10 feet in width on either side of the center line, to the minimum height of 13 feet 6 inches
to allow emergency vehicles unfettered access to the structures.
The driveway is 14’ wide with 8’ swales on each side, therefore we are proposing 14’ clearance
from centerline which is greater than the required minimum of 10’.
- The road to the single family with the ADU, shall have an appropriate fire apparatus turn
around at its terminus
A fire turnaround has been incorporated at the end of the proposed driveway, mirroring the
dimensions of the existing turnaround at the end of Windswept Lane. Additionally, pull-off
areas measuring 20 feet in width and 20 feet in length have been added every 150 feet. One of
these pull-offs coincides with the driveways serving the duplex lot, so we propose using these
driveways as a pull-off.
- All new dwellings shall install a fire protection sprinkler system.
Understood. A 2” municipal service is proposed to the 6-acre lot.
D. Stormwater Facilities
The applicant must demonstrate that stormwater management system serving the subdivision
has been designed to meet City standards and specifications under Article 13 of these regulations
and the South Burlington Ordinance Regulating the use of Public and Private Sanitary Sewerage
and Stormwater Systems.
Comments of the City Stormwater Section are above.
RECOMMENDATION
Staff recommends the Board work with the applicant to address the issues identified herein.
Respectfully submitted,
Marla Keene, Development Review Planner