Sustainable in time

Yesterday's post related to the water direction system that was implemented in my current home that channels water away from the foundation.  Listening to a lecture from another architect about the need for the world to be more sustainable and take advantage of the latest and newest technologies to do so (they were promoting smart electricity systems 'that you can control from anywhere!  Good grief, turn off the damned switch when you leave the room!)  But it got me to thinking.

Is sustainable just the new gadgets and doo dads that say 'we're green!' on them?  Or is there more to it?  By chance, I happened to read an article yesterday about using recycled materials to build houses.  The point the article made was the invested embodied energy (the amount of energy it takes to grow, harvest, shape and deliver a product to a building site equals the embodied energy)  was far less than the using a new piece of any material because it had already been used once.  This allows for the actual true cost of a material to be far less (you still have to move it unless you use it in its existing place).

So what I understood from these two seemingly separate items is that time and length of use matters.  The stone buildings in Europe have lasted centuries.  Yes, their initial cost is higher, but over time, this type of construction stands up and lasts while materials like wood and plaster tend to degrade and need to be replaced over time.  This difference in the length of time means that you would need to replace the wood structure far more often, possibly more than once.  And while the cost of each will most likely be less (in real money) than the original, over time, the cost will add up.  In addition, the additional materials to replace those that have failed will need to be recreated (embodied energy) repeatedly, taking up more resources (real and monetary). 

Thinking in terms of time and the ability of something to last is a factor that I believe is being overlooked in the rush to calculate the latest trend in sustainability.  Thinking generationally of what a place will need to last instead of just the 30 year window currently used for cost calculations and life cycle will lead to true sustainability. 

Likewise, creating details that extend the life of a material or structure, while not specifically labeled 'sustainable/green/environmentally friendly' can help to create an overall environment that is long term sustainable, even if it cannot be calculated by the standard du jour of the current building industry.

Just a thought.