The road to Net Zero

In 2018, heating and powering homes accounted for 22% of all greenhouse gas emissions in the UK; as of December 2021, heating and powering buildings made up 40% of the UK’s total energy use. Keeping this in mind, as the country races to meet the deadline of zero net carbon in 2050, it’s clear that the target cannot be met without radical changes in how we heat and power our buildings.

The June 2022 Building Regulations update in England demands that all new homes produce 31% less carbon emissions than what was previously acceptable. The changes required were outlined under Part L of Building Regulations, which regulates the efficiency of buildings.

This is a steppingstone towards even higher standards. In 2025, yet more stringent requirements are due to come into effect with the Future Homes Standard (FHS), which will demand all new builds going forward produce 75-80% less carbon emissions.

So, what is the FHS, and how does it set the UK up for success in meeting the 2050 zero net target?

The FHS aims to improve the overall energy efficiency of new homes. It looks to achieve this by introducing stricter building codes, with several amendments to Part F (Ventilation) and Part L (Fuel and Energy Economy) of all building codes, as well as tackling overheating in new dwellings.

With low-carbon heating and “world-leading levels of energy efficiency”, dwellings built under the FHS will have a smaller carbon footprint than any building before them. As the electricity grid decarbonises, the Government says, even that small footprint will be reduced to the point the homes will reach zero net carbon – which will be mandatory for all new builds from 2030 onwards.

“The Government has dual ambitions of achieving net zero emissions by 2050 and continuing our progress towards achieving 300,000 homes a year by the mid- 2020s,” the Government said in a statement.

“These objectives are not mutually exclusive, and with good planning and smart design we can build the homes we need while protecting and enhancing the natural environment and adjusting to climate change.

“The introduction of the Future Homes Standard will ensure that an average home will produce at least 75% lower CO2 emissions than one built to current energy efficiency requirements. In the short term this represents a considerable improvement in the energy efficiency standards for new homes. Homes built under the Future Homes Standard will be ‘zero carbon ready’, which means that in the longer term, no further retrofit work for energy efficiency will be necessary to enable them to become zero-carbon homes as the electricity grid continues to decarbonise.”

A 75% reduction in carbon emissions in the span of a few years may seem overly ambitious. That said, it’s worth noting that not only did the proposal receive widespread support among building industry professionals – including designers, engineers, surveyors, manufacturers, builders, developers, and other figures in the supply chain – but that a sizeable number of these professionals found the FHS 75-80% target too low.

This shows two things: that this target can be achieved, and that the building industry is eager to meet and even surpass the requirements – building net zero homes, rather than just ‘zero carbon ready’ ones, by 2025 – ahead of the mandatory switch planned for 2030.

In keeping with this objective of delivering 100% net zero buildings by 2025, the Low Energy Transformation Initiative (LETI) has created a guidance from 2020 to 2030, with targets to meet on the way.

By the end of 2023, 60% of designed new buildings should be zero carbon; by the end of 2024, this figure should be up to 80%, to then reach 100% the following year – getting to 2023 with all built new buildings being already zero net carbon.

We have previously talked about the importance of following the Energy Hierarchy [link to article?] in order to reduce a new-build home’s carbon footprint all the way down to net zero, from reducing the energy needs through intelligent house design and insulating building materials to ensuring the needs remaining are met through clean and renewable energy.

This hierarchy informs any approach towards turning a ‘zero carbon ready’ home, as per FHS, into a fully net zero one which produces at least as much energy as it consumes.

There is however something else to consider: the building’s Whole Life-Cycle Carbon (WLC) emissions. WLC emissions are the carbon emissions that come not only from the use of a building over its entire life (operational carbon), but also from the materials, construction, and the eventual demolition and disposal of the building (embodied carbon). While there is a lot of focus on bringing operational carbon emissions down to zero, both must be considered for any dwelling to be truly net zero.

LETI’s guidance sets forward a hierarchy of primary actions to take to curb embodied carbon emissions, supporting a circular economy. These actions include:

Build less: if possible, consider retrofitting existing buildings instead of building new ones; consider using existing materials near the site; consider if all the materials proposed are necessary; keep in mind that simplifying the design can mean less embodied carbon emissions.

Build light: if possible, reduce the weight of the dead loads and avoid long spans.

Build wise: ensure longevity of materials used; consider adhering to standard building sizes or repeating modules; aim for a 100% utilisation rate; source materials locally if possible; design buildings to fit the site’s topography, limiting the need for on-site works.

Build low carbon: reduce the use of high embodied carbon materials; consider the use of natural and renewable materials; consider reducing embodied carbon through the use of Explore Design for Manufacture and Assembly (DfMA) solutions.

– Build for the future: consider future uses for the materials in your design; consider regular structural grid and future-proofed risers and central plant space; ensure any intervention leaves the material in the state to be dismounted for re-use and recycling.

Build collaboratively: cooperation from the entire design team, as well as the client, is needed for data-driven decision making since the early stage of the design.

Whether or not all LETI’s proposed deadlines are met, it is paramount for the building industry to move in this direction in order to reach the 2050 net zero target. What’s more, it’s clear that this is something that the industry is both able and willing to do.

When an organisation turns to us at Sustain Quality, they gain access to a team of professionals that are dedicated to providing services that help save on energy costs.

Sustainability consultants are incredibly knowledgeable in the steps that need to be taken to create net-zero buildings for organisations of all sizes.

Some of the assessments that may be used to best determine how you can meet net-zero energy include: