20200439 Ver 1_RFI_Letter_04242020_20200517

Kris Bass Engineering, PLLC
7334 Chapel Hill Rd
Raleigh, NC 27606
Office: 919.960.1552
Email: kbassAkbeng.org
5249 Vann St
Major Variance DWR #20200439
Additional Information Package
Dear Mr. Wojoski,
This letter and package provides additional information to support the Major Variance application for
5249 Vann St. The responses below include a list of the requests and supporting information. I have
consulted with the owner and their architect (Katie Dyer Designs) to prepare this info. Please let me know
if further information is needed and when a site visit can be scheduled.
Additional Information List and Responses:
1. The application package included a "Floor Plan Options - Sheet A 2.0" plan sheet only. Please
provide the full set of construction drawings for the proposed additions.
Response — A newer set of plans is provided with the package, prepared by Katie Dyer Designs. This
plan shows the intended design in plan view and an elevation view is also provided.
2. The proposed plans appear to include new deck additions in Zone 2 ("Floor Plan Options - Sheet
A 2.0"). These impacts do not appear on the buffer impact exhibits. Please explain why this
portion was excluded, or revise the exhibits and impact calculations to include it.
Response — The proposed home addition and the deck are included in the total buffer impacts. This may
be confusing because there is an existing deck on the property survey. The existing deck overlaps buffer
zone 2 and will be modified as part of this project. The owners would like to have this impact
authorized as part of this submittal. Please reference the 5249 Vann St Stormwater Plan — Sheet 1. This
sheet shows hatched impact areas that cover the entirety of the buffer that will be overlapped with the
proposed addition and deck. Some of these areas overlap existing impervious that already existed when
the home was purchased. I have checked all the impacts to ensure consistency with the latest design
and am confident that we are including and accounting the total of proposed impacts with this
submittal.
3. Avoidance and Minimization.
a. The application states that locating the additions on the west side of the property is
impractical due to construction constraints and building codes. (Section E, Question 1)
Please explain this impracticability by citing the specific building codes and construction
constraints.
Kris Bass Engineering, PLLC — 919.960.1552 — kbass kbeng.org

Response prepared by Katie Dyer Designs (Architect) — The west side of the house is made up of a
garage that was converted to livable space prior to the current owners, an unheated sunroom, and an
unheated storage room at the rear (SW side). The sunroom and storage room are constructed without crawl
space or slab, using near -grade wood framing and posts, similar to a deck. Bringing these spaces up to
current building code for heated space, either to utilize for the bedroom and bathroom, or as a
hallway/passage to an addition at the rear of the storage room would require addressing the following
building codes and construction restraints:
The Existing Wood Foundation
The existing floor joists are less than 6" above grade. The depth of the floor joists is currently unknown, as
is the quality and state of the joists, fasteners, and posts. Installing insulation, plumbing, or mechanical
systems in the floor will require access from the finished space and the creation of a hatch panel in the floor
if access is to be provided for any future need. There is no way to access the floor from the exterior.
Building codes that pertain to pressure -treated wood include:
R317.1: Protection of wood and wood -based products from decay ... #1 Wood joists when less than 18"
above grade and wood joists when less than 12" above grade. #5 Wood siding and sheathing when having a
clearance less than 6" from the ground.
R317.2: Ground Contact. All wood in contact with the ground... shall be approved pressure -preservative
treated wood suitable for ground contact -use.
R317.3: Fasteners and connectors in contact with preservative -treated wood
Section R402.1 Wood Foundations
R402.1.1 Fasteners
R402.1.2 Wood Treatment
R403.2 Footings for Wood Foundations
Insulation
If part or all of the existing space is to be conditioned, the walls, floor, and ceiling would need to be
insulated to today's standards. The depth of the existing floor joists and it's proximity to the ground at the
sunroom and storage are a potential problem that would require special design and approvals that would
make this impractical.
N1101.11 Protection of Exposed foundation insulation @ slab edges
N1102.2.10 Slab -on -grade floors
N1102.1 Building Thermal Envelope: min R-15 walls, R-19 floor, R-38 ceiling, R-10 slab edges
N1102.2.8, Floors: floor framing cavity insulation shall be installed to maintain permanent contact with the
underside of subfloor decking.
N1102.2.4 Access hatches and doors
b. The plans provide for a deck and patio to remain. Please explain why minimization can
not be accomplished by relocating the deck and patio and allowing the additions to be
constructed in their footprints.
Response prepared by Katie Dyer Designs - Adding finished space in the current deck and patio
location would create an unusual roofing condition, either having to attach to two sides of an L-shaped
gable structure, use less than typical roof pitches (requiring flat roof materials), or would extend tall, up
past the ridge of the current house and be visible from the street. Additionally, it would eliminate
exterior access, light, and view from the existing kitchen and sunroom.
Kris Bass Engineering, PLLC — 919.960.1552 — kbass kbeng.org

c. The plans show an impact area for additional stairs from the proposed bathroom the
basement. Please explain why this can not be eliminated to demonstrate minimization.
Response prepared by Katie Dyer Designs — These stairs are required for fire safety. In the case of
basements, egress without having to go back up through the house is required by code:
R310.1: Emergency escape and rescue opening required. Basements, habitable attics, and every sleeping
room shall have not less than one operable emergency escape and rescue opening.
R310.2.3: Window Wells
R310.2.3, Ladder and steps
R310.3, Emergency escape and rescue doors
d. The cistern and rain garden SCM are proposed in Zone 2 of the buffer. Please
demonstrate why it is not practicable to location the rain garden and cistern outside of
the buffer.
Response prepared by Kris Bass Engineering — The proposed cistern and rain garden were optimized to
maximize capture from the proposed buffer impacts. Although they are located in Zone 2, this is the only
location which will allow the treatment and dissipation of necessary outflows to the buffer. The proposed
addition will require roof gutters surrounding the existing patio and proposed deck, which will outlet in
buffer zone 2. The proposed cistern is sited to collect this outflow, which requires a location at the corner
of the addition. The proposed rain garden is located in a nearby, cleared area of the buffer. This area has
the appropriate soils and elevation to facilitate a safe, gravity fed rain garden system. The completed rain
garden will increase infiltration and recharge the shallow buffer groundwater. Overall, the combined
cistern and rain garden system will provide stormwater treatment capacity in excess of the proposed
impervious additions.
4. The application states that the stream was moved on to the property boundary causing the
hardship. (Section E, Question 3). Please explain when and under what circumstance the
stream was moved and who conducted the work, if known.
Response prepared by Kris Bass Engineering — The straight alignment of the stream and current depth
is an indicator of past impact. A natural stream with a similar watershed would have a sinuous pattern
and a bankfull depth of less than 1.5 feet. The existing stream has a straight pattern and a depth of 3+
feet. The location of the stream along the property boundary is further evidence that the stream was
moved to facilitate the adjoining lots and building constructions. It is unclear when these impacts
occurred, but seems likely that they were completed as part of the original lot development prior to
stream and buffer rules.
It is my opinion that the historic stream alignment would have winded to the east and off the owners
property (further from their home). This is based on the soil maps (1970), my interpretation of the valley
shape, and the construction of the adjacent buildings. If the stream had been left in this original
alignment, the buffer zones may not interfere with the existing or proposed building.
The existing intermittent stream has been dug into the shallow groundwater table and is the primary
reason for this classification. The stream originates with a stormwater pipe outfall and outlets
downstream of this property into a pond/wetland complex. The stream incision and stormwater flow
dynamics likely impact the functionality and aquatic habitat of the reach. This incision also impacts the
current functionality of buffers due to influence on the natural groundwater gradient and loss of historic
floodplain connection.
Kris Bass Engineering, PLLC — 919.960.1552 — kbass kbeng.org

5. Please demonstrate how the physical nature of the property (i.e. size, shape, topography) is
different from that of neighboring properties. (Section E, Question 3).
Response prepared by Kris Bass Engineering — This is the only property on this street that has the
existing home built on top of stream buffer zones. Other nearby homes benefit from the stream being
historically buried into stormwater pipes or a historic move of the stream away from their building. This
provides these owners with the ability to pursue additions without the restriction of buffer rules.
6. A site visit will be necessary for the review of the application. This item requires no
response from you, but is provided for informational purposes.
Thank you for the opportunity to provide this additional information and clarify the intent and details of
this submittal. We look forward to a site visit and discussion. The owners are committed to
environmentally responsible project and look forward to working with you to obtain your support for the
proposed work.
Sincerely,
Kristopher Bass, PE
Kris Bass Engineering, PLLC — 919.960.1552 — kbass kbeng.org