5.9.Japan-2-detail-b total cost of ownership Highlights Relevant to Sustainable Design:

Look for component modularity and longevity.

This sketch illustrates a diagonal carpentry detail used to connect the lower part of the post to the one above. This detail is used so that about twenty years after construction, when the lower post rots and decays from weather, the bottom two-foot piece can be removed and replaced. In modern construction, we typically choose to save time by not cutting such a joint for the future and instead use pressure-treated lumber to combat the problem. Of course, we have had to regulate and invent a way to keep the chemical by-products of the pressure-treated process from killing river fish and contaminating groundwater.

The component modularity and long twenty-year cycle of replacement reminds me of the long twenty-year life of the LED lights. The initial LED investment is higher than a fluorescent tube or compact fluorescent lights (CFL), and the equivalent of pressure-treated chemicals in the wood is the toxic mercury in the fluorescent tubes and CFLs. Just as we have to manage the toxins in the wood, we have to manage under controlled disposal the hazardous mercury in the fluorescents. By contrast, the modularity of LEDs, with an external driver, allows us to replace only the part that is damaged over time and not the whole product.

Life cycle cost and environmental impact analysis often shed light on the winners that are not always the least expensive to start but the lowest total cost of ownership over time. This is the difference between return on investment (ROI) as a sprint and lowest total cost of ownership (TCO) as a marathon.

7.19.USA-5-detail.c relative to total cost of ownership

Here is a comparison to a strategy at a Pennsylvania farmhouse to keep the water from damaging the lower portion of the wood on a porch post. The approach also takes into account the lifetime total cost of ownership.

This American detail includes a metal “pin” that elevates the wood, so that when it rains the wood does not get wet and whisk up the water. Remember that wood is not only porous, but the internal structure is like a set of multiple tiny straws that by natural design draws water up from the ground to feed the leaves in the upper branches. This man-made design simply keeps the rainwater from damaging the bottom of the post, and it eliminates the need for harmful chemical treatments such as pressure-treated lumber.


total cost of ownership, porch post detail

Author and illustrator: Charlie Szoradi is an architect, inventor, and the CEO of Independence LED Lighting. He writes about many other topics related to total cost of ownership through his extensive travels around the world.

If you have found this posting online, it is an excerpt from Mr. Szoradi’s book Learn from Looking that served as the inspiring seed content for this drawing share resource. For additional drawings and insights on total cost of ownership, we hope that you enjoy exploring LearnfromLooking.com. You can search via general terms such as sustainability as well as narrower terms such as total cost of ownership.