Elephant Hill Estate and Winery
Scope of work
Part of a $40,000,000 development, the Winery and Viticulture Buildings house facilities for the processing of 400 tonnes of grapes. The Viticulture Building (500m2) consists of a machinery garage, workshop, chemical store, electrical switchboard room, water distribution room, office, staffroom and toilets and is used by the Viticulture team to look after the 25 hectares of grapes.
The Winery Building (2000m2) is divided into three parts:
Storage: Consisting of Plant Room, six temperature controlled cells for the storage of fruit and wine, and a separate tank room for the processing of boutique wines.
Process: This area consists of a Tank Room with room for up to 60 wine tanks, and the 600m2 underground basement for storage of second year barrels.
Retail/Office: This end of the building is three levels. On the first floor is the office space and laboratory, the ground floor houses a restaurant and the basement holds an observation room for private functions that looks into the second year barrel store.
Both buildings are similar construction: precast concrete wall panels to 2.4m, structural steel structure, and timber framed metal clad walls and roof.
Challenges
One of the biggest challenges was though construction methods were essentially commercial; a very high standard of finish was required. This meant that the precast panels and structural steel installed at the beginning of the contract not only needed to be of a high standard but also kept that way during the construction period. The precast panels were to be clear coated so any damage, no matter how well repaired, and would be visible. The paint system to the structural steel could only be achieved in factory conditions, so once again we had to prevent damage.
Another challenge was the Basement. This was 5m below ground with a 300mm thick floor, laid to falls. The walls, columns and ceiling were required to be “off the form” creating a rough sawn timber impression in the surface of the concrete. This also had to be protected during construction. The ceiling of the basement was vaulted with the floor above varying from 400mm thick at the top of the vault (this floor supported 20,000 litre wine tanks) to 1200mm thick at the bottom of the vault. There were many challenges in this ceiling including how to form the curve, how to support the weight of the concrete (1300 tonnes) and reinforcing (43 tonnes), and how to pour this amount of concrete (563m3) in just three pours. All of these challenges were resolved though consultation with our consultants, subcontractors and suppliers.
A feature of the restaurant is three “off the form” concrete walls. These walls are only 150mm wide so once reinforcing is placed there is not a lot of room for vibrating. Thoroughly vibrating these walls was essential because they are not only aesthetic, they are structural. Our concrete supplier came up with a self compacting concrete that enabled us to pour without vibrating. (We still applied external vibrating just in case). The results speak for themselves.
The cladding to both buildings was pre-aged copper, this is the first time this has been used in New Zealand although it is used a lot in Europe. This product is pre-finished and very expensive, so not only did it need to be protected from damage; it also had to be secure from theft.
Other challenges were logistic:
- Keeping the information and materials flowing to all the personnel on site (43 Alexander Construction staff and labour only contractors at its peak);
- Ensuring that the subcontractors were well informed and there when required;
- Controlling the flow of information from nine consultant teams and to almost 70 different subcontractors and suppliers (over 6000 items of correspondence).
- Having a very strong management team on site meant that all these challenges were met.
Highlights
One of the greatest highlights of this job was the unveiling of the vaulted ceiling. Seeing that we had achieved the very high standard of finish required was justification for all the planning and hard work that went into it. Other highlights were achieving the extremely high standard of finish that was required by the consultant team and being involved in what will no doubt become one of Hawke’s Bay’s most admired wineries.