ArchiBlox Creates Australia’s First Carbon Positive Pre-Fab Home

Going beyond carbon zero.

Archiblox’s latest project is a carbon positive modular home that boasts a difficult to attain eTool Platinum rating. Achieving a platinum rating means the design achieved a 90 per cent overall improvement in CO2e emissions compared to the Australian benchmark along with a minimum of 60 per cent improvement in each category (embodied carbon and operational carbon).

What does it mean to be carbon positive?

A net carbon positive outcome means the building offsets more carbon than it uses in construction and operation throughout the life of the building.

Check out the following press about ArchiBlox’s carbon positive home and if you are in Melbourne, you can check the house out at the Sustainable Festival running until 1 March.

Australia’s first carbon positive pre-fab home– SBS News

Can you compete with a carbon positive prefab home?” – Architecture & Design

“World’s first carbon positive prefab house” Green Magazine

“World’s first carbon positive prefab house?” – ArchitectureAu

“The World’s First Carbon-Positive prefab house” – Dwell Magazine

“Prefabricated house in Melbourne’s City Square can produce more energy than it uses” – Dezeen Magazine

Sun Room in the Modular Design. Click to view the full case study >

Sun Room in the Modular Design. Click to view the full case study >

 

Zero-Carbon Buildings? It’s the Wrong Target

Well this is a bit of an odd post as it’s result of me getting carried away in a LinkedIn conversation and blowing the word limit considerably. I’ve ended up posting only the key points on the “linked in” conversation and the detailed response here.

To understand the background please have a look at this conversation (I think you’ll have to sign up to be part of the group) and this blog article. From there you will see where the rest of this following rant comes from.


 

I think this is pretty massive topic requiring a lot of discussion to get some good outcomes. I’ve ended up with a 50page response as a result.

It also has taken a few tangents which I’ll try to bring back into line with the original topic by breaking it down into four points:

  1. If you are taking aim at a particular legislation be very clear in your article that is your purpose.
  2. Don’t be prescriptive in your design approach and push only one strategy (such as passive house) or you’ll get perverse outcomes.
  3. Don’t write off onsite renewable energy it’s on the increase for some good reasons and is only set to grow even further – embrace it where it works.
  4. I’ve also gone to address several of your points in detail to provide some more structure to your original article

Those points in detail for those interested enough to read the 50 pages now….

 1. If you are taking aim at a particular legislation be very clear in your article that is your purpose.

I was lead to believe it was all about reducing carbon and what targets to set to get there.

I’ll repeat – I’m not across the UK definition of “zero carbon house” and again if your aim was to identify flaws in it then please reword your opening paragraph as well as the bulk to ensure it’s more “explicitly” stated throughout the article. Otherwise it will continue to read as anti onsite renewables, pro passivehouse and not UK specific. This is really dangerous and we will continue to have people around the world blindly following a design strategy that can often result in bad outcomes for the planet.

You have also introduced “comfort targets” into the conversation which I agree is an important element to good design. However if we are targeting CO2e reductions “comfort targets” need to be defined as what is sustainable for 7b people on the planet and not just a lucky few who can live in large “eco” houses. I think this is another topic for another conversation….

If you’re aim in the article was to create some healthy debate then it was spot on 😉

2. Don’t be prescriptive in your design approach and push only one strategy (such as passive house) or you’ll get perverse outcomes.

If reducing CO2e is the goal then CO2e is the only priority when it comes to design strategy. More importantly CO2e should be the basis of your target not “energy efficiency”.

I am totally agnostic in regards to which strategies (be it passivehaus or solar pv) should be prioritised in a project until we have kicked of with Life Cycle Design. Then and only then can you start to see which strategies will provide a genuine reduction in CO2e over the buildings life cycle.

In my home city of Perth we have a Goldilocks climate and very carbon intensive grid which is no where near being destabilised by PV. Unfortunately we still have the vast majority of “eco” designers using all of their clients money to design something that doesn’t need an air-conditioner while having no budget left for solar hot water or solar pv. They’ll reduce their carbon footprint by 10% while the guy down the road in a standard design with solar hot water and solar pv will have a 90% reduction in carbon, lower operating costs and all with less than half the capital cost.

Worse still they’ll chuck large volumes of concrete into the design for thermal mass in the push to achieve the magic “energy efficient” design resulting in an overall increase in life cycle carbon (even with a carbon intensive grid).

If you took the same example up to Kununurra, with a hydro dominated grid, then the solar pv would be a waste of embodied carbon as would the majority of the “radical energy efficiency” strategies. In that circumstance it would all be about the embodied carbon in the materials, transport, construction and maintenance.

Shift it again to various locations in the UK and I bet you’ll find a whole set of new variables and changes in priorities for strategies. Again starting with blanket statements about what should be prioritised without checking each project variables first will result in perverse outcomes.

I know you guys have a much colder climate than we do but I’m still pretty confident that with a proper LCD approach onsite renewables (PV, solar hot water, pellet heater etc) will still come into the mix for a low carbon design.

LCD ensures you apply a rigorous and unbiased approach to each project and provide something that planet and the occupant can be happy with. I would suggest that become familiar with standards such as EN15978 as it will allow you to integrate passivehouse within a much more holistic design philosophy. EN15978 is scientific approach to assessing the environmental performance of a building and is not biased by any existing rating system, design concepts or technology. It’s fast becoming the new benchmark for good design

 

3. Don’t write off onsite renewable energy it’s on the increase for some good reasons and is only set to grow even further – embrace it where it works.

“It is less costly and more effective to consume radically less energy and emit less CO2 by design, rather than to meet higher energy demand with building mounted ‘Zero-Carbon’ renewable generation.”

Sorry, but this statement is just not true. In some cases the opposite is more accurate. Again horses for courses! I think I addressed this point somewhat above.

Solar PV has dropped in price dramatically and continues to do so. Distributed storage is now doing the same. So if you continue to ignore it or try to push it to the side you will be left behind. Yes it does have it’s challenges as does any developing technology but they are disappearing fast.

I did read that article from Japan and it’s interesting we had a very similar situation in Australia a few years back. In small isolated network there was a really fast uptake in PV and the local utility got scared of stability issues and put a halt on further installations. As a result the industry responded by integrating cost effective distributed storage and away it went again. I’d almost guarantee we’ll see similar responses around the globe not to mention increase in electric vehicles.

Installing PV on roof in Perth can be as cheap as a solar farm ($1-2/Wp). There is already frames (the roof), electrical infrastructure (existing switchboard and meters) and no land costs. More importantly they are off the shelf items without need for expensive engineering, approvals and regulations. As far as this scary maintenance cost the systems I’m familiar with in Perth over 8years old have never skipped a beat. It just comes down to a life cycle cost analysis and trust me it looks pretty good with people taking it up purely on a cost basis with no rebates.

4. Specific points in your original article

“4. ‘Zero-Carbon Buildings’ may increase national CO2 emissions”

Why can’t these buildings also run gas and have the best of both? This is a pretty massive long bow to draw and very misleading to say that it will increase demand on the network.

“In the dark freezing depths of winter, with a gale howling outside, everyone has their heating turned up high and all the lights switched on … and since the sun isn’t shining the photovoltaic systems on the ‘Zero-Carbon Buildings’ aren’t generating electricity. And since the wind is gale force and highly changeable the wind turbines have switched to safety-mode and aren’t generating electricity!”

Wow, this is sounding like some of the anti renewable energy climate change skeptics. Again can’t the house have both renewables and gas? Furthermore distributed storage is on the way and on the way fast. If you don’t think so then have a think about the people who said mobile phones would never get past one per 200 people.

Houses with onsite renewable energy somehow increase the demand on the network even in hot climates?? Well I can tell you from personal experience in Perth we saw the government build another $300m power station to deal with this peak only to find that solar pv cut the peak dramatically and they never turned it on. Again you need to ensure you’re treating each project on it’s merits and not casting blanket statements or you’ll get tripped up.

 8.‘Zero-Carbon Buildings’ is an abstract and unreliable idea

Sorry this is totally incorrect and also damaging to the progress we are making in getting people to think about CO2e. EN15978 lays it out pretty simply. Run a Life Cycle Assessment and you’ll have a much more reliable picture of reducing CO2e in a building.

Energy is not CO2e much like food cost is not measured in volume of food. Saying the only way to reduce CO2e in a house is to focus on radical energy efficiency is like saying we are going to cut our weekly food bill by eating less volume. So off you go to the shops and buy cheese wine and caviar and cut out the bread, rice and fruit (too much volume), furthermore you stop eating the produce from your own veggie garden. Somehow your food cost went up?

Many forms of energy have really low carbon intensities, some you can grow at home with very small carbon intensities and sometimes investing large amounts in energy efficiency can increase your carbon emissions.

Please explain how tackling CO2e by looking at energy and not CO2e be can less abstract than just targeting the CO2e in first place?

 

To wrap it up in conclusion this whole article first up appeared to be about reducing CO2e associated with houses. If this is the goal (which it should be) then setting a “zero carbon” target is exactly what we need to do. Simple….

Regards,

Alex

All Essential List of 12 For a Carbon Zero Lifestyle

[Find original publication here]

A Carbon Zero Lifestyle

Alex hi res- Jan 2013I often get asked by homeowners and self-builders what really makes the biggest difference to the carbon footprint of a home design. Here are my 12 essential bases to cover if you want to go zero carbon but have a strict budget.

1. Life cycle design philosophy

What’s this “Life Cycle Assessment” or LCA thing about? Life Cycle Assessment can be used to calculate all the impacts of your design choices in terms of carbon, cost, greenhouse gas emissions, water, toxicity and more. Quantify and compare to improve your design and don’t forget to question everything.

2. Make it financially attractive
There isn’t much point making a house carbon neutral if it costs the earth, so invest in areas that are going to give you the best return financially and maximise your positive impact on the planet. Before you commit to any design decision, ensure you understand the capital outlay, cost savings and importantly the resulting carbon footprint.

3. Design for the future
Is your design a fashion fad or a timeless classic? Unfortunately, most houses in Australia are lucky to hit their 40th birthday before they are knocked down, so it’s important to consider the following:
• Planning and density – don’t build a detached house in a high density suburb or it will just get knocked over and replaced with townhouses.
• Future proof it – think ahead to what people might want after you’ve finished living there.
• Quality build – a house that is energy efficient, comfortable, functional, well built and well finished is going to last a lot longer than a dated, impractical, energy guzzling beast.
• Durability – if you are aiming for the house to live to a ripe old age, use durable materials.

4. Make it functional
The more people a house can house, the less impact per person that house will have on the environment – it’s that simple. Plus, the more functional a building is, the more likely it will live to retirement instead of retrenchment.

5. Quality not quantity
In Australia, our dwellings have grown 40% in size in the past 20 years, with 10% less people living in them.That means a house built in 1990 is 40% smaller than what we are building now and pretty much has 40% more impact on energy bills and the environment. So, build a smarter, smaller house with the architecture that works well and feels comfortable.

6. Low embodied energy materials
Try to use materials that aren’t responsible for too much – or zero – environmental damage in their manufacture. Think about where and how that product started its life and how it got here. As we transition towards renewable energy, the carbon impact of operating a house (like air-conditioning) will be reduced.

7. Reduce, reuse, recycle materials
Yep, this old chestnut again. Reduce – redundant materials and use raw or natural finishes that don’t require ongoing maintenance. Reuse – whatever you can from the last building or other local “retrenched” (knocked down) buildings. Recycle – materials from the last building and incorporate recycled and recyclable materials into the design.

8. Local, local, local but sometimes not
It makes sense to use locally produced materials and trades as less transport usually means less carbon. However, sometimes you’ll be looking at a compromise between a material that is local but with a high embodied energy versus an imported product that might be recycled. And when you’re considering transportation, investigate efficiency: could shipping from China be less than trucking from Perth to Melbourne?

9. Make it “climate sensible”
After embodied energy,“heating and cooling” are big factors when it comes to your home’s carbon footprint.We are getting better at this impact and Australia now has “six star” regulations that ensure that any new home build will have a fairly good level of thermal performance. It’s good to aim higher than this, but make sure you’re not compromising other aspects of your carbon footprint or return on investment. Consider how much energy and cost went into making that concrete slab you’ve used to get thermal mass and star rating up.

10. Hot water (don’t land in it)
When it comes to running your home, hot water and appliances will impact your energy bills the most, so consider them right from the start. Hot water systems such as solar hot water shouldn’t be viewed as a “bolt on” or “wait and see if we’ve got the budget” item. Make an informed decision on capital outlay versus ongoing savings.

11. Renewable energy
We all love renewables.They can provide a great return on investment and at the same time lower your overall carbon footprint. That said, try not to fall into the trap of thinking “no dramas, I’ll just add a few more solar panels to deal with that”.The embodied energy that goes into making things can never be recovered so make sure you always go back to where did it come from?

12. Low carbon doesn’t always mean sustainable
Reducing your home’s carbon footprint is only one metric of sustainability and it’s just as important to consider the way we behave in our own homes.Technology like real time energy monitoring has shown to reduce energy consumption by around 10% by affecting occupant behaviour. That’s a bigger impact than increasing star rating from six to seven stars.

Life Cycle Assessment (LCA) vs Life Cycle Design (LCD)

While people are still coming to terms with what Life Cycle Assessment (LCA) is, and why it is such a powerful tool to improve the way we build, here at eTool we’ve already moved to referring to Life Cycle Design or LCD.

Yes, it kind of does sound like some new audio visual technology or maybe even a hallucinogenic, but we think it’s super important put the word “Design” into the picture early on.

Heres why: eTool was always founded on the core concept of improving the way we design and build and definitely did not want to create another rating system. Our software eToolLCD is first and foremost a design tool, and it’s in the early design concept phase where you’ll get the best value for the planet and the economy.

Unfortunately, the building industry too often see ESD (again, not another hallucinogenic) or green rating systems as something you tack onto the end of a design process, and LCA definitely ran the same risk. While it’s just a word, “Assessment” at the end of “Life Cycle” just helped project stakeholders think that it should be pushed to the end of the design rather than right up front.

It’s almost guaranteed that outcome will be improved by having basic discussions around functionality before the client put pen to paper developing a design brief. Please ensure you get in contact with us as early as possible to discuss your next project or concept.

RatingToolChart

eToolLCD Advanced Training

LCA Training with eToolLCD 

eTool hosts an Assesor Lite training over the course of two half days where participants will gain a hands-on understanding of life cycle assessment and eToolLCD. The training is held at the eTool office as well as in a webinar format to accommodate those outside of Australia.

Course Overview
eTool’s eToolLCD Assessor Lite training is designed to provide a a comprehensive understanding of of LCA methodology as well as a basic understanding of how to conduct an Life Cycle Assessment using eToolLCD. In this training you will be guided through your own practice project through to “certification” level to ensure a full understanding of the concepts and software. Upon completion of eToolLCD Assessor Lite training, you will have firsthand experience conducting an LCA as well as an overall undestanding of life cycle assessment of the built form. Ongoing support will be provided through your next project as required, at mutually agreeable times, to get your project to “certification” level. Upon completion of this second “certified” project, you will be awarded “Assessor Lite” accreditation.

Date: Please see this page for full dates
Location: 40-44 Pier Street, Perth WA 6000
Webinar: Attendees will be sent a GoToMeeting login the week of the event
Your trainer: Richard Haynes – eTool Co-Founder and Lead Software Development
Cost: $2,200 (incl GST)*

*This cost covers the 2-day training as well as one “certified” project.


Content

Day 1

  •  Aims of eToolLCD Software, eToolLCD History
  •  LCA Basics
  •  eTool Project Tree (including impact categories)
  •  Entering and Editing
    • Project
    • Buildings (with explanation of design life algorithm)
    • Design
  • Templates:
    • Templates Library
    • Viewing, adding cloning and creating Library Templates
    • Adding Templates to Designs
    • Custom Templates (within a design)
  • Low Carbon Design Principles and Demonstrations:
    •  Building Design Life and Effect on Embodied Impacts
    • Low Carbon Materials (and the thermal mass trade off)
    • Assembly, transport and travel impacts
    • Recurring impacts (maintenance)
    • Operational Energy Efficiency
    • Renewable Energy

Day 2

  •  Overview of Advanced Features
    • Nested Templates
    •  eTool Expressions Wizard
    • Custom grids, equipment and materials
    • Cloning a Design for Improvements or Scenarios
    •  LCA Reporting
    •  Submitting for Certification
    • The Future for eToolLCD Software

 

Future Grid Sensitivity

Context

The standard assumption eTool makes when conducting an LCA is applying the current emission factor of the electricity grid for the specific region over the life of the building. While renewable energy source do not currently make up a large percentage of the energy grid, the cost of renewable technologies has fallen dramatically over recent years. The Australian government also has a legally binding obligation to reduce its emissions by 5% on 1990 levels, under the Kyoto protocol. The Australian government has also committed to an 80% reduction by 2050.

If the decreasing cost of renewable energy trend continues and becomes competitive with coal and gas, the market will naturally shift away from fossil fuels, particularly if fossil fuel subsidies recede. There is also a small but growing consumer demand for more ethical electricity tariffs. This shift of energy sources into the electricity grid opens a potential for a change in the way grid emissions are calculated with life cycle assessment.

Modelling Decarbonisation

Presently in eTool we assume that the grid fuel mix remains at today’s levels for the life of the building. Whilst this is a good conservative position, and drives the right behaviour in terms of energy efficiency, it may divert some focus from other areas of the building, which may be more important if a more realistic future scenario of grid electricity impacts are used.

In response, we have created two other grid emission factors: a 2050 grid and a 2030 grid. The 2050 grid assumes an 80% reduction in the current grid intensity. The 2030 grid takes the average grid intensity over the next 40 years, assuming a linear move towards 80% renewable generation by 2050. The modelled reduction in CO2e intensity is achieved by:

  • Eliminating the most carbon intensive fuels from the current Australian electricity mix and replacing these with a combination of renewable sources, and
  • Increasing the thermal efficiency gas powered generators from 34% up to 50% (implementation of combined cycle turbines)

The fuel mixes and assumed thermal efficiencies for the different grids modelled is shown in Table 1. There are a few flaws in this method that we need to declare: Firstly, the scenarios assume reductions in CO2e intensity of tailpipe emissions only. It does not account life cycle emissions for electricity, which includes impacts associated with fuel extraction and transport upstream from the power plant as well as downstream impacts associated with transmission and distribution. Secondly, if we accepted that this would be enough to meet the 80% reduction in emissions required, the demand for electricity (or energy in general) could not increase. If there is an increase in demand, we would need to further reduce the intensity of Australian emissions and the target is on absolute GHG pollution, not pollution per dollar of GDP, per capita or per kWh. Nevertheless, we think the approach is suitable for the purposes of illustration and discussion, which is the goal of this technical article.

table

Table 1: Modelled Grid Fuel Mixes

Life Cycle Impacts of Residential Buildings

The graph below illustrates how the lower grid scenarios impact on a single residential dwellings life cycle emissions.  Proportionally, embodied emissions have a much larger impact than operational as the grid de-carbonises.

annualised GHG

 

Reconsidering Design Decisions

Generally speaking, there will be a move toward electric based solutions as the grid de-carbonises and the impacts of electricity become competitive with gas. A few recommendations that we typically apply to residential dwellings are shown for the different grid scenarios below.

Design decisions

In this instance, the annual CO2e savings associated with PV have more than halved in the 2050 scenario. Savings from embodied impacts in materials become much more important as the grid decarbonises and materials make up a larger proportion of a buildings CO2e. Moving to fly-ash concrete or replacing carpets gives greater savings than installing a gas hot water unit, which under todays grid scenario would ordinarily provide significantly more.

It’s important to note is that while the transition to a low carbon grid will likely occur incrementally over the coming years, the embodied impacts of the materials are locked in from the day of manufacture. Providing that the grid does decarbonise, material choice can be considered to be equally as important as operational energy, especially when dealing with buildings with a long design life.

What about the gas grid?

We have yet to add a CO2e intensity for future gas grids but watch this space.  There is potential for a reduction in the gas grid emission factor with more input into the gas grid from landfill collection and anaerobic digestion. Then again, potential impacts of shale gas fracking will also need to be considered.

The technologies that make up a dwellings services (cookers, boilers, heat pumps etc.) typically have a lifespan of no more than 20 years. Our approach at eTool remains to recommend the lowest carbon solution based on today’s grids with the assumption/hope that they will be replaced with whatever the lowest carbon solution happens to be in 20 years time.

The future may also bring an appropriate price on carbon and studies show that $150+/tonne reflects the true cost of climate change (social and economic cost), which will drive behavior. For example, a gas hot water system is significantly lower in carbon emissions today but in 20 years time when it is replaced, the electricity grid may have decarbonised such that a heat pump is now the low carbon option. Perhaps the occupant will be further incentivised by the price of a renewable electricity grid versus finite gas with a high carbon price.

What about Materials Future Impacts?

The manufacturing of some materials will decarbonise over the coming years, such as the use of biomass in the heating processes in cement production. However, for a building constructed today, the key structural elements of a building such as the impacts associated with the concrete or steel are locked in on the day of construction. The recurring impacts of replacing high carbon materials like plasterboard and carpet may also decrease as the economy de-carbonises. For some elements, this may be due simply to using renewable electricity in the manufacturing plant. For others it may require something more innovative such as developing sheep food that does not make them burp and fart.

There is a high level of uncertainty associated with future impact intensities for the system processes and materials making up a buildings use phase. For example, as Australia’s economy de-carbonises, the impacts associated with energy inputs, maintenance, replacement, repair, water use, and transport will likely decrease (particularly with regard to global warming potential). This has not been accounted for in the analysis. One could potentially model the effects of this parameter on GWP alone as we do know Australia’s current commitments to reduced greenhouse gas emissions, however, even this is very speculative as we do not know how the economy will decarbonise (through efficiency, reduced growth, alternative fuels, renewable energy sources or other mechanisms). The building energy inputs, and the fuel mix for manufacturing products used through the building life span has therefore been assumed constant, and set at today’s values throughout the modelled life cycle of the building.

What else might change?

Australia has been seeing first-hand the effects of climate change for a number of years. The meteorology department has confirmed that 2013 was the hottest year on record experiencing a greater number and intensity of heat waves than ever before. Even if global CO2e emissions are kept within the threshold for a 2 degree global rise in temperature, we will still need to adapt to the climatic changes that have resulted from our current emissions. The Garnet Institute makes the following predictions regarding changes to climate in Perth assuming no mitigation:

garaut

–          4 degree rise in average temperature in Perth,

–          56% increase in number of days over 35 degrees by 2070

–          15% – 45% reduction in rainfall in Perth by 2070

–          15 – 65% increase in number of days with “Extreme fire risk”

 

In the best case scenario with emissions stabilising at 450 ppm, there is still a 2 degree rise in average temperature across most of Australia. The reality is that we have already passed 400ppm and 550ppm (3 degree rise) is realistic. To adapt to these changes we will see a greatly increased use of air conditioning across all building types to maintain thermal comfort.

 

-Researched and written by Pat Hermon 

 

Research Sources

  1. http://www.therenewableenergycentre.co.uk/solar-heating/
  2. http://www.home-energy-metering.com/solar-thermal-energy.html
  3. http://www.garnautreview.org.au/chp5.html

 

 

GBCA Green Star 2014 Incorporates LCA Credit

Last year, the Green Building Council of Australia (GBCA) announced the launch of two Life Cycle Analysis (LCA) based “Innovation Challenges”, which challenged the industry to incorporate Whole of Building LCA (6 points), and Environmental Product Declarations (EPDs) (2 points) into new and registered Green Star projects.

Just this month, GBCA released their Summary of Changes to Credits report where life cycle assessment is now a draft credit offered for Green Star. The newly added Material Life Cycle Impacts credit makes up to six points available for whole-of-building, life cycle cycle assessment:

  • 4 points for realising an improvement across six environmental impact categories in comparison to a theoretical benchmark building
  • 1 additional point available for including an additional five impact categories in the analysis

This is exciting news for life cycle assessment as it signifies the growing global trend towards LCA as the preferred design and assessment method for sustainable buildings. Just last month, the Urban Development Institute of Australia (UDIA) also embraced life cycle assessment in their EnviroDevelopment standards.

eTool is a leader in life cycle design and assessment through our innovative, sophisticated life cycle assessment software and consulting services and offer a range of services to best suit your needs. Please contact us if you have any queries about the new LCA Green Star credit or if you would like to discuss how eTool can assist with your Green Star project.

Watch this space as life cycle design continues to soar and eTool congratulates GBCA for another positive development in Green Star.

 

 

LCA Design Life and Functionality

Why This Post?

Well, it turns out it’s REALLY important. My eyes opened to this on the first life cycle assessment we conducted four years ago now. I probably didn’t realise how important it was until more recently though.  The crucial moment was when we did some back of the envelope, top-down carbon budgeting to understand how much greenhouse pollutions our buildings could push into the atmosphere and still enable a stable climate. And this is where it gets interesting. The workings to our rough carbon budget for buildings are here and they throw out a fairly large challenge. In fact, for residential buildings, we need to go net zero operational carbon, and then reduce the remaining embodied emissions by nearly 90%.

Often when you hear the term embodied energy, embodied carbon or embodied impacts, it’s associated with materials choices. Or at least that’s the normal approach to reducing embodied impacts. But there’s an elephant in the living room that’s not being addressed, and this post discusses that. If you don’t want to read about it, sit back and enjoy this video (apologies for the less than professional sound quality).

 

Some LCA Basics

Life Cycle Assessment isn’t just about measuring impacts. One of the key elements of ISO 14040 is to consider the “Functional Unit” of the object of your assessment. The functional unit enables comparisons between variations of the product or services. In the case of buildings, it would correct for things like design life and size. Inherently, it’s correcting for the function of the building. And the formula for the impacts of a building hence becomes:

Life Cycle Assessment Impact Equation for Residential Building

Life Cycle Assessment Impact Equation for Residential Building

As mentioned above, most people focus on reducing the impacts when trying to improve building environmental performance. In reality though, it’s the denominator that often has the most effect on the impact of a building. And this stands to reason. If your building houses more occupants, or lasts longer, it’s providing more benefit for the same initial and disposal impacts (construction and demolition).  As mentioned in a related post here, we actually need to reduce our embodied emissions by nearly 90% to hit a sustainable level of GHG emissions.  So we need every bit of help we can get, and some focus on functionality and design life presents us with some very low hanging fruit.

Design Life

Extending design life is a brilliant way of improving the impacts per functional unit for a buildings. This is because most maintenance, energy and water inputs are pretty constant over the building’s life, where as the initial materials, construction, demolition and disposal impacts are quite independent of design life. For residential buildings in Australia, for example, these initial and end of life impacts total approximately 25% of the total life cycle impacts. So, by doubling design life without any change to energy efficiency, you can reduce the overall impacts of your building by over 12%.

How to Influence Design Life

In order to answer this question we really need to think about what is driving demolitions. There are two good surveys that answer this question quite well. One is from the US and the other Australia. They compliment each other in their answers. Here are the results:

US Study Conducted By Athena:

Reason for RedevelopmentProportionCategorised ReasonProportion
Area Redevelopment35%Not Related to Durability61.3%
No Longer Suitable for Needs22%
Code Compliance Too Expensive2%
Socially Undesirable Use1%
Maintenance Too Expensive0%
Changing Land Values0%
Out Dated Appearance0.90%
Lack of Maintenance23.80%Lack of maintenance / neglect26.4%
Other Physical Condition2.60%
Structural or Material Problem3.50%Durability Issue3.5%
Other2%Other8.8%
Fire Damage7%

Athena, Demolition Survey – Building Service Life Study – Phase Two

There seems to be a surprisingly large proportion of buildings that are being redeveloped for reasons other that structural integrity. So, building strength and durability seems to be only part of the design life story. It gets a lot more interesting when you read this study further, as it turns out the longest lasting buildings are actually timber. This was counter intuitive to me, I would have expected the steel and concrete buildings to be lasting longer than the timber ones. The other interesting thing was that there seems to be a hump that a building needs to get over at the 30-50 year mark, and once it’s over that, it’ll last a long time.

Service Life of Structure Type

 

The Australian survey supports the theme that durability is only part of the story.

Reason for RedevelopmentProportion
Demolished for Site Redevelopment58%
No Longer Suits Owners Needs28%
Other6%
Building Becomes Unserviceable8%

Dynamics of Carbon Stocks in Timber in Australian Residential Housing

Redevelopment Probability

These studies suggest that the durability of a building only plays a small role in predicting service life. Other factors, predominantly redevelopment pressure, are actually more important. The strategies to counter this are relatively simple. I’ve listed a few below:

  • Increase density compared to surrounding suburb through:

– Building value : Land value ratio
– Maximise yield

  • Diversify lot ownership, which increases difficulty for redevelopment in the future
  • Design quality (create timeless character by ensuring house is designed for the site and surrounds)
  • Enable retrofitting (enable occupant density to be increased or building use to be transformed easily without demolition)

Other strategies that assist in extending the service life of the building (or materials) include:

  • Ensure appropriate materials are used to weather any likely natural disasters in a region (e.g. fire)
  • Where redevelopment potential is very low, focus construction methods
  • Design for deconstruction (extend materials service life beyond the building)

We should be thinking of buildings as permanent features, that may stand for many centuries. Whilst this would be a paradigm shift in Australia, there are countless examples of suburbs within the world’s major cities where average design life of existing structures would be well in excess of 100 years. These are cities like London, Paris and Rome where this resilience to redevelopment is in itself the appeal of these cities. There are still pockets of historical buildings in Australian cities also, and our aim should be to promote this approach to the extent that it become the norm.

Functionality

Increasing functionality is perhaps slightly simpler. It does require buy-in from the owner. In the residential context it really comes down to increasing occupancy within the same space. This doesn’t necessarily mean sacrificing life-style. Very well considered design will yield efficiencies in ensuring that every square metre of floor space is well utilised. Integration of stairs, corridors, studies, entertainment areas etc into bedrooms or living rooms are examples of efficient design. It also pays to compare our current residential functional average to that of our past, and also other countries. The chart below shows that over the last 35 years, Australia has trended badly in terms of environmental sustainability in relation to functionality of residential buildings. During this period, the average size of new buildings has significantly increased, whist the occupancy per dwelling has dropped. It’s encouraging to see a recent reversal in this trend, and we hope it continues.

Australian Residential Building Functionality TrendsWhen we look at he space per person, it’s increased from 54 to 96 square metres.  Compare this to the average space per occupant in the UK of 32 square metres and it’s clear that we have some wiggle room in this area.

In commercial buildings, there’s very good financial incentive for improving floor plate efficiency as it means greater rent. Small changes can yield big uplift in rental revenue. Intelligent strategies to improve floor plate efficiency include:

  • Sharing services between floors
  • Optimising lift size, speed and number
  • Minimising services risers
  • Minimising circulation ways

The common areas associated with large apartments or office buildings are also very worthy of attention. In Australia particularly, car parks often amount to 25% of total floor space or more. This is a huge burden on the useful floor area of the building, not only in terms of embodied impacts, but also operationally, due to lighting and ventilation requirements. Currently, car park efficiency is an area that doesn’t receive a lot of attention. We have yet to see a design brief where a developer has stipulated a target floor area per car park. Good practice internationally is 20 square meters per car space, and this is with a normal 90 degree layout. If the car park is large enough to accommodate loop, by moving to 45 degree angle parking the space requirements can be reduced even further. This is enabled by reducing the required space to pull in and out of the park to a single lane for 45 degrees nose-in parking, whereas 90 degree parking requires two lanes. It’s not uncommon to see car parks in Perth buildings requiring 30 square meters of space per car park, so there’s huge potential in this area for efficiency improvements and cost gains. Could that three level basement car park be optimised and reduced to two? Ask the question and refer to some international benchmarks on car park design, you might be pleasantly surprised.

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The most frustrating thing about all these great opportunities to improve a building’s design life or functionality is that we rarely get to help people do it. The reason is, it’s usually been designed by the time we’re engaged. There’s a nice chart, a version of which is below, that explains how as a project progresses from brief to concept to construction and onwards, the ability to influence it’s environmental performance drops off sharply. This post effectively explains a bit part of the reason why. There are other design opportunities that also need early consideration to become feasible as well. We recognised this pretty early on at eTool and developed way of running ‘scoping study’ LCAs to help design teams identify and reduce environmental impact ‘hot spots’ in their concept designs. We’ve taken this a step further now by offering a target setting service. We can help a design team develop performance targets for their building before a concept design has even been dreamt up. All we really need is a draft brief and we can profile the life cycle impacts of a normal approach to delivering the intended function of the building. We then use this model to simulate improvements that the owner and design team want to target, these can include design life or functionality improvements. Early feedback on this service has been great, get in touch if you want more information.

Building Life Cycle Environmental Influence

 

 

 

 

A Rough Carbon Budget For Buildings

Why A Carbon Budget?

As we learn more about greenhouse (GHG) pollution and global warming we’re getting better at understanding cause and effect. There’s lots of complexity, obviously. However, the variables are slowly being identified, tested, and fed back into the models. Last year the media latched onto a story that global warming had ceased. I wish the stories indeed did debunk climate theory. Unfortunately not. We’re just in a period of warmer oceans and cooler atmosphere. Will Steffen explained this in a very objective manner when questioned in the Senate Committee on Extreme Weather Events (see page 12 of this transcript). Anyway, all the scientific research into climate change now enables us to make predictions of warming based on the volume of GHG we release into the atmosphere. And we’re even able to make predictions about what effects this may have. The below infographic is an incredibly good summary of these predictions, and the background data is rock solid if you’re interesting in looking into this further.

KIB_Gigatons_CO2_Apr14_A4

 

It’s pretty clear we need to try to limit warming to two degrees. The big reason for this is that there are tipping points for our climate, which trigger events that force more warming. Some examples include melting of arctic tundra and stored methane, release of methane from sea bed methane clathrates or the collapse of the amazon due to drought and fire. We don’t actually know at what point these events will happen and they may even happen before we get to two degrees warming. What we do know, is that it’s highly likely they will happen if we keep warming the planet. Even without these events occurring, we’re on track for four degrees of warming by the end of the century. Four degrees will probably put so much pressure on food resources there’ll be major global conflict. Not over land, or oil, but over food. It could get very messy.

A Per Capita Carbon Budget

So, we need to work out how much more carbon we can release to avoid these events, we need to set a budget. There is actually a level of GHG pollution that the planet can happily cope with naturally through chemical and biological sequestration. It’s a rubbery number, but sits at about 2.0 tCO2e per person. In 2050, accounting for population growth, we really need to be aiming for approximately 1.0 t CO2e per person per year which would actually enable us to reduce the GHG in the atmosphere. This, then, is our sustainable level of GHG emissions on a per capita basis. Some calculations on this here and here (with slightly different results).

Apportioning to Economic Sectors

Relating this to buildings is a little difficult because we don’t really know how the economy is going to decarbonise. There might be breakthroughs in certain sectors that enable it to effectively zero its GHG emissions, whilst others may find it very hard to shake the existing thirst for fossil fuels (or land use change). If however, we assume that all major sectors of the economy decarbonize together, then we can essentially take each sector’s current percentage of GHG emissions and multiply it by 1.0 t CO2e to yield the per capita budget for each sector. This is one of the best diagrams I have come across to explain GHG flows through the economy. It’s taken from a great publication called Navigating the Numbers.

GHG Flows

GHG Flows

In the diagram, the column “end use activity” is what we need to focus on to determine how current GHGs are apportioned across our economy. Directly, buildings are responsible for 15.3% of GHGs. However, there are a lot of indirect emissions that relate to buildings if you take a life cycle approach to measuring an impact of a building. These include transportation of materials to the site, transportation of equipment and labour, construction energy, emissions relating to materials production, further transport, and equipment use to maintain the building. Then deconstruction, demolition and landfill emissions. There may also be land use change emissions associated with some building products, or urbanisation as well. If we make the below assumptions regarding the allocation of these indirect emissions to buildings (which are not based on research, but I believe are reasonable), we land at a number of 26% of total GHG emissions relating to buildings.

  • 60% of building energy use relates to electricity to determine distribution and transmission losses
  • 70% of coal is used for electricity or downstream processes attributed to buildings
  • 30% of oil and gas gets used for electricity or downstream processes that can be attributed to buildings
  • Unallocated fuel combustion is proportionally attributed to all end uses
  • 1% of air transport and 10% of all other transport relates to building construction, maintenance, design or management.
  • 50% of iron, steel and cement is used in building construction or maintenance
  • 10% of chemicals are used in building construction or maintenance
  • 25% of aluminium and non ferrous metals are used in building construction or maintenance
  • 10% of other industries are providing materials or services to building construction or maintenance
  • 25% of land use change emissions due to harvest and management of forests relate to construction and maintenance of buildings
  • 15% of all landfill gas emissions relate to disposal of construction waste
  • 75% of waste water treatment emissions relate to building waste water

Building Related Emissions

These assumptions and calculations at this point are moving pretty quickly towards “back of the envelope”. The only way I can really justify this is that there are no numbers out there telling us what is a sustainable level of GHG emissions for buildings. So don’t hang your hat on these numbers, however, in lieu of more robust calculations, here’s a starting point.

A Carbon Budget For Buildings

We can now set a rough carbon footprint for environmentally sustainable buildings at 260kgCO2e per year per capita. This will be split between residential dwellings and other buildings. If we assume the split is the same as the direct GHG split in the “Navigating the Numbers” flow chart, that gives us a budget of 168kgCO2e per year per capita for residences, with the remainder of building related GHG distributed to workplaces, hospitals, civic buildings etc. We haven’t done any work on how to distribute the remainder amongst these other buildings as it gets pretty complex but watch this space. For residential buildings in Australia, we have a lot of work to do to achieve this budget. See the below chart for a visual on that.

Australian Residential Buildings

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Although these numbers require more work to confirm, they provide some guidance in lieu of other sources. They display the extent of the challenge. In particular, note in the last chart that the target is many times less than even the embodied GHG of current “average” buildings in Australia. I extend on this topic in this post, exploring some lateral thinking to solving the challenge of hitting our carbon budget for buildings. Note, this is an update on the video attached to the next post so you may spot a difference in the figures.

 

 

Edge by Psaros Wins International Property Award

Perth property developer and a long standing client of eTool, Psaros, was awarded one of the 2014 Asia Pacific Property Awards for their most recent development, ‘Edge by Psaros’. Edge by Psaros  is a 96 unit sustainable development located in Northbridge. It incorporates renewable energy technology, clever energy efficiency measures for individual homes and common areas and a long design life.

Check out this video to see what Psaros CEO, Danny Psaros and City of Perth Lord Mayor, Lisa Scaffidi have to say about it: