Antrim House is a 1905 Category 1 heritage building in Wellington designed by Thomas Turnbull and Sons as a family home for prominent businessman Robert Hannah. Following use as a private hotel and government hostel in the years after Robert’s death, the building has been home to The National Office of Heritage New Zealand Pouhere Taonga since 1981. In 2025, the building underwent a much-needed roof replacement. Roofing Industries’ True Oak profile provided the heritage look required while ensuring long-term high performance.

“The initial key driver of this project was the replacement of the existing corrugated steel roof,” explains Jamie Jacobs, Heritage New Zealand. “The roof was last replaced in 1969-70 when the building functioned as a public service employee hostel. The roof installation was not done very well originally; deficiencies in the original detailing of the roof were not corrected, and the roofing material had reached the end of its serviceable life some years ago. Consequently, we had increasing numbers of repairs required to maintain the weathertightness of the house.” 

The roof renovation provided an opportunity to improve rainwater disposal capacity — correcting existing design weaknesses and ensuring the building is better equipped for climate change and increasing localised downpours. The project also expanded to include changes to the roof and attic structure and removal of three masonry chimneys, which increased the seismic resilience of the building.

When considering the new roofing material for Antrim House, preserving the look of the original roofing was crucial. Durability and low maintenance were also key to ensure the roof would stand the test of time. “The main thing was to match the corrugation profile of the existing roof as closely as possible,” says Jamie. “The existing long-run corrugated steel roof, in the traditional high corrugated profile, was replaced in Colorcote Alumigard long-run corrugate sheeting, in True Oak profile.“

Roofing Industries’ 0.90mm aluminium True Oak profile features distinctive shadowlines and deep curves that replicate the look of the traditional corrugate roofing common on many of New Zealand’s older buildings. This has made it a popular choice for heritage projects such as Antrim House. 

“The profile has the correct “old school” look in terms of profile that is important for an early-20th century building and for a Category 1 historic place,” says Jamie. “Modern 18mm high corrugate is much too flat in profile visually to sit comfortably with such an architecturally strong heritage building, and would not have looked nearly as authentic.”

The True Oak profile was specified in Colorcote Alumigard in Gull Grey — a system that uses a marine grade aluminium alloy substrate, providing exceptional performance in harsh environments. “Colorcote Alumigard has been selected because it matched the texture and appearance of the existing roof and offered more durability,” says Jamie. “It was materially more robust and durable than coated steel, and offered greater ease in maintenance over its lifetime. It also provided for better drainage capacity overall.”

Installation of the new roof was completed by roofing installers Classic Metal. This was followed by repair and repainting of the full exterior of the building for the first time since 1905. The Gull Grey colour of the roof harmonises well with the four-colour palette of the new paint scheme.

This sensitive renovation of Antrim House has enhanced the building’s historic character without compromising on performance. The new roof is durable, low maintenance and better prepared for harsh weather events, all while preserving the heritage aesthetic of the building. 

“The functionality and aesthetics of the roof are wonderful,” says Jamie. “The pale grey roof tones well with the predominantly green colouring of the new paint, all of which gives the house a much greater sense of lightness overall. Both phases of the project are exemplars of heritage stewardship and will functionally serve Antrim House and Heritage New Zealand Pouhere Taonga for decades to come.”