The Northern Guardhouse was built for the military guard and was used as both his home and office while the Southern Guardhouse was the local police precinct. It is a single story rectangular plan, rendered masonry building with a hipped slate roof and a verandah to the front façade. The verandah has flagstone floors and a corrugated iron roof supported by six decorative cast iron Victorian columns.

Although looking very similar from the exterior and were of comparable size, the interior layout was quite different. The main door of the Northern Guardhouse opened into a large Guardroom with adjoining cloak room, pantry and bathroom with two bedrooms and a small living room on the ground floor level. The lower level housed the kitchen and wash house and opened onto the lower courtyard. In both guardhouses the working areas were separate from the living areas and there was no connecting doors between the two. The Northern Guardhouse was simply decorated and furnished with one wooden guard bed and a deal top table.

During the building of the Mint complex the guard duties were formed from a detachment of the Royal Engineers who provided security and undertook sentry duties. After a few years these were replaced by the local Corps of Artillery but in 1879 the administrative staff had to take on these duties and were then armed for the task with pistols. The building is noted on later maps as the caretaker’s residence and it was used as a residence for many years although was left empty for several years before coming under the management of the Mint Inc.

The building underwent extensive restoration in 1998-9 and a separate toilet facility was built at that time to enable the Guardhouse to be used as a restaurant and bar. The Mint Bar and Bistro has traded successfully for many years and is a popular meeting place for the legal and commercial people of the district. The use of temporary shelter opening from the verandah and exterior heating mean the outside areas can be used all year round to extend the quite small interior spaces.