The Queen's Gardens public toilets set the Nelson City Council back by more than $30,000 per square metre.
The final cost of the 15sqm toilet block, which contains two unisex toilets, one of which is accessible for the disabled and has a baby change table, came to $455,000. The cost per square metre was $30,333.
A new toilet block in Akaroa with seven unisex toilets and a male-only room with a toilet and four urinals cost just $175,000 more than the designer loos outside the Suter gallery, at $630,000.
Upgrades due for Tahunanui and Millers Acre facilities have an expected budget of $650,000 and $564,500 each, plus Government grants of $250,000 from the Tourism Infrastructure Fund towards each one.
According to last year's QV Costbuilder, the average construction cost of building a 150sqm house in Auckland in 2018 was $310,315, just over $2000 per square metre.
Nelson City Council group manager of infrastructure Alec Louverdis said the high cost of the build was due to a number of reasons.
"Construction projects in different regions of New Zealand are unique and each have their own sets of challenges, which are also affected by the local construction market. In this case, the design and build of this toilet block was neither straightforward nor standard," Louverdis said.
The contractors who built the loos, Scott Construction, made up $300,000 of the cost of the build. There were also structural design and supervision fees of $43,000.
The basalt stone cladding of the building needed specialist sub-contractors, and came in at $5200.
Arborist fees of $1300 were incurred as well thanks to the location of the gardens next door. Council resource and building consent fees added $5400 to the build, plus $2100 which went to a resource consent consultant.
"The location was a difficult construction site requiring work within the root protection zone of a heritage tree," Louverdis said.
"Special foundations were required to minimise the impact to both the California redwood tree and the original stone wall."
All of these costs brought the build up to $357,000, but the final cost had an additional 27 per cent, or $98,000, which went on architects fees for the design and supervision of the build.
The toilet was designed by architects firm Jerram Tocker Barron, which also designed the upgrade of the Suter Gallery and the public toilets in the 1903 Square.
Louverdis said the same architect was used to make sure the toilets complemented the location.
"The toilet is located in a high profile area beside both the Queens Gardens and the Suter Art Gallery," he said.
"The architect that designed the Suter was engaged to ensure that the toilets would complement these two important destinations. The architect was also involved in the supervision of the project which included daily site visits."
He said having architects design and supervise works was "not unusual" for council projects.
"[The] council engages professional consultants such as architects and engineers depending on the skillset required to successfully complete projects."
The long-awaited loos, which were tendered in February 2017, October 2017 and in February 2019, were finally completed in August and are now fully operational.
Other public toilets in Nelson due for upgrades include the Tahunanui Lions Playground toilets in Tahunanui, which will be replaced with a prefabricated building.
The new build will include six toilets, including one accessible toilet and one urinal, as well as unisex and family change rooms, three showers, external hand basins, a drinking fountain with bottle filler and foot wash for sand.
Millers Acre will also be upgraded to expand the facilities to seven toilets, one of which will be accessible for the disabled and have a baby-changing table, and one which will be a urinal only.
Both projects are expected to be completed in September 2020.
