Technical

Technical

Who recognises LCA?

Life Cycle Assessment is recognised internationally in standards, rating tools and even legislation.

Standards

Life Cycle Assessment is recognised by the International Organisation for Standardisation (ISO) through standards 14040 and 14044 which deal directly with LCA.  LCA is also heavily referenced or relied upon in many other ISO standards covering environmental assessment of products, services, buildings and civil structures.  Essentially, when it comes to assessing environmental performance, ISO standards prefer the use of LCA.

The European Centre for Standardisation (CEN) also heavily rely on LCA for assessing the environmental performance of buildings and building products (standards EN15978 and EN15804 respectively).  These standards are quickly becoming recognised internationally.

Of course this all makes sense, when you do stand back and think carefully about how to guarantee that a design decision you’re making truly leads to a net improvement in performance, you need to understand the life cycle impacts associated with that decision.  It’s really the only way to be sure a design choice isn’t leading to poor trade off’s.  The technical committees that were tasked with standardising “Assessment of the Environmental Performance of Buildings” had many existing systems and approaches to choose from around the world.  LCA emerged as the best option available.

Building Rating Systems

The uptake of whole building life cycle assessment has been accelerating in recent times as it becomes  more practical to implement. Even existing rating systems are quickly embracing and integrating it into their systems.  These systems include:

  • US Green Building Council: LEED
  • BRE (UK): BREEAM
  • Living Future Institute (US): Living Building Challenge
  • BioRegional (UK): One Planet Living
  • Green Building Initiative: Green Globes
  • German Sustainable Building Council (DGNB): DGNB System
  • Green Building Council of Australia: Green Star

LCA is utilised differently by these different systems.  In the case of the DGNB it’s a very significant part of the total scoring system, where as other systems are only just starting to introduce LCA.  Whole of building LCA has only become practical reasonably recently, and it’s uptake is accelerating, both in the number of systems that are incorporating it, and also the weighting.

Legislation

Governments are beginning to recognise that the way we are running our economy is unsustainable, particularly with the issue of climate change. The world needs to reduce GHG emissions per capita by approximately 80%, and developed countries by 95% to achieve sustainable levels of greenhouse gas emissions. In the construction sector, although no regulations have yet specified LCA of whole buildings, this avenue is being seriously considered. Washington State Senate commissioned a study to explore the potential of integrating life cycle assessment methods, data and/or standards into the state building code. Findings supported implementation but not immediately as the industry needs time to develop LCA skills and data. External to building regulations a number of product labelling programs have also unfolded to introduce transparency regarding embodied carbon of products.  These programs rely on LCA to determine a product’s carbon footprint.  The following programs are all using LCA to quantify and compare environmental impacts of consumer products.

  • France introduced a national pilot program of LCA based environmental labelling under the Grenelle 2 Act.
  • South Korea initiated a carbon labelling program for consumer goods and services. The system is voluntary but instigated by “The Fundamental Law for Low Carbon Green Growth, 2010”. 600 goods and services currently certified and labelled.
  • Japan’s Ministry of Economy, Trade and Industry started a pilot labelling program in 2008. Over 300 retailers and manufacturers are involved across 53 product categories.
  • Thailand have introduced a pilot CO2 labelling program through the GHG Management Organisation. Launched in 2010, 458 products from 100 companies are carrying the label.

Posted in: Technical

How much CO2 is the built environment responsible for?

A number of sources are now confirming the huge impact of buildings on the environment.
When both embodied and operational emissions are accounted for, most estimates seem to fall between 30 and 40%, although some studies indicate it is even higher.

“Worldwide, 30-40% of all primary energy is used in buildings.” United Nations Environmental Program, 2007

“The commercial and residential building sector accounts for 39% of carbon dioxide (CO2) emissions in the United States.” United States Green Building Council, 2009

“According to the U.S. Energy Information Administration (EIA), nearly half (46.7%) of all CO2 emissions in 2009 came from the Building Sector.” Architecture 2030, 2011

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What is Life Cycle Assessment or “LCA”?

LCA is an accounting method that assesses each and every impact associated with all stages of a product or process over its life span. The approach is sometimes referred to as a “Cradle to Cradle” assessment if it accounts for full recycling at the end of the products design life or just “Cradle to Grave” if it takes the product through to disposal only.

For more details please download our paper on the science of LCA in the built form here.

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How does LCA relate to the built environment in regards to energy and carbon?

LCA of the built form involves quantifying the total “Embodied Energy” and the “Operational Energy” over the entire design life of the building (click here to see LCA graphic). Energy can then be converted in CO2e using applicable coefficients relevant to the primary energy source and efficiency.

For more details please download our paper on the science of LCA in the built form here.

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What does “Embodied Energy” mean in reference to the built environment?

Embodied Energy refers to the energy and/or carbon required to construct and maintain a building over its entire design life (click here to see LCA graphic).
Embodied Energy can be broken down into the following components:

  • Materials – Energy used to extract the raw materials and process them into useable building products available at the gate of the factory (“Cradle to Gate”).
  • Transport – Energy used to transport the building materials from the factory gate to the building site.
  • Assembly – Energy used to construct and create the building.
  • Recurring – Energy used to maintain and replace certain building elements over the entire life span of the building.
  • Demolition and Recycling – Energy used to demolish and recycle the building and feed the resultant materials back into the building materials “food chain”.

For more details please download our paper on the science of LCA in the built form here.

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What does “Operational Energy” mean in reference to the built environment?

The “Operational Energy” is the amount of energy required to run the building over its design life and includes appliances such as Air-Conditioners, Hot Water systems, Refridgeration and Lighting.

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How much “Embodied Energy” is there in an “average” building?

As there are limited numbers of LCA’s of buildings completed in Australia, the sample group is too small to quote what an “average” might be. However after conducting numerous LCA’s on “benchmark” or “standard” Australian residential designs we have found that “Embodied Energy” is responsible for approximately 35% of the a buildings carbon footprint.

As we rapidly populate our database of designs globally we will be better positioned to provide more accurate statistics on “average” values. To put this in perspective, in Australia air conditioning is responsible for approximately 23% of the buildings total carbon footrpint over its design life. With “Embodied Energy” at 35% we feel that it is imperative that the use of eTool and LCA compliment the legislated design requirements for the thermal performance of buildings in Australia.

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How can LCA compare different types of buildings?

eTool have “Benchmark” buildings for different primary building uses.  Benchmarks are a weighted average calculation of embodied and operational carbon for the new buildings of that primary purpose.  For example, our residential benchmark reflects the new residential dwelling mix in Australia.  That is, we’ve looked at the national Australian Bureau of Statistics data for new dwellings, determined the mix of low, medium and high density buildings, established a weighted average size of dwelling and then determined the embodied carbon of that size of dwelling.  We have then profiled average energy consumption for new homes, adjusted for the climate region (which affects the thermal performance component).  We have ensured that all energy consumption stats are calculated on building code compliant structural, design and energy efficiency measures.  This gives us a measuring stick against which all new residential premises can be compared, our “Benchmark”.  Ideally we want to reduce the impact in comparison to this “average” for new dwellings.

The obvious question regarding the above approach is that we’re not comparing like for like. For example, how can we compare a detached house to a multistory residential apartment block?.  By using a functional unit of “impacts / occupant / year” we are normalising results to allow comparisons despite wildly varying building sizes, styles, densities etc.  Without the functional unit the eTool benchmark buildings would be useless to compare against.  The power of the functional unit is that it enables all buildings to be compared, thereby the advantages (or otherwise) of totally different housing approaches can be assessed against the “business as usual” approach.

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LCA v LCCA

Life Cycle Assessment (LCA) is covered by ISO 14040 and 14044; it is a method of assessing the environmental impacts of a product or service. LCCA (Life Cycle Cost Assessment) is covered by ISO 15686 – 5 and gives guidelines for performing life cycle cost analysis of buildings and constructed assets.
eToolLCD has been developed to meet LCA standards, and although is a very useful tool for life cycle cost assessments, the standard reports generated by eToolLCD don’t necessarily meet ISO 15686 – 5 (LCCA).  Neither of these standards are particularly well known and we have been providing both services to clients in the past to their satisfaction.

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Do you account for building design life?

Absolutely, design life is a critical component of good LCA performance.  The studies suggest that for buildings, the actual service life is dictated by redevelopment pressure, not durability.  If it’s a detached residential building in a high density area it is likely to be subject to very high redevelopment pressure in the not to distant future.  If however a building is very high density, or in a very low density area it’s not going to be under nearly the same pressure for redevelopment.  Further to this, by applying good future proofing design principles and superior design quality, design life may also be extended.  In determining the environmental impacts of a building design life and functionality can be the biggest determinants.

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How is the benchmark building created? Who manages this, and how do you stop people from manipulating the benchmark buildings?

eTool model the benchmark buildings based on a weighted average building density, size and functionality of new stock for the type of building undergoing the LCA.  In essence, the benchmark is a nominal statistical average of buildings that provide the same function.  For example, for residential buildings, we look at the weighted mix of existing housing stock, the size and occupancy.  From there we make adjustments to ensure modern day code compliance.  The benchmarks have to be specific for each region to account for building codes and climate variables  For example, there are major differences between a code compliant building in the US verse Australia.  Our current published benchmarks are all Australian buildings at present but we’re extending the library internationally as we speak.  eTool create and manage all the benchmarks, it’s not a user defined thing and therefore all LCAs conducted in eTool are comparable for a particular building type in a particular region.

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Which materials should we shift away from and what should we stick with to get a better LCA result?

It’s really dependant on the building.  Sometimes it actually makes sense to use high embodied impact materials because they provide durability, but this is only justified in buildings that are likely to still be standing in 100 years or more.  It also depends on the interaction between thermal performance and the materials.  There’s often a few iterations involved to perfect the mix.  General rules of thumb though would be, for buildings with a short expected life span, light frame construction is preferable, for buildings with a long life span, the focus often has to be on reducing recurring impacts from maintenance activities (paint, carpets, plasterboard etc).  Natural finishes are a good way of combatting this.

Posted in: Technical

How Does eTool Define Building Areas?

The following table shoes how eTool will be soon defining areas within the software (if not already!):

Australian Construction Handbook Definitions (Rawlinsons)Simplified eTool NotesUK Equivalent
TermAbbreviationDescription
Gross Floor Area GLAThe sum of the Fully Enclosed Covered Area and Unenclosed Covered Area as defined.No ChangeGross External Area
Fully Enclosed Covered AreaFECAThe sum of all such areas at all building floor levels, including basements (except unexcavated portions), floored roof spaces and attics, garages, penthouses, enclosed porches and attached enclosed covered ways alongside buildings, computed by measuring from the normal inside face of exterior walls but ignoring any projections such as plinths, columns, piers, and the like which project from the normal inside face of exterior walls but ignoring any projections such as plinths, columns, piers, and the like which project from the normal inside face of exterior walls.  It shall not include open courts, light wells, connecting or isolated covered ways and net open areas of upper portions of rooms, lobbies, halls, interstitial spaces and the like, which extend through the storey being computed.As for Rawlinsons but projectiosn are generally included in the measurement and measurement may be from the outside, centre or inside of external walls depending on the models and plans used to develop the inventoryGross Internal Area
Unenclosed Covered AreaUCAThe sum of all such area at all building floor levels, including roofed balconies, open verandahs, porches, porticos, attached open covered ways alongside buildings, undercrofts and useable space under buildings, unenclosed access galleries (including ground floor) and any other trafficable covered areas of the building which are not totally enclosed by full height walls, computed my measuring the area between the enclosing walls or balustrade (i.e. from the inside face of the UCA. excluding the wall or balustrade thickness).  When measurements shall be taken to the edge of the paving or to the edge of the cover, whichever is the lesser.  UCA shall not include eves, overhangs, sun shading, awnings and the like where these do not relate to clearly defined trafficable covered areas, nor shall if include connecting or isolated covered ways.As for Rawlinsons but area of balustrades is generally included and measurement may be from the outside, centre or inside of external walls depending on the models and plans used to develop the inventory
Building AreaBAThe total enclosed and unenclosed area of the building at all building floor levels measured between the normal outside face of any enclosing walls, balustrades and supports.No Change
Usable Floor AreaUFAThe sum of the floor areas measured at floor level from the general inside face of walls and all interior spaces related to the primary function of the building.  This will normally be computed by calculating the Fully Enclosed Covered Floor Area (FECA) and deducting all the following areas supplementary to the primary building function:
– Common Use Areas: All floored areas in the building for the circulation and standard facilities provided for the common use of occupiers, tenants and / or the public such as lobbies and foyers to entrances, lifts, landings, and fire escapes, verandahs and balconies, corridors and passages, toilet and rest room areas, cloak and locker areas, cleaners rooms including stores and cupboards, tea making and similar amenities.
– Service Areas: All areas set aside for the building plant supplying services and facilities common to the building for the use of occupants, tenants, and / or the public such as mechanical plant and equipment rooms, electrical equipment and switch rooms, tank rooms, lift motor rooms, meter cupboards, telecommunication switch rooms, refuse collection areas, loading bays and all car parks including access ways thereto.
– Non Habitable Areas: All non-habitable building space such as that occupied by internal columns and other structural supports, internal walls and permanent partitions, lift shafts, service ducts and the like.
As for Rawlinsons but will generally include non habital areas.Net Internal Area
Treated AreaTAThe sum of all areas at all building levels to which a particular engineering services is provided.  The area is computed by measuring from the normal inside f ace of exterior walls, but ignoring any projections such as plinths, columns, piers, and the like which project from the normal inside face of exterior walls, to the center line of internal walls, as applicable, which enclose the area treated.   NOTE:  Treated area may need to be calculated separately for each engineering service.  The treated area to such services as space heating, ventilation, evaporative cooling and air-conditioning should include all areas to which the treated air is supplied.  The treated areas for fire protection comprises the sum of protected floor space, the area of protected ceiling spaces and the area of protected under floor spaces.As for Rawlinsons, generally only appried to “Conditioned Area”
Net Lettable Area, Office BuildingsNLAThe sum of all lettable areas within a commercial type office building, measured from the internal finished surfaces of permanent walls and from the internal finished surfaces of dominant portions of the permanent outer building walls, and including the area occupied by structural columns, and engaged perimeter columns, all in accordance with the Method for the Measurement for Lettable Area issued by the Property Council of Australia.  Deductions from NLA:
– All stairs, toilets, cleaners cupboards, lift shafts, escalators, and tea rooms where provided as standard facilities in the building.
– Lobbies between lifts facing other lifts serving the same floor
– Areas set aside as public space or thoroughfares and not used exclusively by occupiers of the building (NOTE: Excludes any additional common areas resulting from subdivision of a whole floor to accommodate more than one tenant)
– Areas set aside as plant and lift motor rooms of for the provision of facilities or services to the building and not for the exclusive use of an occupier or occupiers of the building
– Areas set aside for use by service vehicles and for delivery of goods and access ways thereto
– Areas set aside for car parking and access thereto
– Areas where clear height is less than 1.5m
As for Rawlinsons but will generally include non habital areas.

 

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