Waitomo Caves Visitor Centre Hero

Waitomo Glowworm Caves Visitor Centre: a world-class facility

The Waitomo Caves are a popular tourist attraction located near Otorohanga in the Central North Island Region. In 2005, fire struck the original Waitomo Glowworm Caves Visitor Centre, destroying the building. It was a huge blow to the community who rallied together to keep the caves open for everyone to enjoy. Hawkins was engaged to construct a new, more extensive and modern visitor centre.

Tourism Holdings Limited’s (THL) aim:

  • To build a new, more extensive and modern visitor centre showcasing how engineering, the environment and local culture can be fused together in harmony and enhancing people’s overall experience in the region.

What we did:

We constructed this primarily timber-framed structure comprising three levels, which incorporates:

  • offices
  • a retail area
  • a restaurant with a full commercial kitchen
  • ticketing area
  • exhibition centre
  • various amenities
  • a lift which provides access to each level.

The entire building is covered by a large, timber-framed, curved ETFE canopy structure, the first of its kind in New Zealand. As a result of this never having been attempted before, we had to pioneer a strategy for its construction. To do so we developed a prototype in conjunction with the engineer and architect, prior to construction, to examine in detail how best to go about it.

The canopy structure comprises a series of curved, laminated timber beams running in opposite directions and crossing over at nodal points. For the structure to work, the curved beams had to be incredibly accurately manufactured. The roof is completed with translucent inflatable ETFE pillows, which provide a watertight covering and follow the curve of the canopy.

The visitor centre generates its own water supply. Canopy rainwater is discharged via a landscaped swale, with peak overflow to the river. The water supply is taken from the river after local filtration and treatment. The centre also uses water efficient sanitary fixtures.

Unique challenges:

The project team had to manage and construct this complex structure on a steep and confined site, in often less than ideal weather conditions, to a tight programme, while ensuring the facility remained operational.

  • After clearing the steeply sloping site, which was immersed in vegetation and large trees, it was benched in order to create a base for the three levels. MSE soil-retaining walls were constructed at each level. The bulk earthworks were delayed by wet weather but we managed to accelerate the programme to ensure we met the strict completion deadline.
  • We had to put strict environmental procedures in place as a stream ran across the base of the site. We constructed a permanent swale drain, running the entire length of the site, early on to provide drainage at the low end. This discharged into a large soak hole and was temporarily covered with filter cloth to prevent sediment blockage. Various temporary trenches, earth bunds, soakage pits and silt fences were also constructed to control run off.
  • The Waitomo Caves are an international tourist attraction and had to remain operational throughout construction. We were able to ensure that day-to-day operations and public safety were maintained at all times by continual co-ordination with the operations staff, carefully placed hoardings and fencing and the construction of various temporary stair structures and tracks. We set up temporary amenities using a Portacom, which was dressed up to provide a visually acceptable façade to the public.
  • In order to meet the extremely tight construction programme, the installation of internal finishings had to commence before the building was complete or watertight. Temporary waterproofing membranes were installed over the exposed floors above each level to create a waterproof environment.
  • As a result of the tightly confined nature of the site, construction was carefully staged to ensure the availability of adequate access for cranes and other heavy machinery at essential stages of the build. The canopy was constructed from the innermost end of the site to the outer. Appropriate traffic control measures were put in place and maintained at all times at the front of the site, which was in line with the road.

The outcome:

The new Waitomo Glowworm Caves Visitor Centre is reborn from the ashes. It showcases how engineering, the environment and local culture can be fused together in harmony and enhances the experience of visiting the region.

The project was handed over to THL in May 2010.