SUSTAINABLE RETROFIT IN THE
MELBOURNE CBD:
CONTEMPORARY PRACTICES.
Sara J Wilkinson
Overview
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The context and rationale
The policy environment
Existing buildings and sustainability
Retrofit issues
Research aims and methodology
Results and interpretation
Where to next …………………..
The context and rationale
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Retrofit of the existing stock is essential to mitigate global warming.
Most stock has no consideration of sustainability.
Legislated in the BCA in 2006.
In 2005-6 commercial buildings were responsible for 53% of all
greenhouse gas (GHG) emissions in the Melbourne CBD (City of
Melbourne 2008).
• 87% of the stock we will have in 2050 is already built.
The policy environment
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Is changing.
Melbourne 2020 - 1200 Buildings.
Sydney 2030 and others …..
Melbourne 2008 – 1800 commercial building Arup report 38%
reductions possible.
• Sustainable Melbourne Fund – Environmental Upgrade Agreements
(UEAs).
• Mandatory Disclosure 2010 – 2000m² + NABERS rating required.
Existing office buildings and sustainability
Existing office buildings and sustainability
Existing office buildings and sustainability
Retrofit issues
• economic, location and land use, physical,
legal, social and environmental
Research aims
• To gain a deeper understanding of the
sustainability improvements made to existing
office buildings in the 1200 Buildings Program
in Melbourne, Australia.
• To undertake a comparison of current practice
to identify similarities and differences to
retrofits in the 1200 Buildings Program.
Research methodology
• Study involved the analysis of words to examine practices regarding
sustainable commercial retrofit in the 1200 Buildings Program. A
quantitative approach was unsuitable - too few events (Silverman,
2000).
• Exploratory research to identify what is undertaken was achieved
through a content analysis of completed projects. (10 projects).
• Interviews provide deeper and richer data - not possible to trace all
those involved.
• Case study can be exploratory or explanatory (Robson, 2003). The
analytical strategy is partially explanation building and partially
pattern matching to previous patterns of building retrofit practices
in the Melbourne CBD.
Results and interpretation
Age (years)
Figure 1 – Case study building age and address.
Case
131 Queen St
636 Bourke St
247 Flinders
La
490 Spencer
St
500 Collins St
406 Collins St
Objectives
Make safety and essential services code compliant.
Achieve to a 4/ 4.5 NABERS rating.
Reduce running costs.
Develop an environmentally efficient building in the use of energy and water.
Minimise noise transfer in and around the building.
Achieve a minimum NABERS 4 star.
Create a zero GHG building
Achieve A-grade building.
Attain high environmental efficiency.
Maximise tenant retention during upgrade to maintain optimum cash flow and provide pool of
long-term tenants.
Elevate tenancy profile by increasing the average size of tenancy, length of tenure and quality of
tenant achieve a justifiable ROI.
Improve energy efficiency.
Achieve a 4 star NABERS energy rating.
Reduce carbon footprint and use green power sources.
Reduce carbon footprint.
182 Capel St
Reduce carbon emissions by at least 50%.
Attain a 4.5 star NABERS Energy
115 Batman St Introduce state of the art engineering services with very low levels of energy consumption.
Provide comfortable working environment to enhance productivity
Achieve 5 Star Green Star and 5.0 star NABERS Energy ratings.
385 Bourke St
Achieve 2.5 NABERS Energy rating.
530 Collins St Achieve a 4.5 star NABERS Energy rating.
• 70 measures were implemented.
• Environmental and social.
• Many environmental measures implemented due to potential economic
benefit.
• Most measures, 61%, related to building services.
• 73% related to energy efficiency.
• Water economy measures featured less (11%).
• Measures to fabric were associated with energy efficiency - less frequent
(17%), involve access challenges, disrupt occupants, and are expensive.
They offer a longer term solution than upgraded services which require
maintenance and are replaced within 20 years.
• Social sustainability featured in 4 cases (amenities provided to users in
respect of improved IEQ).
• 6% had a social sustainability component. (a roof top garden for social
space, however rationale included environmental benefits of reducing the
UHI effect, insulating the roof and reducing energy use (economic benefit).
One project featured housed small businesses driven by social justice and
equity issues; having a positive social sustainability contribution.
• Overall social sustainability has a lower profile.
Physical issues - not related to fabric performance though acknowledged as important the
costs are higher. Reflects the current economic climate and timeframe for ROI. Other
physical factors were hostile factors such as construction noise disrupting tenants in situ.
Economic objectives were met in many cases with energy and water costs reduced,
maintenance costs reduced in all but one case, higher rents recorded and yields achieved.
In two cases there were concerns regarding ROI and these projects relied on Green Building
Grant for viability.
Environmental outcomes were achieved and exceeded in some cases NABERS ratings
exceeding targets. Energy and water use was reduced in all cases and one is zero carbon on
sunny days.
Social outcomes positive with higher productivity and improved IEQ measured in one POE.
Staffs were ‘happier’ in the post retrofit buildings. Green roof worked well and the hotel
building attracted some on the basis of ‘green’ credentials.
Management issues were difficulties of getting multiple owners to agree, the need to
communicate effectively with and educate tenants, the need for strong PM, the need for
advocates to promote ESD and for independent commissioning agents to verify data.
Retention of tenants was positive. In some the aim to increase occupancy was achieved.
More generally;
Owners motivated by different drivers; predominant initiating party was BE consultants.
Fringe locations featured more prominently compared to general trends and earlier studies
(Wilkinson 2012) however low prime is where most retrofits occur and this compliments earlier
study and general practices.
In the 1200 Building Program preference is for non-heritage buildings confirming the additional
requirements for adaptation may deter owners from adapting.
Ungraded buildings were most likely to be retrofitted (50%), followed by B grade (20%) -1200
Buildings Program is reaching all grades of stock which is vital if all stock is to be adapted.
Substantial improvements afforded in terms of energy efficiency. Snyder’s (2005) finding that
there is a relationship between proactive legislation and change in the adaptation market is
supported; here the realisation is buildings with enhanced sustainability.
Thank you for listening – any questions?