REV3 BLD2023-0027+SUMMARY_OF_CHANGES_UPDATED+8.10.2023_4.01.30_PM+3719733Revision Cover Letter & Summary of Changes BLD2023-0027
Revisions to permitted plans
Hill Addition 633 Alder Street Edmonds, WA
BLD2023-0027
August 8, 2023 (updated August 9)
To Whom it May Concern at the City of Edmonds Dept. of Planning,
We write with a summary of changes to BLD2023-0027 that were made primarily to facilitate improved thermal
insulation to improve climate resilience and reduce long-term energy use for this residence beyond the
minimum required levels. A small number of additional minor revisions are also included. A summary of the
revised submission is included below.
Please do not hesitate to reach out with any questions. Thank you very kindly for your time.
Sincerely,
Lawson Andrew Hill
Owner — 633 Alder St, Edmonds, WA 98020
Cell: 603 986-8523
Email: L.Drew.Hill@gmail.com
Table of Contents
ImprovedInsulation........................................................................................................................ 1
Optimize New Crawlspace Ventilation and Improve Ventilation of Existing Crawlspace .................... 2
Minor Alteration of Planned West Window Bump Out..................................................................... 3
Changesto Kitchen Island............................................................................................................... 3
New Entry Doors and Window Corrections...................................................................................... 3
DemolitionUpdate......................................................................................................................... 3
Footings......................................................................................................................................... 3
No change to house -garage separation........................................................................................... 3
Improved Insulation
We have updated our plan to include Continuous Insulation ("Cl") on exterior walls where possible. Where not
possible due to setbacks, exterior walls have been upgraded with interior -side foam furring on studs to
improve/reduce thermal bridging and avoid setback encroachment. A map of changes can be found on A-6
"WALL SECTION MAP". Nearly all new exterior walls (2x6) and existing exterior walls (2x4) outside of the
setback will now include 2" of mineral wool battened to studs using 1x3 furring (also creating an air gap) with
cladding nailed directly to furring. This updated wall assembly is detailed on A-5 Details A, B, and C and A-6
Detail D. Contractor has measured distances from the edge of the newly poured stemwalls and plinths to
Revision Cover Letter & Summary of Changes BLD2023-0027
relevant setbacks to ensure exterior wall assembly thicknesses do not encroach on any setbacks (A-2 adjusted
accordingly).
1. Exterior insulation type (mineral wool, R4/inch) was chosen to allow bidirectional drying.
2. A-5 Details A, B, and C and A-6 Detail D Exterior insulation thickness was chosen to meet or exceed the
R ratio of exterior:interior insulation ("%CI") required to avoid reaching dewpoint at the sheathing
under Snohomish County's ASHRAE 90.1 climate zone — Climate Zone 4C as depicted in 2018 IRC
N1101.7 (R301.1). Conservative %CI guidance is taken from 2018 IRC Table N1102.1.2 (R402.1.2):
a. 2x4 walls with Cl: R3.5 (or higher) exterior with R15 interior (>= 23% CI)
i. We will use R15 with R8 exterior (53% CI)
b. 2x6 walls with Cl: R5 (or higher) exterior with R20 interior (>= 25% CI)
i. We will use R21 with R8 exterior (38% CI)
3. The existing West wall will receive partial Cl, with Cl following Detail A-5 C from the NW corner
southward to the window bump out, ending just before the front setback begins (even with the South
wall of the new window bump out) so as not to encroach. The remainder of the wall's assembly will
remain unchanged.
4. A-6 Details E and F. Interior studs (2x4) of existing exterior walls inside of the front setback (A-6 E) as
well as the mudroom wall between the garage and house (A-6 F) will receive foam -backed furring strips,
breaking thermal bridging and increasing insulation bays to 5.25" (S existing walls) and 7.25" (mudroom
North wall).
a. %CI requirements do not apply here, as all insulation is on the interior.
5. A-6 has been updated with guidance from James Hardie Tech Note #19, with details that nicely
demonstrate the manufacturer's suggested fastening approach, relevant technical tables from the
manufacturer, and fastener placement when using a non-nailable substrate > 1" (e.g., our exterior
insulation). The overall nature of the images from these documents is to inform FASTENER best
practices, and is not intended to supersede our architect's details A-F on pages A-5 and A-6 (which do
not include fastener guidance and so should pose no conflict to manufacturer's fastener guidance).
a. USTB 19 1 Version 3. Available: <
https://www.mameshardie.com/JamesHardieMainSite/media/Site-
Documents/TechnicalBulletins/19-Ih-over-advanced-framing-or-continuous-insulation.pdf >.
Accessed Aug 7, 2023.
Optimize New Crawlspace Ventilation and Improve Ventilation of Existing Crawlspace
Crawlspace ventilation changes (see S2):
1. A Class I vapor barrier will be installed per code on the ground of entire crawlspace to allow 1ft2/1500ft2
ventilation requirement. Total crawlspace area — 1578.45 sf, thereby requiring 152.39 si ventilation. See
Details A, B, C on A-5 and D, E, F on A-6 for updates to vapor barrier installation & interior insulation.
2. 152.39 si ventilation will be achieved in a way that positions both new and existing crawlspace to
receive cross -ventilation (total achieved = 155.8 si):
a. One 2.5" hole to be drilled per engineer's specifications in the NW wall of existing foundation.
Another hole of same parameters to be drilled in SE corner of existing crawlspace to facilitate
cross ventilation.
b. Keep two 73 si vents in the new crawlspace in locations that facilitate cross ventilation.
c. Close the remaining unneeded foundation vents that were poured into the new foundation
(from the original design).
d. All vents to be covered with %" (or less) screening per code.
Revision Cover Letter & Summary of Changes
BLD2023-0027
Minor Alteration of Planned West Window Bump Out
West side window bump out has received slightly altered dimensions to and will now have a gabled roof. See A-
4 elevation.
Changes to Kitchen Island
The existing kitchen island will be resized and extended to and along the hallway wall. See A-2.
New Entry Doors and Window Corrections
1. New front door and new deck door. See and A-2 and A-5.
Corrected error originally showing OFFICE/FLEX SPACE West window as a "replacement" with "existing
header". Now indicates that this is a newly cut window with new header.
An error stating South window of Bedroom 3 as 36"x61" has been corrected — window will be 36"x60"
See A-2.
Demolition Update
1. Update Demolished Area estimation on A-1 from 261 sf to 319 sf to account for unanticipated
demolition. Consequently, updated "TOTAL NEW CONDITIONED" estimate on A-1 from 1224sf to
1282sf. No new energy credits required.
2. Updated demolition cost estimates on Demo Worksheet to account for newly demoed area and other
new demo related to this resubmission. Also updated after purchase of replacement windows to more
accurately reflect replacement cost of windows.
Footings
1. Replace existing pier block with a 2' x 2' x 10" footing pad to support a 4x6 beam. This is approximately
located under small front (South) bathroom sink, and was observed by inspector on 8/1 visit. See S2.
2. (Restating a recently submitted revision) New footer added per previous engineer -stamped 8/1
resubmission. See S2 and SSK-P via "BLD2023-0027_Architectural_Plan_08-08-
2023_18_58_38_BLD2023-0027 Architectural_Plan_08-01-
2023_07_07_12_H i I I_Floo r_Revis ion_072523"
a. This point is simply restating a revision that was submitted to the city on 8/1.
b. The 2-page document "BLD2023-0027— Architectural — Plan —08-08-2023-18-58-38—BLD2023-
0027_Architectural_Plan_08-01-2023_07_07_12_Hill_Floor_Revision_072523" — which depicts
"Hill Residence 111 Floor Framing Plan Partial" and SSK-P (dated "07.25.23") — was resubmitted
in this 8/8 revision to ensure completeness of our documentation, however it is unchanged
from its original 8/1 submission.
No change to house -garage separation
Re -iteration that we will not be connecting the garage and house. SSK M and SSK N (originally Created to depict
a House/Garage interface) are still crossed out and continue to be irrelevant to the project.