By Carter Holt Harvey
Ranui School in Waitakere City is the perfect example of an environmental approach to education. The new multi-purpose school hall - Te Kotuku Ki Ranui–was built to meet the guidelines developed by the New Zealand Green Building Council. By achieving the national specifications and compliance the project was awarded coveted Green Star points using hyONE® from the Futurebuild® LVL range (laminated veneer lumber).
Challenge:Although the initial plan was to use steel for the roof structure Carter Holt Harvey® Woodproducts was approached early on by contractor Naylor Love Construction Limited who were interested to see if timber could be used instead for a Green Star rating.
To meet the challenge CHH Woodproducts prepared a preliminary design for architect Andrew Buchanan of Brewer Davidson and engineer Steve Thorne of Thorne Dwyer Structures Ltd, proving a hyONE roof system was both structurally feasible and cost-effective.
Solution:The prelim design showed them that using Futurebuild LVL was cost-effective and would still fit with the architectural intent of the building. CHH Woodproducts also helped the engineer with specific structural engineering advice to enable them to complete the consent and construction drawings.
Steve Thorne says the build was reasonably challenging for them as the site was steep with quite a bit of work having to be done up above ground level to get a largely suspended flat concrete floor. He agreed that the rigid characteristics of hyONE were right to complete the job on top and felt the timber was more visually appealing than steel.
Similarly, all the teams involved in this project agree the building is architecturally stunning. It sits cleanly facing the rest of the school on one side and stands tall overlooking the valley on the other side. The warmth and colour of contrasting timber panels present a thoroughly contemporary design yet the stained Futurebuild LVL suggest an aged timber. Inside, the exposed beams span across the hall supporting the light, spacious interior.
Architect Andrew Buchanan believes that “the school whanau were an integral part of the design communication also” and helped create the end result.
“This was a unique project as each rafter was a different height and different width because the wall zigzags up the side,” explains Fabrication Manager Aaron Quinn of Carters Fabrication. “Instead of one or two templates for a basic building, there were 14 setups for 17 rafters equalling 34 pairs. Each component required an individual workshop drawing due to length and pitch changes and rebates required for steel posts and connections.”
Once on site the prefabricated rafters were lifted into place by mobile crane and manpower positioned on scaffolds. Project Manager Tom Ryder of Naylor Love Construction said the ease of working with hyONE and the additional benefits of working with a sustainable and renewable resource was in keeping with the environmental and cost issues. “We went down the Futurebuild LVL route because it was better for our Green Star rating. That was our intention.”
Result:If Ranui School is an example of green building then there is a lesson in choosing the right materials. In this case, hyONE ticked all the boxes for strength, aesthetics, and economics and, vitally, the environment.
Carter Holt Harvey (CHH) is one of New Zealand’s leading forest products companies, manufacturing and supplying timber, laminated veneer lumber (LVL), plywood and other building products to the New Zealand market. Carter Holt Harvey together with its legacy companies has been a feature of the Australasian timber industry for more than 150 years. Carter Holt Harvey is organised into four business units: Carter Holt Harvey Building Products (CHH Timber), Carter Holt Harvey Plywood (CHH Plywood), Carter Holt Harvey LVL (Futurebuild®LVL) and Carters Building Supplies.
CHH Timber is one of the largest and oldest producers of timber building products across New Zealand. Manufacturing timber across the Kawerau, Kinleith and Nelson Mill facilities, CHH Timber produces brands Laserframe®and Pinex®for use in structurally graded or outdoor timber applications.
CHH Plywood specialises in the manufacture and supply of both structural and non-structural plywood products, with familiar brands such as Ecoply®, Shadowclad®, Ecoply Barrier and Handiply®. These brands are suitable for a range of applications subject to proposed use including structural, exterior cladding, interior lining applications, DIY and packaging among some of the many uses. The brands are specified and used within the New Zealand construction industry by Architects, Builders and DIY professionals. Operating in New Zealand for over 30 years, CHH Plywood is one of the largest producers of plywood in New Zealand and manufactures from its central North Island site at Tokoroa.
Futurebuild LVL offers the largest range of LVL products within New Zealand, which are used in projects across Australasia. Manufacturing LVL in the Marsden Point plant, Futurebuild LVL produces brands hySPAN®, hyJOIST®, hyONE®, hy90®, hyCHORD®, truFORM®, hyPLANK®, edgeFORM®, and hyFRAME® building systems. Futurebuild LVL products are used in applications such as floor joists, beams, rafters, lintels, truss chords and purlins in construction of residential, commercial, industrial and rural buildings, subject to design verification.