Tag: statistics

This is an excerpt from a presentation delivered at the HWZ Third Wood Conference, 8 Feb 2013, CTICC, CapeTown

STATISTICS

Despite statistics such as 70% of the developed world’s population live in timber frame homes, and despite the resurgance in the popularity of timber homes in Europe in the last decade, my question is … will timber homes in South Africa remain with such a relatively miniscule share of the local market?

Numbers of timber homes built in SA were hard to find – the Local Authorities don’t collect data on the type of structure when plans are submitted; untill I remembered that one of the 2011 Census questions were: what type of material are the walls you house made of?  …and the census data is freely available.

According to the census, homes of a current value of R1m and upwards, which are not ‘bricks or cement block / concrete’, account for less than 0.38% of the total, with the figure for new houses built from 2000 to 2010 at just over 0.5%

TIMBER HOMES IN SA – A brief history up until now

The predecessor of the timber home in South Africa are the wood frame and iron clad homes, some imported in kit form from Europe, and others designed and built here – in the late 1800’s to early 1900’s. The most well known of these is the Smuts House, pre-fabricated in the UK and shipped to India, and later brought to South Africa where it was re-erected at Doornkloof for Jan Smuts in 1909.

An example of an iron clad timber frame building designed and built locally, is the Globe Tavern in Barbeton, which opened for business in 1887, designed by Arthur Hubert Halder.

Another example is the Millwood House, now a museum in Knysna. The house was originally built in Millwood during the ‘Gold Rush’ (very little Gold was found) in 1885, and was later relocated to Knysna, in sections, by ox-wagon, and re-constructed where St George’s Church Hall now stands. It was moved to it’s present site in 1910.

An example of a remaining timber clad building from that era is the Woodcutter’s Cottage, built in the 1880’s, on display at the George Museum.

After that era of timber frame building, iron clad timber frame buildings fell out of favour with the local authorities, and a period followed when they were all but completely outlawed. Many of our older title deeds still have clauses like ‘no corrugated iron’

Up to the 1950’s, the few timber buildings that were built were still being built of hardwoods. It was only around that time, with the introduction of preservative treatments, that softwoods such as Pine started gaining in popularity as a construction material, and was in the 1960’s that timber buildings were re-introduced as an alternative to brick and mortar.

Among the pioneers of this re-introduction of timber homes were Searles Homes in Great Brak River, who initially built timber frame homes to house the staff for their shoe factory. Others were Elgin Homes in Grabouw, and NST in Knysna, who introduced solid wood and log cabin building systems.

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While it’s evident that much of the design at the time was based on practicalities, an exception to this was the magnificent Bruynzeel House in Stellenbosch, with its hyperbolic paraboliod roof, designed in 1960 by Aart Bijl and built by Kees Bruynzeel, a Dutch wood merchant.

The majority of timber homes at the time, however, were relatively inexpensive holiday homes built along the Southern Cape coast, many of which were prefabricated.

In 1982, some members of the timber building industry got together to form the Timber Frame Builders Association, now called the Institute for Timber Frame Builders, which went a long way in achieving the recognition the quality timber buildings enjoy today, particularly with regards local authorities and lending institutions.

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If we look at a graph from the 2011 Census data showing the percentage of ‘non-brick & cement block’ houses since 1960, we see, however, that beyond the spike in the 1960’s (from close to zero % before that), little if no growth in percentage has occurred up until now.

This is while the percentage of timber buildings continues to increase year after year in many parts of the world, as people become more aware of the benefits of the systems available.

I can only guess that the perception of timber homes as a cheaper & less desirable alternative, perhaps still a result of it’s humble iron clad origins and later cost–effective prefab holiday house, still persist amongst many.

WHY TIMBER HOMES?

What is the fuss all about? Should we not just continue doing things here as we allways have, building most buildings out of bricks and mortar? What are the benefits?

For the Client: 

  1. Insulation – and therefore energy costs. Perhaps not yet such a huge issue, but with a potential electricity hike of around 16% for the next 5 years at this stage, it soon will be
  2. Natural Home – many clients chhose to build a timber home because they want a more natural home, that better fits into it’s environment. The same applies to beach resorts, and lodges in nature reserves
  3. Ease of construction and time to construct – it takes significantly less time to build a timber home than a similar brick & mortar home. It’s also easier to alter or add on to at a later stage – and a lot less messy.
  4. Difficult & Sensitive sites –  due to using relatively lightweight materials, several of my projects have been on difficult to access sites – where getting timber there is pretty easy compared to bricks. For sensitive sites timber construction also allows one to nestle right in between the existing vegetation with minimum disturbance. There are also cost savings on steeps sites, by using suspended floor structures

For the Environment: 

  1. Less energy used = less emissions  –  untill such time as our energy is produced from renewable resources, and not coal, any savings in energy are savings in harmfull emissions
  2. Low embodied energy – Of the various readily available raw materials for building, timber has by far the lowest embodied energy, and if grown in a sustainably managed plantation, is a truly renewable building resource. In terms of strength to weight, radiata pine, for example, has a strength to weight ratio 20 percent higher than structural steel, and more than four times that of unreinforced concrete in compression.
  3. Carbon sequestration – Trees absorb carbon as they grow and this carbon is locked away when the timber is used for construction – so the more timber you use instead of more energy and carbon costly materials such as masonry and concrete, the lower the carbon footprint of your home
  4. Treatment – most preservative treatments, which while providing the benefit prelonging the lifespan of timber indefinitely, have not been considered ideal from an enviromental perspective. This is changing with the introduction of new preservative treatments such as Tan E, which was recently accepted by Ecospecifier global

For the Architect / designer:

  1. Contemporary  – driven by technology everything around us is advancing in leaps and bounds. Think cellphones, tablets cars. Timber, along with other new lightweight building systems, allows us to be part of that technological revolution – rather than still building the way we were in the pre digital age. Technological advances in design software and digital fabrication technologies are now to allowing timber to be cut and fashioned to any shape you desire.
  2. Versatility – So thanks to the extreme versatility of timber, your timber home could be anything from a humble log cabin, to a grand Cape Cod style beach house, a sleek glazed all round clad post & beam house, or a digitally crafted open plan contemporary house with a freeform double curved roof.
  3. Building Regulations – Timber homes are included in the South African National Building Regulations standards, in SANS 10082, Timber Buildings. When built to these standards they also automatically achieve the standard required for registration with the National Home Builder Registration Council (NHBRC). They are also easily designed to meet the requirements of the new Energy Efficiency regulations SANS 10400 Part XA.

For the Builder:

  1. Passion – speak to any specialist timber builder and you are likely to find someone with a passion for their craft and for working with wood. Who would you rather have building your house?
  2. Precision & neatness– building with timber is a precise form of construction. Everything needs to be just right to work. For a builder and all involved it’s easier to monitor and see that everything is working according to plan. 

TIMBER BUILDING POLL with TIMBER IQ Magazine

In trying to understand, given the clear advantages and consistently small uptake, I recently set up a poll, along with Timber IQ Magazine, to help determine the attitudes towards timber homes in SA.

We had just short of 120 respondents, of which 29% were in the design or architecture field. What was most interesting was that 38% of the respondents had previously or currently still, live in a timber home.- and clearly wanted to share the advantages. And though I had not anticipated that such a large percentage of respondents would have lived in timber homes, their responses were of the most interest – particularly, because in each of the following cases, their responses, on average, rated higher than those who had not lived in a timber home

When asked to rate timber homes compared to brick, where an answer of 1 is much less, and a 5 far superior, in favor of timber, the average scores were as follows:

– Energy Efficiency                                     3.93    (3.80)

– the time it takes to build                           4.60    (4.41)

– maintenance requirements                        2.87    (2.70)

– Risk of fire                                               2.60    (2.35)

So, while at best the results could be said to be biased, as it was mostly people who like or have lived in timber homes who took time to do the survey, what I found relevant is that the comments by people who have lived in them showed that timber homes, even amongst this sample group, perform and are generally better than what the perception is.

CONCLUSION

So to answer the earlier question, will timber homes remain marginal in the built environment in SA? ….or will we see it grow as elsewhere?

My guess is that is that, as the pressure on resources increases, the efforts to slow down global warming escalate, energy costs escalate, along with the ever increasing technologies, there will be a shift. And possibly a large one.

And at the current low base of at best 0.5% of the market, even a 0.5% shift from brick to timber frame represents a 100% increase in demand for timber homes. And a still relatively small, compared to elsewhere, say 5% shift, represents a 1000% increase. I think the timber building industry may soon get very busy, and I invite more participants.