To finish a 40' off-grid shipping container workshop, start with insulation to regulate temperature and enhance energy efficiency.

Install solar panels with a battery bank and inverter for power. Ensure adequate ventilation with windows or vents.

Fit the interior with workbenches, shelving, and essential fixtures. Set up plumbing if needed, using rainwater collection or external sources.

Finish with durable wall and floor materials, and protect the exterior with weather-resistant paint. These steps will create a functional, self-sufficient workspace.