Retrofitting vs demolition: Which is more sustainable for buildings?
In 2010, the Building and Construction Authority (BCA) published a guidebook called Existing Building Retrofit. It emphasised the importance of retrofitting as a tool to help meet Singapore’s goal of greening at least 80% of its buildings by 2030. In the city-state, the trend is to demolish and rebuild. “This pattern is simply not sustainable for the future as it requires huge amounts of resources that are becoming increasingly rare, thereby wasting a large amount of embodied energy,” BCA commented in the book.
Joelle Chen, head of sustainability, Asia, at Lendlease, concurs. “Singapore has made good progress. But in order to close the gap between now and 2030, we need to start retrofitting more buildings,” she says.
The fourth iteration of the Singapore Green Building Masterplan (SGBMP), launched in 2021, has set targets of “80-80-80 in 2030”: greening 80% of Singapore’s buildings by gross floor area, having 80% of new developments as Super Low Energy buildings, and achieving 80% improvement in building efficiency for best-in-class buildings — all by 2030.
To accelerate the pace of retrofitting, BCA launched $63 million in fresh funding for the Green Mark Incentive Scheme for Existing Buildings (GMIS-EB) scheme last June. This is to encourage building owners to aim for the highest rating in sustainability — a Green Mark Platinum, Super Low Energy or Zero Energy rating. The BCA had introduced the $100 million GMIS-EB incentive scheme in 2009 to help fund retrofits to improve an existing building’s energy efficiency.
Improving sustainability
According to Minister for National Development Desmond Lee, 49% of Singapore buildings have been greened. However, many more of the older buildings need to be retrofitted to improve their sustainability standards, he said in a July 2022 speech.
Retrofitting means to refurbish an existing building to make it more efficient. “At a minimum, a building will likely be retrofitted every 15 to 20 years to replace things like its chiller plants and air-conditioning systems as they reach the end of their lifespan,” says Lendlease’s Chen.
In addition, building owners are incentivised to replace such systems as the replacements can result in significant energy cost savings. Chen estimates that a building could see between
10% and 20% energy savings by retrofitting its chiller plants and switching to LED lighting. “There’s a clear return on investment for replacing active systems.”
Retrofitting covers all kinds of upgrades, whether they are aimed at reducing carbon footprint, generating more value, enhancing tenant experience, keeping up with building guidelines, and more, she adds. The upgrades range from simple ones, such as adding a solar film to a building’s windows to reduce the glare and heat that enters the building, to a major retrofit that could entail things like structural and façade alterations.
From a green perspective however, retrofitting is not always the more sustainable option, observes Chen. This is because carbon emissions need to be considered across a building’s life-cycle. Typically, about 25% of a building’s carbon cost comes from its construction (also known as embodied carbon). But the bulk, or 50%, of costs come from operational carbon, which refers to carbon emitted through the daily operation of a building. The remaining 25% comes from periodic changes such as replacing furniture and fittings.
‘Doing the math’
When considering whether to retrofit or rebuild, Chen notes there are multiple factors involved. “There is the commercial standpoint, but there’s also sustainability factors such as resource efficiency and embodied carbon reduction, as well as making sure the building is fit for its purpose.”
If a building’s age and specifications make it significantly challenging to implement operational improvements, demolishing a building and rebuilding may make more sense in the long run, notes Chen. This is especially true where reconstruction is done more sustainably, such as using a high proportion of recycled raw materials, opting for cleaner construction methods, and using biodiesel to power construction equipment.
For example, SingTel announced last year that it has partnered Lendlease to redevelop its Comcentre headquarters in the Somerset area of Orchard Road. The new tower will be a $3 billion “world-class sustainable workplace” featuring the latest in smart building technology. New York-based Kohn Pederson Fox is the design architect.
According to Chen, the new Comcentre is slated to be Singapore’s first end-to-end carbon-neutral development across design, construction and operation. Over its lifespan, the net-zero development is projected to reap energy savings of 9.9 million kilowatt-hours.
Building owners need to understand what they want in their building and figure out how the numbers stack up, she adds. “It’s about doing the math, and seeing what makes sense.”
The same approach underpins the redevelopment of the former Certis Cisco Centre into Paya Lebar Green, which is being undertaken by a 50:50 joint venture between Certis and Lendlease. For this project, one of the buildings will be retrofitted while the other has been torn down. The site’s use will be intensified, with the former seven-storey building making way for a new, 12-storey, Grade-A office building.
Whether retrofitting or redeveloping, both lead towards the same goal: to ensure a building effectively serves its purpose. “Buildings are meant for people,” Chen says. “They should provide a good experience for those spending time there.”