Code of Massachusetts Regulations
225 CMR - DEPARTMENT OF ENERGY RESOURCES
Title 225 CMR 22.00 - Massachusetts Stretch Code and Specialized Code 213 For Low-rise Residential
Chapter 5 - [RE] EXISTING BUILDINGS
Section RC105 - SOLAR-ROOF ZONE

RC105.1 General. New detached one- and two-family dwellings, and townhouses with not less than 600 square feet (55.74 m2) of roof area oriented between 110 degrees and 270 degrees of true north shall comply with Sections RC105.2 through RC 105.10.

Exception: A building where all areas of the roof that would otherwise meet the requirements of Section RC105 are in full or partial shade for more than 70% of daylight hours annually.

RC105.2 Construction document requirements for solar- zone. Construction documents shall indicate the solar zone.

RC105.3 Solar Zone Area. The total solar zone area shall be not less than 300 square feet (27.87 m2) exclusive of mandatory access or setback areas as required by the MA Fire Code. New townhouses three stories or less in height above grade plane and with a total floor area less than or equal to 2,000 square feet (185.8 m2) per dwelling unit shall have a solar zone area of not less than 150 square feet (13.94 m2). The solar zone shall be composed of areas not less than five feet (1524 mm) in width and not less than 80 square feet (7.44 m2) exclusive of access or setback areas as required by the MA Fire Code.

RC105.4 Obstructions. Solar zones shall be free from obstructions, including but not limited to vents, chimneys, and roof-mounted equipment.

RC105.5 Shading. The solar zone shall be set back from any existing or new permanently affixed object on the building or site that is located south, east or west of the solar zone a distance not less than two times the object's height above the nearest point on the roof surface. Such objects include, but are not limited to, taller portions of the building itself, parapets, chimneys, antennas, signage, rooftop equipment, trees and roof plantings.

RC105.6 Capped Roof Penetration Sleeve. A capped roof penetration sleeve shall be provided adjacent to a solar zone located on a roof slope of not greater than one unit vertical in 12 units horizontal (8% slope). The capped roof penetration sleeve shall be sized to accommodate photovoltaic system conduit and shall have an inside diameter of not less than 1% inches (32 mm).

RC105.7 Roof Load Documentation. The structural design loads for roof dead load and roof live load shall be clearly indicated on the construction documents.

RC105.8 Interconnection Pathway. Construction documents shall indicate pathways for routing of conduit or plumbing from the solar-ready zone to the electrical service panel or service hot water system.

RC105.9 Electrical Service Reserved Space. The main electrical service panel shall have space to allow installation of a dual pole circuit breaker for solar electric installation.

RC105.10 Construction Documentation Certificate. A permanent certificate, indicating the solar PV system size in AC and DC KW and or solar thermal size in KW equivalent and other requirements of this section, shall be posted near the electrical distribution panel, water heater or other conspicuous location by the builder or registered design professional.