[3] James Harper and his wife Mary bought his first block of land in Berrima in 1832 on which he built the Surveyor General Inn in 1834, becoming its licensee in 1835.

The National Trust thinks that the house was built from the pattern book of a Georgian townhouse, which was common in the colony.

Harper's widow Mary married James McDermott and moved into the Surveyor-General Inn, which her family owned until the 1920s.

[3] In 1898 the priest was relocated to Moss Vale and the house was vacant until four Sisters of the Daughters of Our Lady of the Sacred Heart, who had opened a school in Berrima, used it as a convent from 1903 to 1909.

The original detached brick kitchen had collapsed and a fuel stove had been installed in the room to the right of the front door.

A small corrugated iron shed near the back door served as a laundry and bathroom with water being drawn from the well by a rope and bucket.

The firm of the heritage architects Clive Lucas Stapleton and Partners undertook the seven-year restoration and Harper's Mansion was opened to the public in 1985.

In 2011 the eastern main bed of perennials was replaced with heritage roses, many of which would have entered the commercial market before the middle of the 19th century.

[3] There is remains of the squared cottage garden in front of the house with axial path and evidence of fence and gatepost.

[3] The fact that the house, with exception of the removal of the verandah, survives virtually unaltered adds to its significance.

[9][3] Harper's Mansion is one of the most archetypal colonial Georgian houses surviving in NSW and a significant element in the historic town of Berrima.

[3] Harper's Mansion was listed on the New South Wales State Heritage Register on 1 March 2002 having satisfied the following criteria.

[3] The place is important in demonstrating aesthetic characteristics and/or a high degree of creative or technical achievement in New South Wales.

The aesthetic significance of Harper's Mansion is extremely important in the construction and recognition of Berrima as a heritage town.

Harper's Mansion contains social significance as it represents a homestead built by the middle class colonialists during the first half of the nineteenth century.

Although the house was built for James Harper and his family, the property had a 120-year association with Roman Catholic Church mainly as a presbytery.