Silver_Signed Permit App scan with NES signatures and submittalsVreeland Design Associates
An integrative approach to design engineering and site planning
116 River Road, Leyden, MA 01337 Phone: (413) 624-0126
Email: dvreeland@verizon.net Fax: (413) 624-3282
Date: February 20, 2024
To: Justin Annis
NorthEast Solar
136 Elm Street
Hatfield, MA 01038
From: David Vreeland, P.E.
Vreeland Design Associates
Re: Josh Silver, 117 Maplewood Terrace, Northampton, MA: Structural assessment of existing
house and addition roofs to support the proposed PV solar panel arrays.
I have investigated the existing roof framing in the areas of the proposed PV solar panel
installations. Based on the Assessor’s records, the main 2-story, 20’x 25’ house was constructed in
1864. A 14’x 25’ addition built off the back east facing gable end appears to have been
constructed at a later date. Around 2012, a 2nd floor addition was constructed over the earlier 14’x
25’ addition. 7 PV solar panels are to be installed on the main house south facing roof and 7 solar
panels on the south facing roof of the addition. The main house roof is framed with 2”x 5” rafters
installed 24” on-center, spanning 9’-8” with a 12/12 pitch. The rafters are secured to the attic 2x6
floor framing preventing the roof from spreading. Full length 2x10s have been sistered to every
other rafter. The roof appears relatively straight and true. Based on the grain pattern and limited
number of knots the original rafters appear to be Douglas-fir, No.1 & better. Plywood sheathing
has been installed over the original 1” roof boards. The newer 2nd floor addition roof is framed
with 2x4 scissor designed roof trusses, installed 24” on-center, spanning 14’ with a 12/12 pitch.
The roofing is composite asphalt shingles.
I have reviewed the mounting details for the proposed PV solar panel arrays. Based on my
calculations and a PV solar panel unit weight of 46± lbs, with the attachment points of the main
house solar panel array placed at a maximum of 4’ on center and secured to the 2x10 reinforced
rafters as often as possible and placed a maximum of 4’ on-center and staggered to minimize the
load to any one roof truss on the addition, the roof framing of the main house and addition are
adequate to support the proposed PV solar panel arrays and the snow and wind load requirements
of the current 9th Edition of the MA State Building Code for the City of Northampton.
Please contact me if you have any questions or need additional information.
Sincerely,
David Vreeland, PE
Vreeland Design Associates