Non-residential retrofitting: understanding the challenges
08/25/2023
Discussion and debate around sustainable development often focuses heavily on housing. But organisations across the public and voluntary sectors own and operate a huge variety of non-residential properties – from educational facilities to offices, warehouses and heritage buildings. Many are facing increasing pressure – from both outside and within their organisations – to ensure these buildings are constructed, maintained and used in a sustainable way.
Retrofitting offers a potential solution but also presents unique challenges
There is widespread recognition that demolishing existing properties and replacing them with more sustainable alternatives is rarely cost effective nor beneficial to the environment when the impact of building materials and construction processes is factored in.
Retrofitting existing buildings – for example by introducing new heating systems or insulation materials to improve energy performance – is viewed by many built environment experts as a better way to help meet the UK’s net-zero carbon targets.
Retrofitting sustainably can present challenges, however, with more constraints in terms of the materials and methods that can be used than when building new. This is especially true for charities, universities and other organisations in the public and voluntary sectors who own and operate listed and heritage buildings. The choice of materials and methods can have important implications for building resilience, building regulations and operations. Before embarking on any retrofitting project, there are a number of factors that organisations should consider.
1. Be clear on your objectives
Are the relevant stakeholders within your organisation aligned on what exactly needs to be achieved? Is there a holistic understanding of the best way to achieve your sustainability objectives while minimising the introduction of new risks?
For example, while retrofitting is one possible avenue to improve energy performance and minimise environmental impact, it might not always be the best option. Shutting down part of a building that has outlived its usefulness, or repurposing it so that it can be used by a greater number of people, might be another way of making that building more energy efficient, especially for buildings where making significant changes to the building fabric could present practical difficulties and introduce additional risks.
2. Prioritise your assets
It is important to have a strategic view of which buildings have a reasonable life expectancy and life demand before planning any retrofit. It should not simply be a case of prioritising buildings that are in the worst condition. What organisations should be looking to do is ensure the greatest return on investment in terms of both environmental and sustainability gains. Making changes to a building might improve its energy performance in the short-term, but if the building is in such a condition that it will only last a few more years, or if demand for the building is likely to fall off, then it would make more sense to invest resources elsewhere.
3. Have a robust programme of maintenance and repair
Regular repair and maintenance can help to improve energy performance and may prevent or postpone the requirement for substantial retrofitting. It also helps to ensure buildings are in the best possible condition when work does take place, which can minimise risks involved when installing new features such as heating systems, solar panels and insulation materials. In addition, if a building is poorly maintained, its life expectancy is reduced, thereby diminishing the benefit of any retrofitting measures undertaken.
4. Understand the risks and make compatible choices
A crucial consideration when retrofitting is the compatibility of the proposed materials and methods with the existing building fabric. Inappropriate choice of materials and methods can impact on building resilience in any number of ways. This is especially true of listed and heritage buildings.
If a building has stood for hundreds of years, it is important to ensure alterations do not undermine its inherent resilience. For example, insulating the roof void of a historic building to improve its thermal insulation performance could potentially undermine the building’s breathability (i.e. the way it is able to limit the build-up of harmful moisture). Combustibility is often another risk factor when retrofitting. Introducing a new combustible element to a building that has existing combustible elements can cause a ripple effect, significantly increasing the risk of damage due to fire.
Risks must be considered not just when the building is in use but also during the construction phase. Hot works, for example, can lead to significant or even total building losses. If you are renovating a heritage building that is a significant revenue earner, have you undertaken a cost/benefit or impact analysis in order to ensure the work sits within your risk appetite?
Clarity on risk and reward will help organisations prioritise sustainability goals
We realise that as organisations in the public and voluntary sectors, you are expected to play a leading role in delivering a more sustainable built environment. The latest report from the UN’s Intergovernmental Panel on Climate Change (IPCC) has brought into focus once again the urgent need for meaningful action to address the climate crisis. Retrofitting existing buildings is undoubtedly one of many ways to support sustainability goals, but as we have outlined in this article, it is not without its challenges. To succeed, organisations must have absolute clarity on their objectives and a clear understanding of how to achieve those objectives without introducing additional and unnecessary risks.
For more on this topic, download or listen to our whitepaper, Sustainability in a changing built environment: Rethinking sustainable construction and development.