Improving the energy efficiency of buildings

In 1973 & 1979, uncertainty over oil supply and spiralling oil costs led nations to think carefully about the production, and sensible use of energy (Gosse, 1986).

Today, climate change is driving a fundamental and wholesale reconsideration about the production and sensible use of energy, together with a move to de-carbonise energy production, and to reduce the energy demand for transport, buildings and industry.

The main character in Jonathon Porritt’s (2013) fictitious account of life in the year 2050, looks back to 2010 and recalls that –

“more than 40% of total energy consumption was used by buildings – a lot of which was completely wasted because the buildings were so inefficient. It was, in effect, like taking piles of cash (the paper notes they used back then) out of the bank every day and setting fire to them”.

Although this extract is from a work of future fiction, the quote neatly sums up the current situation, and the challenge we face to reduce energy use in buildings. Other contributors are raising public awareness, including Extinction Rebellion (2019) and the Swedish student, Greta Thunberg (Thunberg, 2019). However, raising awareness is one thing, taking action is another, and action is required if energy reduction targets are to be met, or exceeded. The urgency to reduce carbon emissions in the UK is palpable.

Climate emergencies have been declared by a large number Local Authorities across the UK, see below.

And on the 1st May 2019 the House of Commons passed a motion –

“That this House declares an environment and climate emergency following the finding of the Inter-governmental Panel on Climate Change that to avoid a more than 1.5°C rise in global warming, global emissions would need to fall by around 45 per cent from 2010 levels by 2030, reaching net zero by around 2050…..” (UK Parliament, 2019).

For the construction industry there are two approaches to net zero carbon, firstly during the construction phase, and secondly through the operational life of the building. There is a third approach – whole life net zero carbon – but more work is required to define the scope and requirements (UKGBC, 2019). The Definition of net zero carbon during the construction phase is –

“When the amount of carbon emissions associated with a building’s product and construction stages up to practical completion is zero or negative, through the use of offsets or the net export of on-site renewable energy.” (UKGBC, 2019)

And for operational energy –

“When the amount of carbon emissions associated with the building’s operational energy on an annual basis is zero or negative. A net zero carbon building is highly energy efficient and powered from on-site and/or off-site renewable energy sources, with any remaining carbon balance offset.” (UKGBC, 2019)

Refurbishment can be a significant contributor towards achieving net carbon buildings, as it has the potential to maximise the use of existing buildings, reduce energy consumption optimise their use and reduce the amount of new construction that is required.