Wood seems to be the obvious choice for the structural frame work in 1 & 2 family (residential) dwellings because of it's low cost, availability, and the familiarity of the work force with the skills required to work with wood.
So what about Commercial Construction? Many commercial structures are similar to residential, but I can think of three areas that change the most when comparing the needs for these buildings:
1. The Building Code – Although building codes for Residential construction are certainly more complex and complete in their reach than they have been, there aren’t as many trade offs in code requirements for various building materials as there are in the Commercial building codes. The advantage through the code development and lobbying process that goes with it is going towards materials other than wood as the code seems to limit commercial wood construction to smaller building sizes allowed and tighter sprinkler thresholds. Your own knowledge of the building code and easy access to a good Design Professional (ahem!) will allow you to better serve your building owners as you help them successfully navigate the choppy waters of today's building codes.
2. Average Sizes and Spans – the practical limits on span and size of wood structures continue to get pushed larger as we become smarter about how we use wood and combine it with other materials to achieve amazing things. I recently saw that a prominent wood connection manufacturer is currently testing a Seven (7!) story wood building in Japan for earthquake resistance. Also, realize that metal plate connected trusses are being used to clear span 60’, 80’, even 100’+ today by using dimensional lumber with Metal Plate Connectors. Compare these spans to what was possible with traditional rafters and ridge beams or rafters and collar ties that was the norm 2 generations ago and is still used in many residential buildings today. The irony is that the average size of available wood coming out of our forests is shrinking, but producers of engineered products are making stronger, straighter, and more reliable wood building materials out of these raw materials. This progress allows spans in wood construction today at the higher commercial floor and roof load requirements (of the building code, see #1) that would not be conceivable with the wood products available just a decade or two ago. Engineered use of Wood is making a difference!
3. Construction Budget – Typically higher for Commercial vs. Residential, however I think that this generalization has reversed its trend over the past 20 years as many new houses over the last decade have still been built much larger than needed (“McMansions”) while many businesses and multi-family developments are looking to build with the minimum capital requirement because the financial conditions reward the projects with the best cash flow, or return on investment. Advantage in the cost department: Wood!
1. The Building Code – Although building codes for Residential construction are certainly more complex and complete in their reach than they have been, there aren’t as many trade offs in code requirements for various building materials as there are in the Commercial building codes. The advantage through the code development and lobbying process that goes with it is going towards materials other than wood as the code seems to limit commercial wood construction to smaller building sizes allowed and tighter sprinkler thresholds. Your own knowledge of the building code and easy access to a good Design Professional (ahem!) will allow you to better serve your building owners as you help them successfully navigate the choppy waters of today's building codes.
2. Average Sizes and Spans – the practical limits on span and size of wood structures continue to get pushed larger as we become smarter about how we use wood and combine it with other materials to achieve amazing things. I recently saw that a prominent wood connection manufacturer is currently testing a Seven (7!) story wood building in Japan for earthquake resistance. Also, realize that metal plate connected trusses are being used to clear span 60’, 80’, even 100’+ today by using dimensional lumber with Metal Plate Connectors. Compare these spans to what was possible with traditional rafters and ridge beams or rafters and collar ties that was the norm 2 generations ago and is still used in many residential buildings today. The irony is that the average size of available wood coming out of our forests is shrinking, but producers of engineered products are making stronger, straighter, and more reliable wood building materials out of these raw materials. This progress allows spans in wood construction today at the higher commercial floor and roof load requirements (of the building code, see #1) that would not be conceivable with the wood products available just a decade or two ago. Engineered use of Wood is making a difference!
3. Construction Budget – Typically higher for Commercial vs. Residential, however I think that this generalization has reversed its trend over the past 20 years as many new houses over the last decade have still been built much larger than needed (“McMansions”) while many businesses and multi-family developments are looking to build with the minimum capital requirement because the financial conditions reward the projects with the best cash flow, or return on investment. Advantage in the cost department: Wood!
There is another issue where wood has a clear advantage when comparing building materials and that is overall sustainability. The issue is quite simple but has been made complex in an by various political and special interest groups lately.
More about sustainability soon, but for now keep in mind, wood is good!
- Wood uses a very efficient and natural form of solar energy for its production (Photosynthesis!)... very little energy is required to harvest and process it
- Wood can be naturally grown and replaced faster than it's rate of consumption without sacrificing the environment in the process (now THAT'S sustainable!)
- Wood is easy to recycle or reuse or compost
- Wood buildings, when properly constructed, can last as long as any other material used in construction today.
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