Closed Loop Recycling and EN15978 – how does it work?

I’ve heard its complicated why is that?

We need to reward recycling but also have to be careful not to double count the benefits (at the start and end of life for example).  The approach under EN15978 is as follows:

  • to reward “design for deconstruction” as the key driver that determines the net results over the whole life of a building
  • to allocate economically, so if a product is a waste product at the end of the buildings’ life (there is no market for it, so it costs money to remove it from site rather than having some sort of scrap value) then any benefits associated with recycling that product are picked up by the next person who uses it.  So essentially, recycled timber is all rewarded at the start of the building’s life.  Recycled aluminium is all rewarded at the end (in net terms)

Allocation of reused products from other industries are also done economically, one example of this is recycled fly ash or blast furnace slag in concrete.  Because Blast Furnace has some value, it’s not as attractive environmentally as fly ash

The rules for recycling allocation under the EN15978 methodology were initially somewhat mind-boggling for me.  To understand them you will  likely need to take a number of re-visits and you should try to wipe out any preconceptions you may have on recycling.

So how does it work?.

Lets start with what is included in the scope of En15978 first,

boundary

Note that Module D is actually a form of “System Expansion” and one could argue is outside of the life cycle of the building.

Before we look into recycling allocation further we also need to understand a few definitions.

Recycled content is the proportion of recycled material used to create the product, the global industry average recycled content of aluminium today is approximately 35%. This means that in 100kg of aluminium 35kg comes from old recycled aluminium and 65kg comes from new raw material.

Recycling rate is the proportion of useful material that gets sent back into the economy when the product comes to the end of its life. The global industry average recycling rate of aluminium today is approximately 57%. This means that in 100kg of waste aluminium 57kg will be recycled into new aluminium products and 43kg will be sent to landfill.

Closed loop recycling, whereby a product is recycled into the same product (e.g. steel roof panel recycled into steel reinforcement).  The loop is closed because when the steel product comes to the end of its life it can be recycled into a new steel product (theoretically this can happen continually forever).  Closed loop is more straightforward to calculate as the emissions are directly offset by the new product that would have been required to be made from scratch.

Open loop recycling is when the product is used to create something new (e.g. old plastic bottles recycled into carpet).  The loop is open because the plastic now in the carpet required other material inputs to create the carpet and cannot be recycled further (if a process is developed that can continually recycle the plastic carpet then it becomes closed loop). We use economic allocation to understand the impacts that are being offset.

Now lets focus on a closed loop recycling example of a standalone 1000 kg of ‘General Aluminium’ modeled in eTool.  Under EN15978 scope impacts under module D – Benefits and loads outside the system boundary are quantified.  This includes closed loop recycling which is not directly related to the actual physical boundary or life cycle of the building.

The life cycle stages for the aluminium are shown below

alum recy 1

Kg CO2e by LC stage for 1000kg of general aluminium 

Hang on, the impacts are bigger for the 100% recycled content option???

Well, there is an initial saving in the product stage of 18,280 kg CO2e from using 100% recycled content aluminium versus using a 100% raw material. The no recovery option also gets a small advantage for transport of waste (C2) because landfill sites tend to be closer to a building than recycling sites on average. The no recovery option is also (very slightly) penalised for disposal impacts, if the aluminium is recovered it has 0 disposal impacts because it is sent to the recycling plant and these impacts are counted in the A1-A3 stage of the new aluminium product. The interesting result though is in the closed loop recycling.  We have a credit applied to the aluminium that is recovered and put back in the economy. This is effectively offsetting the assumed extraction requirement for the new aluminium to be used in the (aluminium) economy – for example in the next building.  Likewise aluminium that is not recovered causes a higher net demand for new aluminium.  To determine the ‘credit’ or ‘penalty’ at the end of the building’s life, the net increase in new aluminium required due to the use of the aluminium in the building is calculated.  In the 100% recycled content, 0% recovered the material is penalised by the equivalent mass of new aluminium which will need to be extracted to supply the next building.

Hmmmmmm…

Yes it may seem counter-intuitive but try to think of the world aluminium economy as a single life cycle entity.  If everyone used only 100% recycled aluminium that has 0 end-of-life recycling rate (ie it ends up in landfill) then we would soon run out of recycled aluminium available.  We would have to go back to using raw aluminium (maybe even start digging it back out from landfill!).  By encouraging recovery of the aluminium EN15978 is trying to discourage the overall extraction of the raw material.

O.K. That wasn’t too bad

So far so good but it gets trickier! Lets imagine we have fully recycled content and fully recovered aluminium,

Well you get the best of both worlds – reduced product stage and closed loop credits right?

Wrong!  Here is what happens….

alum recy 2

Kg CO2e by LC stage for 1000kg of general aluminium 

The minus CO2e credit at end of life can not be applied in this instance because you are already using 100% recycled aluminium. There is no material extraction in this case to offset and your end-of-life credit is 0. You don’t get penalised for the added extraction for the future building but you don’t get credit for it because that has already been given in the product stage. Under EN15978 there is actually a very similar amount of carbon associated with a 0% recycled/100% recovered aluminium scenario and a 100% recycled/100% recovered aluminium.

Whoa, that’s deep.

Its a tricky one and there is certainly an argument to say this is not encouraging the right behaviour but the emphasis on end-of-life treatment means that the impacts are accounted for and credit is given without double counting.

So what do we take from all of this?

Recycling content and rate is an important consideration in buildings but it is no silver bullet. Every little helps in sustainability though. Focus on the durability and deconstructability of the product over the recycled content which under EN15978 has a relatively small impact on the environmental performance.

*Note figures show are taken from eToolLCD September 2016

References: Recycling Rates of Metals, T E Graedel, 2011

Benchmarking Philosophy

eTool recently changed from offering numerous fairly localised benchmark options to a single international average benchmark for each building type.  The decision making process was interesting so I thought I’d quickly document it.

The purpose of the eToolLCD benchmark is:

  • To establish a common measuring stick against which all projects are assessed so that any project can be comparable to another (for the same building type);
  • To create a starting point, or “average, business as usual case” from which to measure improvements.

From the outset we’ve always understood that a benchmark needs to be function specific.  That is, there needs to be a residential benchmark for measuring residential buildings against etc.  The first point essentially addresses this.

The second point introduces some complexity.  What is, or should be, “average, business as usual”?  More specifically, are people interested in understanding how their building performs when compared compared locally, regionally, nationally, or internationally?

When we started trying to answer this question, some scenarios were very helpful.  If a designer wants to compare locally, the benchmark needs to reflect the things that are most important to the overall LCA results.  The two most critical things are probably electricity grid and climate zone.  Localising just these two inputs gets pretty tricky and the number of possible benchmark permutations starts to add up pretty quickly.  In Australia there are four main independent electricity grids (NEM, SWIS, NWIS and Darwin).  In the Building Code of Australia there’s 10 climate zones.  Accounting for which climate zones occur within each grid, there’s about 20 different benchmarks required.  To add to the complexity though, the NEM is split into different states (New South Wales, Victoria, Australian Capital Territory, Queensland, Tasmania and South Australia).  Generally, because the National Greenhouse and Energy Reporting guidance splits the NEM into different states, the NEM is usually considered as six different grids. So there’s upwards of 50 different benchmarks we’d need to create and maintain for Australia alone just to localise electricity grids and climate zone.

One disadvantage of this method is it’s still not all-accommodating.  It doesn’t account for remote grids of which there are many in Australia.  An example is Kunnanurra which is 100% hydro power.  So even in this scenario where we had 50 or so benchmarks for Australia, there’s still big potential for a designer patting themselves on the back for a great comparison to the benchmark when really it’s just a local condition, and vice versa.  The same can be said about an off grid scenario (effectively just a micro grid of it’s own).

The other disadvantage is maintenance of all these benchmarks.  Expanding the above scenario internationally there could easily be 1000’s of possible benchmarks.  There’s so many that it would be hard for eTool to initially create them, and even harder to subsequently maintain them.  Clearly the localised benchmark option had some big challenges.

At the other end of the benchmarking philosophy we considered just having generic benchmarks, or even one global benchmark.  This is perhaps a more user-centric, or building occupant sensitive system.  That is, the building occupants are probably more interested in this measure as it’s more about how they live compared to the global community.  So a building may be “average” compared to the local context, but actually be very low impact compared to the broader average (due to favourable local conditions).  Conceivably, the local conditions contributing to the ease with which a building can perform may be part of people’s motivation for living in a particular area.

The disadvantage of the generic benchmarking approach is that it isn’t as useful for a designer to compare their building’s performance against this as the local conditions (which may create a significant advantage of disadvantage) aren’t considered.  This was a big consideration for us, eToolLCD is a design tool, it has to be relevant to designers.  Interestingly though, the way eToolLCD is generally used is the base design is modelled, and then improvements are identified against this base design.  The benchmark is usually only used towards the end of the process as a communication and marketing tool.

Also, there’s no reason why the designer can’t model their own local benchmark, for example, a code compliant version of their own design.

This topic spurred some serious debate at eTool.  In the end, the deciding factors were:

  • A local approach couldn’t really be adopted without localising at least the grid and climate zone for each benchmark option.  That is, it would have been too difficult to go half way with localisation (for example, only localising climate zone and not grid), as this really just revoked the whole advantage of localising the benchmarks.
  • Taking the very localised approach was going to put a huge benchmark creation and maintenance burden on eTool which wasn’t necessarily productive
  • The choice of a generic benchmark didn’t detract from the function of eToolLCD as a design tool.
  • Greenhouse Gas pollution is a global problem not a local problem, we feel people probably need to measure and improve their performance against a global benchmark rather than a local one.

So the single global benchmark was the direction we choose.  Once this decision was made, we needed to determine how to statistically represent global averages.  We decided to choose an aspirational mix of countries to make up the global benchmark, that is, select the standard of living that we felt most people in the world aspire to and determine the average environmental impacts of buildings in these demographic locations.   This does mean the global benchmarks are generally higher than the actual global average building stock for a given function.  That doesn’t stop us from estimating what the sustainable level of GHG savings is against this aspirational benchmark (90%+).  It also enables us to strive for this level of savings without adversely effecting our standard of living aspirations (globally).  The global benchmark created using this approach is the residential benchmark.  More information about how this was conducted can be found here.

For those people or organisations that would like a customised benchmark, eTool can provide this service.  Please get in touch.

Impact Category Definitions

What are all these new impact categories eTool can now measure?  Below are some definitions:

Climate Change impacts result in a warming effect of the earth’s surface due to the release of greenhouse gases into the atmosphere, measured in mass of carbon dioxide equivalents.

Stratospheric Ozone Depletion is caused by the release of gaseous chemicals that react with and destroy stratospheric ozone. Although the Montreal treaty has significantly reduced the use of the most damaging substances and there is evidence that the abundance of ozone depleting gases is reducing in the atmosphere, some releases of ozone depleting chemicals still occur.

Acidification Potential provides a measure of the decrease in the pH-value of rainwater and fog, which has the effect of ecosystem damage due to, for example, nutrients being washed out of soils and increased solubility of metals into soils. Acidification potential is generally a regional impact and is measured in mass of sulphur dioxide equivalents. The mechanism dominating the acidification impacts is the combustion of fossil fuels, release of sulphur dioxide and nitrogen oxide which dissolves with condensed water in the atmosphere and falls as rain. The term acid rain describes severe incidents of this mechanism.

In general terms, Eutrophication Potential provides a measure of nutrient enrichment in aquatic or terrestrial environments, which leads to ecosystem damage to those locations from over enrichment and is measured in mass of phosphate equivalents.

Tropospheric Ozone Formation Potential is the creation of lower atmospheric ozone (commonly known as smog) due to the mechanism of VOCs reacting with sunlight. In particular, the release of carbon monoxide from steel production is predominant; however other releases such as nitrogen oxide, sulphur dioxide and methane also contribute significantly to POCP.

Mineral & Fossil Fuel Depletion (Abiotic Depletion) provides an indication of the potential depletion (or scarcity) of non-energetic natural resources (or elements) in the earth’s crust, such as iron ores, aluminium or precious metals, and it accounts for the ultimate geological reserves (not the economically feasible reserves) and the anticipated depletion rates. It is measured in mass of antimony equivalents.

Human Toxicity, in general terms, refers to the impact on humans, as a result of emissions of toxic substances to air, water and soil, and is expressed in terms of damage to human health by the index mDALY (1/1000th of a disability adjusted life year)

Land Use is measured in years of use of arable land (m2.year). This describes the area and time land is occupied by production systems both natural and industrial for the production of the building materials but not the occupation of the building itself. While not strictly an impact category it is linked to general land use pressure and is therefore a proxy for biodiversity and other land competition impacts.

Resource Depletion (Water) provides an indication of the total net input of water used throughout the life cycle of the building.

Ionising Radiation covers the impacts arising from the release of radioactive substances as well as direct exposure to radiation. The impact is expressed in terms of damage to human health by the index uDALY (1/1,000,000th) of a disability adjusted life year.

Ecotoxicity refers to effects of chemical outputs on nonhuman living organisms. Expressed in comparative toxic units (CTUe) it provides an estimate of the potentially affected fraction of species integrated over time and volume per unit mass of a chemical emitted.

Particulate Matter is defined as a mixture of solid and liquid particles of organic and inorganic substances resulting from human activities and suspended in the atmosphere. Several studies show that PM causes serious adverse health effects, including reduced life expectancy, heart disease, lung cancer, asthma, low birth weight, and premature birth. Precursors involved in PM formation include sulfur dioxide (SO2), nitrogen oxides (NOx), ammonia (NH3), and volatile and semivolatile organic compounds. Measured as either PM2.5 (particulate matter smaller than 2.5 micrometers) or PM10 (particulate matter between 2.5 to 10 micrometers). Finer particles can travel deeper into the lungs and are usually made up of materials that are more toxic therefore PM2.5 can have worse health effects than the coarser PM10.

Other LCA Tools

LCA is awesome! And if using eToolLCD software doesn’t leave you with that feeling then don’t point the finger at LCA, find some software that suits your needs better. Here’s a list of other tools to explore.

TOOLPROVIDERRegion
BEATDanish Building Research InstituteEurope (Denmark)
Bionova360 OptmiFinland
e-LICCOe-LICCOEurope (France)
ElodieCSTBFrance
eTooleToolGlobal (From Australia)
GaBiPE InternationalGlobal (From Europe)
GreenflyRMIT University
Sustainability Fund (Victoria)
Design Institute of Australia
Global (From Australia)
IMPACTIESGlobal (From UK)
Impact EstimatorThe Athena Sustainable Materials InstituteNorth America
KlimagassregnskapStatsbygg (Norway)Europe (Norway)
LCA CalculatorIDCGlobal (From UK)
SimaProPRE SustainabilityGlobal (From Europe)
Sustainable MindsSustainable MindsGlobal (From US)
TallyKieranTimberlakeNorth America