Thursday, January 31, 2013

demolition action

I'm in the business of creating things, buildings mostly but I occasionally create urban plans and developments.  If I am successful I am creating a better way of living; if not then I have just handed out fifty years of misery (that's the intended life span of most buildings these days).  I believe in sustainability, not just through environmentally friendly building designs but also by creating a building that is enjoyable enough to keep.  I've seen some so-called green buildings that are so criminally ugly that it would be a miracle if they lasted even ten years.

These days it is rare to build on "virgin" land.  I'm pretty happy about that because I like to resist sprawl.  It does happen, even in Hong Kong where you would think that everything has been built up already, and it presents a serious ethical issue to me.  I struggled a lot in my previous job with a project to develop a rural and history rich area in the New Territories into a transportation hub/new town.  Hong Kong is growing and there is a great need for (somewhat) affordable housing but the cost is that you are demolishing another way of life to make room for current needs.

Thankfully most architecture in Hong Kong involves redevelopment.  Something is demolished and replaced by another version that of itself on steroids.  Everyone wants to work in a high profile office building.  At the same time, the big, shiny, flashy office building needs to have an environmental rating.  We used to go by the US LEED rating system but it wasn't designed for places like Hong Kong and some of the local LEED rated buildings have podiums that block out light and ventilation to all the buildings behind them.  SARS anyone?  I am grateful to all of the environmental professionals who developed the Hong Kong BEAM system, which won't be handing out any plaques to buildings that overshadow the neighborhood.

Another wonderful consideration for a BEAM rating is how a project treats construction waste.  You can't just flatten an existing building and then start the rating process; your demolition practices are being graded as well.  In a place like Hong Kong where 20% of all waste intake is from construction materials, the ability to reuse and recycle demolition debris makes a big difference.

The other day I saw a video of Taisei Corporation's demolition process, called Taisei’s Ecological Reproduction System (TECOREP).  It focuses on disassembly rather than demolition and being Japanese, it is efficient, quiet, clean, and kinda perky.

The structure’s top floors are enclosed into a cap with temporary columns and jacks, and then the entire floor is dismantled.  This process is repeated floor by floor until the entire building is taken apart.  As demolition workers begin to disassemble the building from within, they use interior cranes to lower materials. After dismantling an entire floor, the jacks quietly lower the “cap” and the process is repeated.  According to TECOREP, the process also reduced noise levels by 17 to 23 decibels and cuts dust levels by as much as 90 percent.


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