Back to the future: Harnessing Building Information Modeling for Greening Retrofit Projects

Amid the international push towards sustainability and energy efficiency, retrofitting existing buildings into greener models is a crucial strategy for reducing the consumptive effect that the built environment has on its surroundings. Buildings typically account for 40% of a city’s total energy usage, with electricity in the built environment accounting for nearly a quarter of South Africa’s carbon emissions. Retrofitting existing structures can thus play a significant role in infusing the built industry with environmentally-sustainable solutions.   

29 Feb 2024 3 min read Construction & Engineering Alert Article

At a glance

  • The built environment has a consumptive effect, with buildings typically accounting for 40% of the total energy usage in a city. Retrofitting existing structures into greener models is a crucial strategy to pursue sustainable architectural solutions.
  • Within the construction framework, Building Information Modeling (BIM) could serve as a potent tool to rejuvenate older structures into more environmentally friendly models.
  • While many existing buildings lack BIM integration due to cost constraints and technological limitations, South Africa has attempted to make such standards more accessible.

The retrofitting process entails a physical and functional refreshment of an existing building by adding new features or technologies to it. This is especially useful to monitor and improve energy consumption levels. Since 60% to 75% of a commercial building’s primary energy use arises from heating, ventilation and cooling systems (HVAC), as well as poor lighting options, opting to perform necessary HVAC upgrades and substituting fluorescent tubes and halogen bulbs for LED globes is a meaningful start for a greening project.

The success of using retrofitting to reduce a building’s greenhouse gas emissions and energy consumption is aptly demonstrated by the Empire State Building. This retrofit project formed part of a $550 million restoration programme, where more than 6,500 windows received additional layers of film to regulate heat gain and loss. Its elevator system now uses regenerative braking that recaptures electricity as the cars decelerate and reach their destinations. This feeds energy back into the building. From its automated LED lights to the refurbished steam room in the basement, the changes made to this century-old building have reduced its energy consumption by more than 40%, allowing for annual energy savings of $4,4 million since 2010.

Within the construction framework, Building Information Modeling (BIM) could serve as a potent tool to rejuvenate older structures into more environmentally friendly models. BIM provides a digital representation of a building’s physical and functional characteristics, storing its data throughout its life cycle and tracking energy usage. Its collaborative nature facilitates easy access to a building’s history, enabling predictive maintenance, allowing for efficient procurement, and making subsequent greening efforts manageable by allowing for comparative views on past versus prospective energy use in the building.

South Africa’s adoption of BIM standards

While many existing buildings lack BIM integration due to cost constraints and technological limitations, South Africa has initiated the national adoption of international BIM standards (known as ISO 19650). According to the Standards Act 8 of 2008, SANS 19650-3:2023 shares a parallel aim to ISO 19650: to optimise the information management of built assets using BIM. The South African Bureau of Standards (SABS) divides the SANS 19650 series into three parts, starting with an explanation of the concepts and principles of information production and management through BIM use.

Part two aims to enable a party to establish the requirements for information during an asset’s delivery phase and to provide an optimal commercial and collaborative environment, in which appointed parties can produce information in an efficient way. Part two also contains the National Annex, which comprehensively demonstrates how the international standard will be adopted in South Africa.

Part three contextualises how information must be managed and exchanged during the operational phase of assets. Parts one and two have been issued, while part three is expected to be approved shortly, after public comment closed on 25 May 2023. Adopting ISO 19650 on a national level renders BIM standards more accessible.

Such regulatory development can not only result in short and long-term cost preservation for companies through effective digitised building planning, but can further extend the “measure twice, cut once” principle, by having companies simulate construction and operation processes virtually, thus minimising errors and environmental impacts in the physical realm. In light of the International Finance Corporation’s estimate that South Africa’s green building demand will be an investment opportunity of $7 billion by 2030, the integration of BIM standards is foundational to further fiscal development.

In conclusion, BIM must be adopted today to enable the greening and retrofitting benefits of tomorrow. South Africa’s regulatory landscape in this regard is still nascent in comparison to countries like the UK and US, which have already mandated BIM to varying extents. However, with the issuing of SANS 19650 in its respective components, it is advisable for construction companies to prioritise engagement with BIM-accredited consultants. There is also a need to expand the cohort of ISO 19650-knowledgeable practitioners, for the effective implementation of the standards, industrial development and environmental stewardship.

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