Resource efficiency, construction and
the circular economy
Alliance for Sustainable Building Products: 27th February 2013
John Dowling
Sustainability Manager, British Constructional Steelwork Association
Mineral reserves
We know very little about real reserves
and there is much to be discovered
This gives an indication of the reserves
of discovered iron ore at current
consumption
Latest best estimates indicate 500
years supply of iron ore
The steel cycle in construction
Product
manufacture
Raw
materials
acquisition
Steel
manufacture
Intermediate
processing
Construction
Disposal
Demolition
In
use
Steel production worldwide
•  Steel can be manufactured using 100% scrap or from a
mixture of scrap and iron ore
•  World steel production is approximately 1500 million tonnes.
•  Of this, approximately a third is from recycled scrap.
•  The scrap capture infrastructure works at over 80%
efficiency.
•  Thicker, heavier products are more likely to be made from the
scrap route and light gauge material is more likely to be
made from the iron ore route.
WARNING
Never specify metals on the basis of recycled content. It
will not improve recycling rates and may be counterproductive
Recycling and reuse rates for steel in
construction
Structural
Sections
Purlins &
rails
Cladding
Decking
Rebar
Internal
Non-structural
Steel
Recycling %
86
89
79
79
91
85
Reuse %
13
10
15
6
1
2
Landfill %
1
1
6
15
8
13
There is nothing new about reusing
structural steel
Honda in Swindon: dismantled, stored and
rebuilt
Prologis Park, Heathrow
•  Design for disassembly
and re-use
•  Clear identification of each
piece
•  Result: 80% re-usable
There is nothing technically difficult
about reusing structural steel.
• So why isn’t it done more often?
• Difficulty in guaranteeing properties?
• Who will take responsibility?
• Difficulty in dismantling structures (time)?
• The nature of the demolition industry?
• Lack of critical mass?
Implications of reuse
•  Potential move away from composite construction in
some cases.
•  Changes in deconstruction/demolition practice.
•  Bolted rather than welded assemblies.
The onus is on the construction sector
to provide buildings in a manner which:
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Minimises resource use
Minimises lifetime cost and resource burdens
Minimises energy use
Guarantees long and useful life.
Features of buildings of the future
•  Low operational energy.
•  Flexible and adaptable to maximise life span and future
proof the building.
•  Design for easy refurbishment and renovation.
•  Use materials which can be easily recovered and which
have high recycling and reuse potential.
•  Design for recovery, re-use and demountability at end of
life.
•  Maximise the amount of work done off-site.
•  Use construction materials and methods which minimise
waste.
National Trust HQ, Swindon
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•
•
•
•
•
•
•
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BREEAM excellent
Brownfield development
Naturally ventilated
Quick construction
Long-span flexibility
Shallow structural zones
Lighter foundations
Thermal mass
Heat recovery
Photovoltaics
Manchester Civil Justice Centre
•
•
•
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BREEAM excellent
Natural ventilated
Naturally lit
Environmental veil and
light shelves
•  Double-skin facade
•  Borehole cooling
Building longevity
The value of a building can be maximised by
considering flexibility and adaptability in design.
Long spans construction is one possible solution.
It allow the space to be arranged to suit open
floor plans, different layouts of cellular offices and
variations in layout throughout the height of the
building.
Building longevity
•  This is an example of modern building life extension
•  The existing roof / wall coverings were completely removed and
replaced with composite panels.
•  The U value and air-tightness of the building were immediately
improved.
•  The portal frame was raised by 3m and an office block added
Building longevity
Can we measure flexibility and
adaptability?
•  Not a lot of work has been done on this.
•  A PhD thesis at the University of Delft has resulted in the
development of a simplified assessment method.
•  This looks at six parameters and their effect on the
Estimated Service Life (ESL) of the building.
•  An ESL<1 means a reduced service life and an ESL>1
means an extended service life.
•  Low score= 0,9*0,7*0,8*0,85*0,9*0,8 = 0,3 (reduce ESL
-70%)
•  High score =1,1*1,4*1,2*1*1,3*1,2= 2,9 (increase ESL
+190%)
•  So, the difference between the impact of best and worst
practice in design for building longevity is almost a factor
of 3.
The DUTCH version of BREEAM
recognises the importance of this
2 credits
Social and ethical considerations
So, where are the problems?
•  The following comments reflect my personal opinion and
not necessarily those of my employer.
•  The construction industry remains cost driven.
•  It is difficult to change practice.
•  The cost of carbon remains low.
•  Each building is a one-off. There is no standardisation.
•  We have failed to match many of the aspirations of the
Egan Report (for example)
Independent: 20th
February 2013
Thanks for listening