A guide to retrofitting (and how it could help us reach net zero)

Posted on: 22 May, 2024

Retrofitting could be the answer to how the built environment addresses its role in the climate crisis whilst satisfying demand for new buildings and houses.

The UK has a problem with its housing and infrastructure.

Firstly, there’s the challenge of demand: The number of new homes being built in the country is set to fall to its lowest levels since the Second World War, as the construction industry struggles to maintain the pace with an ever-growing population. It’s not just homes that are needed, either – three-quarters of the infrastructure that will exist by 2050 has yet to be built.

Secondly, there’s the need to become more sustainable as we find ourselves in the middle of a climate emergency. Residential homes are responsible for almost 20% of all carbon emissions. The construction industry and the built environment as a whole is already one of the most pollutive industries in the world, and is responsible for around 40% of all greenhouse gas emissions by various estimates.

All of these issues are only compounded when the age of the UK’s housing is addressed. We have the oldest housing stock in Europe, with a significant number of homes dating back from before 1919. The modern buildings our sector produces have increasingly short lifespans, but the environmental impact of demolition and rebuilding puts the traditional building process at direct odds with any efforts to make construction sustainable.

Learn more: The concrete crisis: what’s being done to address RAAC risks?

That leaves us with a conundrum: What do we do about our ageing buildings and infrastructure?

The rejection of Marks and Spencer’s plans to demolish and rebuild their famous ‘Marble Arch’ store in Oxford Street, London perhaps exemplify the debate best. For many, the benefits (financially and environmentally) of tearing down and rebuilding structures from the ground up to modern standards outweigh the environmental impact of this process. For others, retrofitting and optimising existing buildings with energy-efficient technologies is the best way to deal with ageing buildings.

But what exactly is retrofitting, and could it play a part in helping us reach net zero?

What is retrofitting?

In construction, retrofitting is where new features and technologies are added to old and historical buildings. Buildings can be retrofitted for various reasons, such as to make them more energy efficient or improve their climate resilience.

Retrofitting makes homes more sustainable by improving their ability to retain heat and replacing their energy sources with renewable alternatives. Retrofit practices can range from small things like replacing halogen bulbs with LED energy-efficient light bulbs to more extensive deep retrofits, like adding new advanced heating systems. There are also seismic retrofits, which are designed to make buildings more resilient in the event of an earthquake.

How can buildings be retrofitted?

There are a wide range of retrofitting practices that can be applied to various elements of a building. Here are just a few that provide opportunities for greater energy efficiency:

  • Doors can be draught proofed to reduce air leakage
  • Windows can have double glazing replaced with triple glazing and draught proofing
  • Roofs can have optimised insulation and ventilation to avoid creating cold spots
  • Floors can be installed with insulation
  • Walls can have their surfaces cladded or fitted with cavity wall insulation
  • Lighting can be optimised through occupancy sensors and LED light bulbs
  • Air conditioning upgrades to replace fossil fuel systems, such as ground source heat pumps
  • Renewable energy sources such as solar panels and wind energy
  • Water conservation through things like shower heads and water fittings

What are the benefits of retrofitting a building?

There are several key benefits of retrofit interventions, including:

1. Improved energy efficiency (and is more cost-effective)

Historical buildings that aren’t built with modern sustainability knowledge will suffer from heat loss through uninsulated windows, doors, and a lack of proper wall and floor insulation. This will make heat systems work harder to maintain temperatures, leading to higher energy bills while also leaving the building more prone to issues like mould, condensation and damp.

Building retrofits can reduce heat loss through systems like air source heat pumps, optimising their energy performance. Efficient heating systems like this, along with things like improved loft insulation will mean reduced fuel bills and energy costs, as well as long-term energy savings for building owners.

2. Reduced urban sprawl

Being able to upgrade existing structures through building retrofits instead of seeking new developments gives businesses and homeowners more flexibility with locations. This can provide geographical advantages for organisations and also help combat urban sprawl and help preserve green and natural environments.

3. Better for the environment and sustainability

The question of sustainability was central to the debate around Marks and Spencer’s plans to demolish their Oxford Street store, as many felt the brand hadn’t properly considered retrofitting the building instead. The demolition and redevelopment process is an extremely pollutive one – campaigners estimated that the project would release 40,000 tonnes of CO2 into the atmosphere. In comparison, retrofitting is a far cleaner process that necessitates less energy consumption and has far less of a carbon footprint.

Learn more: To retrofit or not to retrofit: what’s the debate around the M&S Oxford Street demolition?

4. Increased building value

The UK energy crisis has placed high stock on efficient buildings and made this a significant consideration in the market. For both homeowners and businesses, building retrofits not only mean reduced energy bills, but in the long-term higher resale value, too.

5. Preserves cultural heritage and history

As with adaptive reuse, retrofitting initiatives can maintain the heritage behind famous and historical buildings, while allowing them to comply with modern sustainability and building efficiency standards.

Learn more: What is adaptive reuse (and how can it create a sustainable built environment)?

Retrofitting could help us reach net zero

Retrofitting has enormous potential and could play a central role in helping us achieve net zero. With so much demand on the built environment to develop more infrastructure and yet equal pressure to address its impact on the climate emergency, the UK’s ageing housing stock could (and should) be seen as an opportunity, not a thorn in our side. Retrofitting provides a more sustainable alternative to redevelopment, both in the short and long-term. And with our net zero carbon targets fast approaching, it’s an option we should all be considering.

Sustainability isn’t a passing trend – it’s here to stay and is constantly evolving. If you want to inspire and action change in your career, UCEM’s MSc Innovation in Sustainable Built Environments will give you the skills you need, both now and in the future.

Find out more:  MSc Innovation in Sustainable Built Environments – University College of Estate Management