Building Preservation: Transforming the Legacy of the Past, into the Promise of Tomorrow

‘The Greenest Building Is… One That Is Already Built.’
– Carl Elefante AIA, LEED AP (2007) in The Journal of National Trust for Historic Perseveration, Volume 21 – No 4.

Elefante’s coined phrase poses great significance on building preservation today, despite his article being written 14 years ago.

Considering the world’s race to achieve NetZero carbon emissions by 2050, the construction sector is working to reform its practices and materials choices to reduce, and even reverse, harsh environmental impact caused by the sector and built environment. Throughout his article, Elefante questions what is truly sustainable and highlights the importance of preservation, shifting the focus on aging building stock that makes up a significant proportion of the built environment around the world. He states that by merging the two concepts of green buildings and preservation, we can ‘transform the legacy of the past into the promise of tomorrow.’

The built environment makes up the areas we live, work, and socialise, but in the UK alone buildings are responsible for 45% of total carbon emissions and 32% of all landfill waste comes from their construction and demolition[1]. Integration of sustainable practices such as the design, delivery and operation of buildings and infrastructure has become essential for conservation efforts; after all once we build it is then an existing structure, so how we preserve it becomes important for future generations.

The development of ‘green buildings’ is a well-known course of action to contribute to a more sustainable built environment. In recent years, we commonly identify these as having biophilic design and covered in foliage on the outside, whilst the inside focuses on increasing the efficiency of its energy, water, and materials. Elefante highlights in 2007 the ‘green building movement’ was emerging as a significant way to combat environmental damage, but he also directs attention to the simple fact:

‘We cannot build our way to sustainability; we must conserve our way to it.’
– Carl Elefante AIA, LEED AP (2007) in The Journal of National Trust for Historic Perseveration, Volume 21 – No 4.

Although these new buildings visually look ‘greener’, how sustainable are they? We must consider the carbon emitted in the construction of the building and, the eventual, dismantling process – from extracting raw materials and manufacturing components, to the toxic environmental effects because of demolition. The retention of embodied carbon in existing buildings presents a significant challenge to the sector and demonstrates how sustainability cannot be fully achieved if these practices are only applied to new buildings.

A significant portion of the UK and USA’s infrastructure is ageing – in the UK 23% of our domestic building stock pre-dates 1919 and we have 500,000 listed buildings in this country and 7,000 conservation areas[2]. Elefante notes in his article that 6% of existing building stock in the USA was constructed before 1920 and that a much larger building stock of modern-era buildings (dating from the 1950s-80s) need to become the larger focus, as these non-residential buildings equate to 36 million square feet in the USA.

The reality is that many reinforced concrete and masonry-clad structures will be nearing the end of their service life, and some prematurely, due to the way they have been constructed and reacted to their environment over the years.

Structural Corrosion

Retaining embodied carbon combined with the introduction of Environmental Social Governance (ESG), by the UK Government in all public procurement projects from 1 January 2021, presents the sector with very little choice but to opt for innovations that provide improved resilience methods that respect the environment, whilst giving the industry incentives to develop work, products and services that are aligned with the new policy. It is the adoption of sustainable build materials, for both restoration and new-build projects, alongside the implementation of retrofit systems that extend asset’s service life which will successfully contribute to the reduction of global greenhouse gas emissions.

C-Probe does this through, the innovation of LoCem®, an alkali activated cementitious material (AACM) – a more sustainable alternative to cement that produces up to 90% less CO2 emissions, compared to CEM 1, with a focus on smart controllable corrosion protection products. C-Probe has spent the last 20 years providing sustainable resilience to buildings via retrofitted systems that uses cathodic protection to prevent corrosion, which can be monitored and managed remotely by their open network system to provide service life tracking. This technology is transferrable to new build to provide controlled resilience from day one.

An example of LoCem®’s use was in it’s first commercial use, at the Commerce Trust Building in Kansas, USA which was built in 1906. At the time of the project, this structure was 107 years old and was facing corrosion damage to the internal steel-frame (which is how the majority of 19th Century buildings are built). It was agreed that Impressed Current Cathodic Protection (ICCP) was the best approach for protecting this building, whilst also providing a controllable solution for the long-term. The ICCP system was installed alongside LoCem® anode mortar, replacing the bed joints, which provided benefits through its electrical current carrying capabilities and low carbon credentials. This then being linked to an online network management system (AchillesICP and AiMS) where remote control and monitoring of the system can occur, created a successful and sustainable system for the protection of this building for it’s whole life.

Commerce Trust Building, Kansas

Commerce Trust Building, Kansas

Elefante makes an important point that society is “drunk on the new and now”, clouding our judgment in making legitimate sustainable decisions. To ensure that the ‘new and now’ is resilient, we need to be focusing on the use of innovations that can aid structural preservation efforts, leaving positive legacy for future generations in a cultural, secure, and environmental sense.

“As preservation teaches us all to better value the past…it also helps us to fully awaken to our responsibilities to the future…this is the unbreakable bond between preservation and sustainability.”
– Carl Elefante AIA, LEED AP (2007) in The Journal of National Trust for Historic Perseveration, Volume 21 – No 4.

To learn more about C-Probe’s anode mortars and sustainable resilience management systems, view their product page here:

[1] Martin Sexton, Sustainability, The Changing Built Environment,

[2] Grosvenor, Our response to ‘Planning for the Future’

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