South Mountain Company

West Tisbury, Massachusetts, United States

SolarCooperative

Founded 197551-200 employees

Profile last updated: August 15, 2026

About

Founded in 1975, South Mountain Company is a cooperative headquartered in West Tisbury, United States with approximately 51-200 employees specializing in Solar.

South Mountain Company is a worker-owned cooperative based on Martha's Vineyard that has operated for over 50 years. The company provides integrated architecture, interior design, construction, and solar energy services. They specialize in custom home design, sustainable building practices, and residential solar installation. Known for their commitment to quality craftsmanship, environmental stewardship, and affordable housing advocacy, South Mountain combines traditional carpentry with contemporary design and renewable energy solutions. The company operates as a B Corporation and is dedicated to creating lasting value through long-term thinking, shared prosperity, and deep environmental care.

Headquarters

West Tisbury, United States

Founded

1975

Employees

51-200

Company type

Cooperative

Focus areas

solar installationarchitectureconstructionsustainable designworker-owned cooperativeaffordable housingMartha's VineyardB Corporation

Products & services

Business models

B2BB2CEPC

Value chain

DevelopmentEngineeringConstructionO&MConsulting

Service areas (1)

Martha's Vineyard Solar Installation and Planning
End-to-end solar energy planning and installation services focused on clean energy independence and sustainable sources

Locations

Headquarters

Red Arrow Road 15, 02575, West Tisbury, Massachusetts, United States

Operating locations (1)

West Tisbury, Massachusetts, United States

Service regions

United States

Projects

West Tisbury Pocket Neighborhood

OperationalRooftop solar PV with residential homes

Eight single-family eco-friendly houses within a 3.5-acre building envelope on 8 acres, designed with high-performance building standards and solar electric systems. LEED platinum certified, approaching net-zero energy.

West Tisbury, United StatesCompleted: 2019-01-01