Don’t rebuild, retrofit to meet net zero goals - Sarah Peterson

Countless spaces across the UK’s city centres have become derelict due to the post-pandemic shift to working from home or the rise of new builds. But as the number of derelict spaces continues to grow, it begs the question-who is responsible and how can we better utilise them to meet Scotland’s ambitious net zero targets?

We often don’t think of them in this way, but in reality, our houses, offices and shopping malls all have large carbon footprints. The choices of how we construct our buildings, use them, and where they are located all matter, as today the construction and operation of buildings globally account for the largest portion (39%) of global energy-related carbon emissions.

A building’s carbon footprint is twofold: the initial emissions produced to make a building, known as “embodied carbon”, is the sum of carbon that is needed to manufacture and transport materials to construction sites plus the impact of the construction processes. Day-to-day energy use, such as lighting and heating, is classified as “operational carbon emissions”. Throughout a building’s lifespan, it is reported that embodied emissions rack up one quarter of the building’s total carbon impact.

Numerous pledges were made at COP26 with a pact to lower global temperature to 1.5 degrees, but with less focus on carbon offsetting schemes there’s been an obvious gap left behind which can help reduce the energy intensity of our built environments and in turn be more efficient. The Scottish Government has outlined that all buildings must be carbon Net Zero by 2050 and recently opened a £300m funding pot to incentivise low carbon heating systems, but we still have an uphill struggle with only 1% of buildings today are considered Net Zero carbon.

Sarah Peterson, Director at multi-disciplinary engineering consultancy, Harley Haddow

To meet these carbon-cutting targets, the Scottish Government’s strategy needs to focus on retrofits, rather than on the construction of new, low-carbon “green” buildings. Nowadays, developers tend to favour knocking derelict buildings down, which isn’t necessarily better for the environment. Retrofitting, in simple terms modifying an existing building, eliminates the high energy costs of demolition and the negative environmental impact of taking materials to landfills and limits the embodied carbon related to new construction.

If the Scottish Government were to cement incentives around retrofit and impediments to demolition in legislation, we could move quickly towards meeting our carbon targets. Before a building is demolished, there should be a more rigorous analysis of the environmental consequences which is a core service we offer at Harley Haddow. Disincentives, such as taxes on carbon production of new materials can also be persuasive tools. On the flip side, many materials removed during renovation are wasted. There must also be stricter guidance that require buildings to be taken apart more carefully during retrofits to allow materials to be recovered and reused.

At Harley Haddow, our designs have always embedded sustainable, low energy and low carbon building principles and we bring this extensive experience to allow us to deliver Net Zero buildings and master plans, creating holistic solutions that prioritise carbon targets.

Sarah Peterson, Director at multi-disciplinary engineering consultancy, Harley Haddow