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32A-124 PREVIOUS-FeasibilityMemo-010918 COMPLIANCE STRATEGY MEMO Coldham Architects Page 1 of 2 Coldham Architects 155 Pine St. Amherst, MA 01002 Tel 413.549.3616 Fax 413.549.6802 www.ColdhamArchitects.com To: Tony Patillo, Building Inspector City of Northampton From: Bruce Coldham Date: November 6, 2001 Cc: Jonathan Wright, Wright Builders Subject: Feasibility of creating a second-floor apartment Project Name: A–Z Feasibility Project #: 01-18 Total Pages: 2 1. INTRODUCTION: The existing single-story building was constructed in three stages over … years. The last (rear) phase completed in 1987. There is a total of 8,755 S.F. of primarily retail space. Theparcel is located at 57 King St. opposite the Hotel Northampton and extends back to the railway line. Totaling 26,500 S.F. in area, it is virtually entirely paved. The building is situated on the lot line (or within 24"±) along the northern boundary. Mechanical systems are served by units located on the roof, and one at least will need to be relocated to make way or the proposed apartment addition. 2. LAND USE & ZONING CONSIDERATIONS: There does not appear to be any inhibitions from a by-law standpoint. 3. BUILDING & RELATED CODE CONSIDERATIONS: 3.1 Construction type appears to be Type 3Bbased upon the existing conditions reported below: FRONT (Area 1) MIDDLE (Area 2) REAR (Area 3) FLOOR Concrete Slab on Grade Concrete Slab on Grade Concrete Slab on Grade PERIMETER SUPPORT 8” Load Bearing CMU (brick faced) 8” Load Bearing CMU 8” Load Bearing CMU INTERMEDIATE SUPPORT to be confirmed none none ROOF Steel Structure w/ Wood Deck Steel Truss w/ Steel Deck Steel Truss w/ Steel Deck 3.2 The primary use of the building is clearly Mercantile (M), though rear portions of the existing first floor may be considered as either Business (B) or light hazard Storage (S1). However, since Table 503 allows mercantile an area of 9,600 S.F. per floor for Construction Type 3B, an unseparated mixed use arrangement is feasible. The new second floor apartment is a R4 use. Under the provisions of (780 CMR 313.1.1) "a fire separation assembly is not required" between these or any other uses within the building. Therefore the existing steel bar joists presently forming the roof structure — and which would become the floor structure with the addition of a second floor apartment — can remain "unprotected". 3.3 The Mercantile (M) use allows for 2-story, 30' high structure to be constructed in Construction Type 3B (780 CMR Table 503). MEMO Coldham Architects Page 2 of 2 3.4 Fire protection & structure (780 CMR Table 602) - Encasing of the existing bar joists is not required in Construction Type 3B. 3.5 Non-combustibility of materials (780 CMR 604.1): — Combustible materials may be used for the floors, roof, interior partitions and interior load bearing elements in Type 3B. Non-combustible materials must be used for the exterior walls 3.6 Means of egress - Two means of egress (stairways) from the second floor apartment would be required. 3.7 Architectural access - not required for a single apartment unit. 3.8 Fire suppression (780 CMR 904.2) - Not required so long as the sum total of area is less than 12,000 S.F., which it would be. 3.10 Seismic loading (780 CMR …….): with 20% added area 50% of the lateral load requirement would have to be met 4. PRINCIPLE ISSUES: 4.1 The addition would require increasing the bearing capacity of the existing roof structure. This could likely be most effectively done by adding a line of support down the center of the rear portion of the building over which the apartment addition is intended to be located. This would also reduce the bearing on the existing perimeter walls and footings to the extent that the second floor loads are likely to be within the capacity of these existing elements 4.2 Seismic loading accommodation: Ryan Hellwig advises that meeting the 50% of the lateral load requirement can be more readily achieved at the rear (in the general location proposed for the addition), since there is an existing CMU block fire separation wall. But there may be further structural stiffening required, depending on the form and extent of the addition. 4.2 Reorganization of existing mechanical systems serving the lower floor - Consideration is to be given to the need to relocate the large unit in the vicinity of the proposed addition since this is likely to involve considerable expense (in the region of $50,000). The feasibility of the project therefore may hinge on our ability to create satisfactory plumbing space without needing to force the relocation of this piece of equipment. This, in turn, will depend upon our ability to create dwelling space that is sufficiently noise- and vibration-free. This may involve supporting the unit on columns to a footing independent of the roof structure.