What is a sustainable building?

Everyone uses the term, but what is truly expected of a “sustainable building” in 2024? William Scott looks at key qualities required.

A sustainable building is often considered to be one that has been designed and constructed with a focus on environmental responsibility and resource efficiency throughout its entire lifecycle. This means from design to demolition the focus is on minimising the building’s impact on human health and the environment through the structure and mechanical and electrical services of the building.

The question is does this definition encapsulate the true extent of what it is to be a sustainable building? Arguably this is a rather narrow definition, as it focuses on the structure of the building and the physical aspects, whereas real sustainability incorporates so much more.

Beyond the physical

Take the UN Sustainable Development Goals as a broader understanding of what it is to be sustainable, so many of which relate to the built environment. For example, goals 3 (good health and wellbeing), 5 (gender equality), 6 (clean water and sanitation), 7 (affordable and clean energy), 8 (decent work and economic growth), 9 (industry, innovation and infrastructure), 11 (sustainable cities and communities), 12 (responsible consumption and production) and 13 (climate action).

This definition of sustainability is not just about infrastructure, but about communities and the use of the resources available to us and the space we inhabit. A key aspect to true sustainability therefore must incorporate the use and management of the space we occupy.

This is, however, not the full picture, as a sustainable building should be fit for long-term occupation, taking into account future climate risks (heat stress, flood risks, extreme weather) and the needs of the occupiers (flexible working, cycling facilities, promoting health and wellbeing).

The concept of sustainability and longevity is not new, as the Brundtland Report published as far back as 1987 defined sustainable development as development that meets the needs of the present without compromising the ability of future generations to meet their own needs. Flexibility and a holistic approach of the impact of human action is therefore also a fundamental part of being sustainable.

A high hurdle

We are evidently asking a lot from a building if it is to be sustainable. Not only must the building be designed and constructed in such a manner as to minimise its carbon impact, but it must also support and enhance the society that inhabits it to further their environmental and social objectives, creating a healthy and safe environment in which to live and work, with minimal operational carbon, while enabling the economic development of the businesses within it – all while creating a flexible space that will support generations to come, whose occupational requirements and demands are unknown.

As this incorporates considerations from site selection to the choice of materials and method of construction, along with the optimisation of the consumption of utilities, that means that to be a sustainable building it needs to be sustainable from the start, thereby excluding all pre-existing buildings.

Given the vast majority of the building stock in both the commercial and residential markets in the UK is old and therefore would not fall within the above definition of a sustainable buildings, does this mean that most of us cannot occupy a sustainable building?

What about retrofitting?

One obvious argument is that retrofitting old buildings must be the most sustainable solution to the current property market in the UK. According to the UK Green Building Council, embodied carbon makes up 20% of the UK built environment’s emissions.

This embodied carbon includes the upfront, in-use and end-of-life embodied carbon, ie the carbon emissions associated with each of those stages of the building’s lifecycle. As such, retrofitting old buildings using low carbon materials and modern construction methods must surely enable a building to be considered sustainable.

It is not, however, simply about embodied carbon, as for a building to be sustainable we need to take into account the operational carbon, ie the carbon emissions arising from the occupation and operation of the building (an organisation’s scope 1 and 2 emissions). The focus with regard to carbon emissions in the built environment has primarily been on operational emissions, as they amount to about 80% of total carbon emissions.

Reducing your operational carbon is therefore a key priority for any organisation, and will form a core role in any net-zero action plan. Any building will therefore play a starring role in this strategy. Anyone struggling with this might consider availing themselves of a net-zero readiness assessment. The commonly adopted near-term net-zero goal date of 2030 is after all only 2,000 days away.

Assessment and accreditation

A lot of what is mentioned above can of course be assessed and certified, and building accreditation is therefore a good measure of part of what it means to be a sustainable building. The number of different types of accreditation has exploded over recent years, but the focus of these is on embodied and operational carbon and essential aspects of a building, such as access to natural light, clean air and water.

It is very well documented that environments with good air and water quality and lots of natural light help to improve the productivity and health and wellbeing of the occupiers. As such, surely the use of a building itself is a key (but perhaps underrated) consideration in whether a building is truly sustainable.

After all, you can have a total passive green building, built in accordance with the latest low carbon construction methods, but if it is not used, then it surely cannot be considered sustainable within the wider meaning.

If the manner in which a building is managed and occupied is truly a factor in whether a building is actually sustainable, then the lifecycle of that building needs to be considered in detail and the occupier or owner must consider what action at each stage can be taken to improve its sustainability.

The real estate lifecycle

There are four key stages to the lifecycle of a building site: identification, acquisition, occupation and disposal. At each of these stages, the manner in which the owner/occupier manages the building can have a positive impact on its sustainability. For example, during the site identification stage, buildings can either be selected according to their accreditation, or detailed surveys of the mechanical and electrical services, structure and space can be carried out to assess the viability of a retrofit rather than rebuild.

During the acquisition stage, parties can seek to impose environmental obligations to support the future use of the property in a low carbon manner. Here arises the opportunity in leasehold transactions for the landlord and tenant to adopt a more collaborative approach to their relationship and agree on key ESG objectives, drafting the relevant agreements to enable the parties to work together to use their building as a tool for achieving their common objectives.

This would go beyond simply sharing data, but adopting a code of practice and embracing ideas from the circular rather than the linear economy, thereby focusing more on sustainability than pure profitability. A good example of this is obligations around repair, energy use, alterations and ultimately dilapidations.

A holistic ESG approach

A building’s sustainability is therefore not only about the physical structure and M&E, but about how the building is managed and occupied, given the nature of the majority of our building stock. An ESG-focused strategy is crucial. It is down to us to take the lead and realise the benefit that can be obtained from our buildings to achieve our individual ESG objectives.

This article first appeared in EG