The Upper School English and History annex is located on North Maple Avenue, a short walk from the main Upper School facility, occupying the former Preschool campus.

Also found at the North Maple facility is the Brunswick Career Center, which puts an emphasis on preparing recent alumni for the workforce.

Additionally, Brunswick owns a boat house, the Falco Rowing Center, located on River Road, just a ten-minute drive from the Upper School campus.

[8][better source needed] The connection between Greenwich Academy and Brunswick dates back to the school's founding.

The founder of Brunswick had been previously employed as a teacher at Greenwich Academy, which was then a co-educational secondary school.