What is a Zero Carbon Building?

What does “Zero Carbon” mean?  We thought we’d post this for clarity, when eTool make a claim about one of our subscriber’s (or client’s) buildings we aren’t cutting corners. When we use phrases like “Zero Carbon”, “Low Carbon” etc we’re talking about the Life Cycle Emissions of the buildings.  The normal scope is summarised in the following system boundary diagram (which also works pretty well for infrastructure as well).


eToolLCD System Boundary

eToolLCD System Boundary

There’s a number of varying definitions for “Zero Carbon” in use.  In Europe (including the UK) it’s generally only inclusive of module B6 in the above diagram (that’s integrated equipment energy use in the building) which is very limited.  Some more detail on the varied definitions is available from these two downloads (there are a host more such studies / reports / articles on the internet, this is just a sample):

What is a “Carbon Neutral” Building? Light House Sustainable Building Centre Defining Zero Carbon Buildings – ASBEC

Defining Zero Carbon Buildings – ASBEC


eToolLCD Automated Reporting

We love Life Cycle Design and we want to make it attractive to everyone. We are driven on innovation and passion, and backed up by a constantly improving scientific approach.  We are always looking for ways to make LCD more mainstream and encourage greater uptake by the built environment sector.


Transparency is key to successful Life Cycle Design practice and we are very excited to announce eToolLCD now produces EN15978 compliant automated reports.  Yes, no more editing documents or tables outside the software to produce your final reports!


Our goal with eToolLCD and our community of software users is to achieve carbon reduction by allowing better understanding and consistent measurement of the whole life carbon emissions of built projects.

GWP Graph

GWP Graph

The automated reporting functionality was developed to comply with the widely accepted environmental performance assessment methodology EN 15978. We all know eToolLCD produces results in accordance with EN15978 but the automated reporting increases a standardized approach to its practical implementation and interpretation including:

  • Introduction
  • Goals
  • Scope
    • Functional Unit, System Boundary, Environmental Indicators, System Description, Cut off criteria, Allocation, Independent review
  • Inventory Analysis
    • eToolLCD software, Data quality, Completeness,
  • Life Cycle Impact Assessment
  • Life Cycle Interpretation
  • Conclusions
  • References
    • Background LCI Data, Inventory Design Documentation, Inventory Assumptions, EPDs
  • Appendix
    • Environmental Indicators Description, Detailed Structure Scope Diagram, Detailed Life Cycle Inventory

Click here for an example report

We are making Life Cycle Design easier for everyone so get in touch with us to start using eToolLCD or engage eTool as consultants on your next project.

HBF Arena – Life Cycle Costing

eTool was engaged by EMCO to conduct a Life Cycle Costing (LCC) study on the HBF Arena Upgrades located in Joondalup – WA. The design development report required a conclusive whole facility life cycle cost analysis showing cost elements to be budgeted for in each year of the planned project useful economic life.


The object of the assessment was the structure itself. eToolLCD software was used to model the LCC using available construction drawings. The assessment included all the upstream and downstream processes needed to provide the primary function of the structure from construction, maintenance, operation, and finally demolition and disposal. The inventory included the extraction of raw materials or energy and the release of substances back to the environment or to the point where inventory items exit the system boundary either during or at the end of the project life cycle.

LCC Diagram

LCC Diagram

The results of the life cycle model over the 50 year period showed little difference between the benchmark design and the concept design as both assume NCC compliant ‘deemed to satisfy’ thermal comfort measures. It was assumed that the concept design had slightly better energy consumption due to design features (like the extended roof) which should be of benefit. These design features were also reflected in the capital costs of the building design. The Low Impact design (assuming all low impact strategies are put in place) significantly exceeds the performance of the other designs modelled. This is due to energy cost savings which are significant (over $100,000) in the first year and expanding over time with inflation).

Opportunities – The study highlights a number of opportunities to improve the LCC of the buildings during the operational phase. These are summarised below:
• Care for the sprung floor in the sports hall to extend the life past 25 years.
• Care for other floor finishes (carpet and vinyl throughout) to extend their life.
• Care for the sports seating in the sports hall to extend life past 15 years.
• Ensuring energy is conserved by switching off lights and air conditioning in zones that are not in use.
• Ensuring building ventilation systems are deactivated when the buildings (or zones) are not in use.
• Minimise cleaning costs by spacing cleaning frequency, careful selection of service provider and setting high expectations of occupants regarding cleanliness.

eTool LCC is a whole of building, whole of life design approach aimed at improving the economic performance of buildings. The scope of the LCC model provides certainty that design decisions made with the aim of improving performance of one life cycle stage or component of a building don’t result on poor trade offs and net reductions in performance.