Episode 16: L is for Life Cycle Assessment

Choosing the right materials for your building isn't always easy as all materials have pros and cons.

When looking at the best materials to use from a sustainability perspective, a life cycle assessment can be really helpful. The assessment looks at the processes involved for a material across its entire life cycle - from raw material extraction all the way to end of life.

This assessment helps to bring perspective to the overall environmental impact of the material rather than focusing on one or two elements - for example, some materials that may seem less sustainable in the earlier stages (such as extraction or manufacturing) may actually balance this out in the of end of life phase by being able to be recycled.

Episode 15: I is for Integrated Design

Integrated design is where the different specialisms involved in a construction project (such as architects, main contractors, project managers and quantity surveyors) are brought together to collaborate from very early on in the process - ideally as early as RIBA Stage 1.

Bringing these specialisms together should enable better decisions about the project to be made as all of the experts can provide relevant information for you to consider.

This is particularly important for sustainable construction as it allows the specialisms to collaborate and find holistic solutions, which can include things like how you can get the most energy efficient building or reduce waste.

Episode 14: F is for Fossil Fuels

Fossil fuels are found in the Earth's crust and are made over millions of years from decomposing plants and animals. Examples of fossil fuels include coal, oil and natural gas.

When these are burned, carbon dioxide, which is a greenhouse gas, is released into the air forming a barrier around the Earth that traps heat in .

Fossil fuels are also a finite resource as it can take more than 650 million years for the decomposing plants and animals to transition into usable fossil fuels - which is why they fall into the category of 'non-renewable energy'.

The Intergovernmental Panel on Climate Change has warned that if we continue burning these fuels at the same rate as we currently are today, we will hit a catastrophic climate tipping point at around 2030.

Episode 13: E is for Environmental Product Declarations

Also known as an EPD, this is a document that quantifiably demonstrates the environmental impact associated with a product's lifetime. They are based on the data obtained through carrying out a life cycle assessment and are verified by a third party.

An EPD supports decision making and carbon reduction initiatives by enabling users to compare the environmental impacts of different materials and products. They are generally valid for five years, after which they need to be updated.

Historically the costs associated with developing EPD have been a barrier to more widespread adoption by manufacturers and although the number of available EPD is steadily increasing, they are still relatively small in number.

Episode 12: E is for Environmental Net Gain

Environmental net gain is an approach to development that leaves both biodiversity and the environment in a measurably better state than it was prior to development.

The concept was launched in 2018 as part of the Government’s 25 Year Plan to Improve the Environment but there are no timescales for making it mandatory.

This approach builds upon the concept of Biodiversity Net Gain but also considers how sites can contribute wider environmental benefits like storing flood water to reduce the risk of flooding.

Episode 11: E is for Energy Synergy™

Energy Synergy™ is Willmott Dixon's in-house system for measuring and improving a building's energy performance. It has two main uses.

The first use is around helping to design the most efficient buildings. The system provides energy modelling that covers all building energy uses – this means that if you want to make changes to a building’s design, we can work out what the positive or negative outcomes will be in relation to energy.

Using this modelling gives our team information that will help you to make the most sustainable decisions and get the most sustainable building possible for your budget. It also helps us to set targets that we will then measure performance against further down the line.

The second use is when a building is operational. There can be many reasons why it doesn't perform as expected in terms of its energy usage, for example, changes in design and specification through the project, commissioning setups that are not optimal, lack of understanding on how best to operate and control equipment, and changes in the way the building is used or equipped when operational.

A system like Energy Synergy™ allows us to measure the actual energy performance of a building so we can compare the results to the target data. This detailed comparison helps us to pinpoint why the building isn't performing as it should be so these areas can be corrected. This will potentially save energy costs and carbon emissions, as well as reducing the impact on the environment.

Find out more about Energy Synergy™

Episode 10: E is for Embodied Carbon

Embodied carbon is the total greenhouse gas emissions (often simplified to 'carbon') generated to produce a building.

It excludes operational emissions but includes those related to the extraction of all raw materials, manufacture and processing of all products or systems required in a building, transportation of those to site, assembly on site, and any maintenance or replacement activities required during the lifetime of those products or systems.

It also includes end of life processes, such as deconstruction and eventual disposal or reuse/recycling.

Episode 9: D is for DEC and EPC

A Display Energy Certificate, also known as a DEC, is a building certificate for non-domestic buildings.

A DEC rating is based on the actual energy usage and carbon emissions of the building when it's in operation. It gives a full picture of the in-use energy efficiency of the whole building as it covers both regulated and unregulated sources of energy.

An Energy Performance Certificate, also known as an EPC, can apply to both domestic and non-domestic buildings.

Unlike a DEC, an EPC rating is a theoretical calculation made at design or build stage. It doesn't take into account unregulated energy sources (which includes things like IT equipment, lab equipment, lifts and catering facilities), meaning the rating doesn't give a true view of how energy efficient a building is.

Episode 8: D is for Decarbonisation

D is for Decarbonisation This has become a commonly used word when talking about how to stop further climate change. It refers to the measures a project, organisation or industry needs to take to reduce their carbon footprint - mainly its emission of greenhouse gases.

In terms of construction, this relates to both the creation of new buildings and the retrofitting of existing ones.

In both cases the first step is to make buildings as efficient as possible by reducing the amount of energy they require for heating, cooling and lighting. The second step is to ensure the remaining energy needs are met by renewable energy sources.

Decarbonisation, particularly in retrofit, is incredibly important to allow us to meet the UK's 2050 net zero target as most of the buildings that will be around in 2050 already exist.

Find out more about Willmott Dixon's Decarbonisation service

Episode 7: C is for Circular Economy

A traditional, linear economy has a wasteful process of "take, make, use, dispose of".

A circular economy maximises usage to its fullest by designing out waste, designing in adaptability and keeping products and materials in use for as long as possible.

In construction this could be how concrete is reused. When an old building is demolished, often the concrete can be crushed and reused in a new building.

Equally, it might be worth thinking about how you can apply this to entire buildings. There are alternatives to knocking down a building and building a new one, such as medium and major refurbishments.

Episode 6: C is for Carbon Offsetting

Carbon offsetting is the practice of compensating for the carbon emissions you produce by purchasing measurable, verified credits.

One carbon credit is equal to one tonne of carbon dioxide being reduced, avoided or removed from the atmosphere from certified projects. Examples of projects could include tree planting or building a wind farm.

A credible offsetting scheme will provide certified credits that can only be used once, and they will result in carbon reduction that is additional to what would have happened anyway without the project.

The fact that carbon credits can only be used once is important to note. When it comes to a building’s operational carbon (which is the carbon produced when you’re running a building) the carbon produced must be offset every year.

Episode 5: C is for Carbon Neutral

A great way to think of carbon neutral is that it's a key milestone that you should hit on the way to achieving the end-goal, which is net-zero carbon.

The principle behind being carbon neutral is that any carbon emissions produced are being balanced out by funding an equivalent amount of carbon savings elsewhere in the world.

A carbon-neutral company, product or building may not necessarily be low carbon, but a sustainable organisation will try to reduce its emissions before offsetting and will only use high-quality, verified credits.

Episode 4: C for Carbon Footprint

A building has its own carbon footprint. This is the amount of greenhouse gases that are produced throughout the entire lifecycle of the building. This includes the gases produced in the manufacture and supply of the materials, the actual construction of the building, the running of the building, any retrofitting or upgrades and the demolition of the building.

For every organisation, their carbon dioxide emissions are categorised into one of three scopes. For the following examples, we have focused on how an organisation would classify the emissions relating to the creation and running of their building.

Scope 3 emissions primarily relate to an organisation's supply chain. When a contractor is hired to build a new building, any emissions produced would fall into the organisation's scope 3 emissions as they are the customer.

Scope 2 emissions come into effect once the building is operational, it relates to the electricity that is used.

Scope 1 emissions also apply to an operational building. This includes things like any gas that is used.

Episode 3: B for BREEAM

BREEAM stands for 'Building Research Establishment Environmental Assessment Method'. In short, it's a standard that outlines the best practice in sustainable building design, construction and operation. You may hear buildings being called BREEAM Excellent, Good, etc. This is how the building measures against best-practice benchmarks. BREEAM can be used for new buildings, fit-out projects and when buildings are in-use. If you want to aim for a BREEAM certification, it's important to raise this early in the process as the assessment spans across the lifecycle of the project - from concept to design to construction to hand-over.

Episode 2: B for Biodiversity Net Gain

Biodiversity is all the different kinds of life you'll find in one area—including all of the animals, plants and other organisms that make up our natural world. These organisms work together in ecosystems, like an intricate web, to balance and support our natural areas. They provide vital functions such as flood prevention and improving air quality, and having access to nature can also help to improve people’s physical and mental wellbeing.

Biodiversity net gain (sometimes referred to as BNG) is the term used to describe the process of increasing the overall biodiversity value of a development site. Biodiversity net gain sits within the Environment Act. From November 2023, the Act requires all development schemes in England to deliver 10% biodiversity net gain, which must also be maintained for a period of at least 30 years.

When it comes to construction projects, it's important that biodiversity is taken into account right at the beginning of the project to maximise the benefits gained within the site. Adding it on later down the line can be much more costly.

Episode 1: A for Air, water and ground source heat pumps

All of these pumps use naturally occurring heat to provide a more efficient and renewable means of heating a building and getting hot water. All of them use electricity to generate heat in a super-efficient way, typically creating two-three units of useful heat for each unit of electricity, and completely avoiding the use of fossil fuels like gas. The real difference between them is where they get the heat from - as the names suggest, the air source heat pump gets it from the air, the ground source heat pump gets it from water loops in the ground, and the water source heat pump gets it from a nearby lake or river.

Ground and water source heat pumps are quite site-specific in how they can be applied to buildings, and they tend to be the most efficient- air source heat pumps can be used on all building types, are quite cost-effective, and are typically a bit less efficient.

How are we Simplifying Sustainability in our own business?

It's through our Now or Never Sustainable Development Strategy, which is split into three themes: Brilliant Buildings, Building Lives and Better Planet.

Find out more about our approach here.