Put simply, retrofitting is the installation of elements or technologies into existing buildings which weren’t there previously, for purposes including reducing the carbon emissions they produce.

Unquestionably. These include can include:

On the last of these themes, real estate advisors JLL have found green buildings achieve premiums of 20 per cent in capital value and average rent increases 11 per cent higher than those of less environmentally friendly structures.

In September 2023, the UK Government reneged on various environmental policy commitments and disbanded the Energy Efficiency Taskforce, the group of specialists which advised it on reducing energy demand by 15 per cent between 2021 and 2030. However, the government says it remains committed to the UK having net zero carbon emissions by 2050 (the Scottish administration has set its own target date of 2045).

According to the Westminster government, the built environment accounts for around 40 per cent of current UK carbon discharges.

Emissions from buildings are classed as either embodied or operational. Embodied emissions are those associated with the design and construction process – through the use of materials such as cement and steel, for example – and comprise about 11 per cent of the overall total. The operational sort are those associated with buildings’ day-to-day running – through features such as the energy consumption associated with heating, lighting or air conditioning systems – and account for around 28 per cent of all discharges.

Great strides have been made in cutting emissions associated with developing and constructing new buildings and infrastructure during recent years. But the UK Green Building Council (UKGBC) estimates that 80 per cent of the stock in use by 2050 have already been built and decarbonising the existing stock, much of which has been erected without minimised emissions in mind, will therefore be vital if we’re to get anywhere near meeting that net zero target.

The UKGBC says:

No, and this is a major cultural barrier to achieving what’s needed. The UK construction sector has traditionally adopted the alternative, carbon-intensive, approach of demolition, followed by new building. That tendency can be partly explained by the costs of refurbishment often having exceeded a construction’s value. Also, until March 2022, most new UK buildings were exempt from VAT, while the bulk of refurbishments and repairs attracted the tax at a rate of 20 per cent.

It’s also worth noting that long-standing shortages of people skilled in retrofitting buildings have been an obstacle to changing that “raze and rebuild” approach. Solving this problem has hardly been helped by developments such as the coronavirus pandemic and the ending of free movement of workers from the EU following Brexit.

Not yet. But the UK government’s direction of travel was clearly indicated by a landmark decision of Michael Gove, Secretary of State for Levelling Up, Housing and Communities, in July 2023. Mr Gove overturned a recommendation from planning inspectors, by refusing giant retailer Marks & Spencer permission to demolish and rebuild its flagship store on London’s Oxford Street. His reason was the carbon footprint such a project would generate.

It’s also expected that governments will tighten Building Regulations in the years ahead, following Future Buildings Standard consultations. This would take further current requirements enshrined in documents such as PAS 2030:2019 and PAS 2035, which set out standards for energy efficiency, the latter dealing specifically with retrofits. Already, all commercial properties will be required to have Energy Performance Certificate ratings of C or higher by 2028 and B or higher by 2030, for example, with premises failing to achieve these levels effectively becoming unlettable.

The industry should continue to follow the pathway identified by the UKGBC, which recommends:

The answer will depend on the outcomes of whole life carbon assessments (see “What practical steps should I take?” below) but, generally, a comprehensive retrofit project may be preferred in order to:

You’d expect me to say this, but one way to ensure you gain to the greatest extent is by engaging the services of a qualified professional, such as a specialist construction industry carbon management consultant. They’ll guide and advise you through what is often a complex, highly technical process.

The UKGBC says six key actions should drive non-residential retrofit:

The key maxim here is “get to know your building”. Without a good understanding of factors such as the construction, its components and how it’s operated, you won’t be able to plan and implement the most suitable retrofit strategy.

You therefore need firstly to measure and monitor existing energy consumption. Familiarise yourself with how the building and its occupants consume energy, identifying patterns and potential areas of concern. Bear in mind that lighting, heating and ventilation typically account for 60 to 75 per cent of a commercial building’s primary energy use.

Concurrently, collect information on the construction and its components, including its fabric, heating systems and unregulated energy uses. This should include details of components’ expected remaining lifespans.

All this data will show you if the building is being operated with maximum efficiency. Where that isn’t happening, occupants should be made aware of how they can help rectify this.

You’ll now have a baseline of operation and consumption for your building, which you can compare against energy efficiency standards, to highlight shortfalls on best practice. This will also help identify the potential challenges and opportunities you need to consider when developing your retrofit programme.

To help you understand the gap between existing performance and what can be achieved through retrofitting, the Low Energy Transformation Initiative, a network of 1,000 built environment professionals working to put the UK on a path to net zero, has published realistic target figures for energy use intensity (the amount consumed per square metre of a building).

When you have all this information it’s time to do some modelling. You should undertake whole life carbon assessments, to help determine the options which will have the greatest impact on improving energy efficiencies and reducing associated carbon emissions.

You should never replace something without modelling it. Retaining an existing component with a long remaining lifespan could be less carbon intensive than replacing it. Full information is the key to a successful retrofit.

You may have heard this one before, but the key is “know your building”. That means monitoring and reviewing its post-retrofit performance, to gauge whether your targets are being achieved. If not, investigate to identify what corrective actions you need to take. You may have to tweak building systems, to ensure they’re working at peak efficiency, or provide training and information to occupants, to ensure they know how the building should be operated, for example.

Yes. Perhaps the world’s highest-profile instance of a building being transformed in recent years through retrofitting is New York’s Empire State Building. There, measures taken included changing the more than 6,500 windows – reusing over 95 per cent of the original frames and glassware – and installing lifts that generate electricity, rather than heat, when braking. The result is energy consumption has been reduced by over 40 per cent and annual savings achieved of more than $4.4m (over £3.6m) in bills.