The three-storey building, designed by architect Robert Mason, was erected in 1910 and is an example of Classical Revival architecture, with its two large Corinthian columns and pilasters.

The interior of the building has been treated with complete renovations since 1994, including an overhaul of its HVAC system and the addition of a wheelchair ramp.

Recently a visible storage gallery was built in front of the annex to display vehicles and other large items in the museum's collection.

The second floor gallery is known as the James Murphy Room and is dedicated to meetings and programming, such as birthday parties and themed march & summer break camps for children.

The archives has 130 metres of linear records, 1900 maps and plans, 150,000 photographic images and a 2200 volume library.