Porta potty for a 6-month garage build. Winter is coming.

Tell the rental company you need winter service for a standard portable toilet. Weekly service does not automatically include winterization; you must request it. The rental company adds a brine or non-toxic antifreeze solution to the holding tank during the service visit to prevent the waste from freezing solid and cracking the tank. They will handle this when you specify the unit will be exposed to freezing temperatures.

Your setup is good. The asphalt driveway provides level ground, and the truck access is clear, which is what the operator needs. For a crew of four working five days a week, one standard unit meets the OSHA 1926.51 minimum for construction sites, which requires one toilet for 20 or fewer workers. No alcohol or food means less mess, so weekly service should be sufficient unless the crew reports issues. In winter, if the unit gets heavy use from wet boots tracking in mud, you might need more frequent cleaning, but the service frequency is usually adequate.

The rental invoice should show the monthly rental rate, the delivery fee, the service visit charge, and any winterization add-on. Confirm the antifreeze is formaldehyde-free, which is standard now because wastewater treatment plants restrict formaldehyde. Your crew will have a usable toilet all winter if you arrange this.