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Harrison LetterWESTSHORE DESIGN ENGINEERS, P.C. 6279 JOHNSTON RD. ALBANY Ϳ NEW YORK Ϳ 12203 WestShore Design Engineers ۅ 6279 Johnston Rd. ۅ Albany, NY 12203 ۅ 518.313.7153 Subject: Harrison Residence 589 Coles Meadow Rd. Northampton, MA Dear Trinity Solar, The following references the Harrison Residence in Northampton, MA: 1. Existing roof framing: Conventional framing is 2x10 at 16”o.c. with a 22’ max. span (horizontal rafter projection). This existing structure is capable to support all the loads that are indicated below for this photovoltaic project. 2. Roof Loading: - 4psf dead load (modules plus mounting hardware) - 40psf ground snow load - 6.9psf roof materials (2.9psf 2x10, 1.5psf sheathing, 2.5psf asphalt shingles) - Exposure Category B, 125mph wind (3 sec.) This installation design will be in general conformance to the manufacturer’s specifications, and complies with all applicable laws, codes, and ordinances, specifically the International Building Code/IBC 2015 and International Residential Code/IRC 2015 including all MA regulations and amendments. The spacing and fastening of the mounting brackets is to have a maximum of 48”o.c. span between mounting brackets and secured using 5/16” diameter corrosive resistant steel lag bolts. To evenly distribute the load across the roof rafters, there shall be a minimum of 2 mounting brackets per rafter & min. 3” penetration of lag bolt per bracket, which is adequate to resist all 125mph wind live loads including wind shear. Per NDS Section 11.1.4 clearance holes equal to the diameter of the shank need to be bored into primary a primary framing member for the full length to the threaded portion of the screw to avoid splitting of the framing member. Thank you. Westshore Design Engineers 7/22/2024 John Eibert Nicolas Nitti, PE Project Coordinator President To: Trinity Solar 4 Open Square Way #410 Holyoke, MA 01040 Date: July 22, 2024 Ref.: 24070543