Three of the original buildings of Barrhill plus the gatehouse at Wason's homestead were constructed of concrete, and they still exist to this day.

The four outer streets, one of which is the Rakaia Barrhill Methven Road, form a trapezoid with the longest side at 200 metres (660 ft).

[3] Apart from the main road, there are five avenues, each planted in its own species and named accordingly: oak, poplar, birch, lime, and sycamore.

Residents only noticed in 1975 when viewing an aerial photo that those trees form what appears to be the three circles of Trinity, with the two inner avenues possibly symbolising a crucifix.

He bought and sold land, and by 1882 Corwar was consolidated as a freehold estate of just over 5,000 acres (20 km2) with a large mansion overlooking the river, complete with gate lodge and gate-keeper.

[4] On the estate, Wason built a model village called Barrhill, with avenues forming a grid layout and a central market square.

Barrhill had 28 sections, including a post office, bakery, school, church, other facilities, and fifteen cottages were built.

[9] The post office opened in 1876[10] and in the same year, construction of the church began, and these buildings mark the beginning of Barrhill.

[4] A rural mail service was discussed for the Ashburton District in September 1924[14] and after the contracts were let in February 1925, the Barrhill post office was closed.

[2] It was their last project as a branch committee before the pending disestablishment of branch committees through the Heritage New Zealand Pouhere Taonga Bill, and they chose Barrhill to relaunch themselves as the Historic Places Mid Canterbury regional society as part of the unveiling of the historic panel.

The cement was landed in barrels on Kaitorete Spit, barged across Lake Ellesmere / Te Waihora, and then transported by dray overland and along the bed of the Rakaia River.

[21] St John's Church was mostly paid for by Wason,[22] and construction started in 1876, with the first service held on 8 July 1877 by the vicar of Ashburton, W. E.

[28][29] The other remaining 1870s concrete building is the gate house, located some distance away on the Rakaia Barrhill Methven Road.

Wason's homestead was at the end of a drive starting at this gate house, on a cliff top overlooking the Rakaia River.

[30] A plaque on the building states that it was reopened in March 1979 by the Prime Minister of the time, Robert Muldoon,[31] but his plane ran late and the opening ceremony was conducted by Colin McLachlan.

[4][34] New Zealand actress Tania Nolan, born in nearby Rakaia, lived in Barrhill for two years as a child.