NZFFA Member Blogs
Member Blogs
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Brian Cox's Blog
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Chris Perley's Blog
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Dean Satchell's blog
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Denis Hocking's blog
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Dennis Neilson's blog
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Eric Cairn's Blog
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Hamish Levack's Blog
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Howard Moore's blog
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Ian Brennon's blog
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Ian Brown's Blog
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Jeff Tombleson's blog
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John Ellegard's blog
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John Fairweather's blog
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John Purey-Cust Ponders
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Murray Grant's Blog
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Nick Ledgard's Blog
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Rik Deaton's Blog
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Roger May's Blog
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School of Forestry blog
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Shem Kerr's blog
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Vaughan Kearns blog
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Wink Sutton's Blog
Recent blogs:
Wooden windows – a missed opportunity?
Wink Sutton's BlogThursday, August 30, 2012
Our house in Rotorua was built in 1969. It has single pane glass windows in wooden frames. Although winter condensation is only a minor problem, when it does occur it is confined to the glass. Our holiday home was built in 2009. It has aluminium frame windows with, by regulation, double glazing. There is still the occasional winter condensation but, in contrast to our Rotorua home, it now occurs on the window frames and not the glass.
Compared with wood, aluminium easily transfers heat and cold but eliminates the need to repaint or re-stain. Aluminium is also less likely to distort in later life. If wood could be permanently finished, and this eliminated the need to repaint or re-stain, the market for wood, especially for clears from our pruned radiata, could be enhanced.
In the mid 1990s I visited a factory in Sweden making impressive wooden framed triple glazed windows. The market for these windows was high-rise buildings. The windows were expensive but were well designed and were of a very high quality. They were very flexible as they could be opened both vertically and horizontally, obviously not at the same time.
Most impressive of all was that the windows were guaranteed for at least 50 years. All the wooden components were painted with what looked like an epoxy finish. Understandably I was not told what was used but I was informed that it contained a hardener and that the finish must be applied within one hour of mixing. A condition of the 50 year warranty was that the seal on the wooden window frames must remain unbroken. The window was supplied with a clamping structure so that the window could be permanently fixed in place without the need for any nails or screws.
I have long thought that New Zealand has missed a wonderful opportunity. We should concentrate on wood’s advantages, such as its low thermal conductivity, and develop ways to overcome any disadvantage, such as a permanent finish which eliminates the need to repaint or re-stain.
Such a development requires innovative thinking, a focussed and intensive research effort, excellent design, a great deal of capital and a major global marketing campaign. However, the financial rewards could be impressive. Is such thinking now beyond us? What other opportunities have we missed?
Wooden skyscrapers are wonderful, but...
Wink Sutton's BlogWednesday, May 30, 2012
Google the ‘the world’s tallest building’ and responses include proposals for a 16 to 17 storey building in Norway and for the Creative Renewable Energy and Efficiency group’s plan for a 30 storey building in Austria. Google ‘Vancouver wooden skyscraper’ and the response includes architect Michael Green’s proposal for a 30 storey wooden skyscraper in Vancouver, British Columbia.
As wood suppliers we should welcome proposals that finally recognise the major environmental advantages of wood, such as its low energy requirements, sustainability, carbon sequestration and earthquake benefits. As many of us have advocated for years for the environmental advantages of using wood we must ask why have wood’s advantages taken so long to be accepted?
The promoters of wooden structures are architects and engineers, professions that have little or no understanding of forestry. If there is a move to build large wooden structures we are looking at a quantum increase in wood demand. We would almost certainly see a reversal of the long-term decline in per capita consumption of industrial wood.
The first record of global wood consumption was in 1920. Since 1920 the wood harvest has doubled, but over that same period the global population has increased almost four-fold, so the per capita consumption has almost halved in the last 90 years.
Several projections of the future global wood supply suggest that the global wood harvest could increase slightly over the next 20 years. However, the forest industry could not supply the quantum increase in wood demand that will almost certainly result if there is a trend towards large wooden buildings. Other than those just grown on short rotations for pulping or reconstituted wood products, trees require at least two decades before they are large enough for conversion.
Almost all the trees that will be harvested in the next 20 years are already growing which is why future wood harvests can be so confidently predicted. Even if there is a large increase in the establishment of plantations these will not be available for harvest for at least the next 20 years.
Adding to the world problems is that a significant increase in plantations will require a massive investment as tree growing is the most capital intensive industry there is. Governments have no interest in long-term investments such as plantation establishment. The private sector tends to buy plantations which already exist rather than invest in the creation of new plantations. In contrast, the increased production of steel and cement requires less capital and more importantly only one to four years before production can start.
Wooden skyscrapers are a wonderful development, but more consideration should be given to where the required wood might come from.
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Disclaimer: Personal views expressed in this blog are those of the writers and do not necessarily represent those of the NZ Farm Forestry Association.

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