Regulating Carbon Zero

Paul Bainbridge, Technical Director

Paul’s Greenprints   

At the time of writing this blog, we’re awaiting the release of the new Part L (2025) Building Regulations for the Future Homes Standard, which means that by the time you’ve finished reading this sentence, everything we’d intended to write could already be incorrect or out of date.

(Half) joking aside, however, this is exactly why we write our blogs here at The FES Group – so that we can give you the most up-to-date and easily accessible information possible for the good of the work we’re all doing in the construction industry.

With house builders and new homes professionals always looking to our team for guidance, it’s always important that we get the information not only spot-on, but handed to you in a way that makes everything as simple and clear to understand as possible. This blog about the incoming Part L (2025) is no different.

The Future Homes Standard consultation was initially released on the 13th of December 2023, together with a consultation into the new Home Energy Model (HEM), which is the eventual proposed replacement for the Standard Assessment Procedure (SAP). Yes, of course you can expect a blog on this one from the team at The FES Group in the very near future.

The 12-week consultations meant that resulting agreements and outcomes were due early March for us to report on, but here we are, writing this in June. And the reason for writing it at all? Simple – to cover some basics for you. Firstly, we’ll look at how everything will be enforced and transitioned from this point onwards under the new Part L 2025. Secondly, we’ll look at why the Part L 2025 is coming into force in the first place (spoiler alert, it’s because we’re moving towards the readiness of Zero Carbon homes of the future).

The key proposed question raised within the most recent consultation for the Future Homes Standard centred on the enforcement of/transition to the new regulations under Part L (2025). In summary, what was up for discussion was whether enforcement and transition periods should be 6 months or 12 months in duration. Under the most recent/previous regulations, a 6-month enforcement period was the norm when the Part L (2021) came into existence. This gave house builders working on the Part L (2013) regulations 6 months of grace before having to make any reasonable changes to their plans and builds for new site registrations. The following transitional period then gave them another 12 months after that to start ‘uplifting’ their designs for future plots on existing sites and any new sites registered with Building Control after the enforcement period. 6 months has always been a fair expectation before any new regulations become enforceable for home builders, but then came talks of the introduction of the new Home Energy Model (HEM), which was initially proposed to replace SAP. Had this replacement indeed come into fruition in being launched alongside the new Part L 2025, it was felt that enforcement may take (and possibly deserve) more time to come together – possibly even a full 12 months.

Of course, in this game, consultation doesn’t necessarily mean conversion, and the Government have since announced that rather than directly replace SAP with HEM, the excitingly titled SAP 10.3 will be used in the interim to make sure that HEM is fully ready at a later date. That’s likely to be announced in the Approved Document we now expect in December 2025, with – according to a recent BBC News segment – any updates on this expected to come directly from Ed Miliband (Secretary of State for Energy Security and Net Zero) during the Autumn.

With all of this in mind, it’s looking like the new industry-expected 12-month enforcement period could remain (presently) at 6 months. Still, it’s fun having these kinds of small and insignificant details change on such a regular basis, isn’t it?

So essentially, in waiting for the new Part L (2025), the team at The FES Group are looking out (on behalf of you as our clients, of course) for any changes in the enforcement period for new sites moving between regulations, and exploring how long the transition period will be for existing sites being built on a plot-by-plot basis.

Previously, when house builders have designed sites, submitted planning permission, and danced their merry dances with Building Control, the site has then been built to the current and appropriate regulations at that time. It didn’t matter how long it then took the house builder to build any or all of the planned plots; 2 years, 5 years, donkey’s years… no matter. This was always the case until the last lot of regulations (Part L 2021), when there was a change! From that point onwards, everything had to be considered and constructed on a plot-by-plot basis. So, if that change came in whilst you were only 20 houses into a 50-house site, those remaining 30 plots would need to be uplifted (within a timeframe, of course) to meet the incoming regulations. And so, when this new edition (Part L 2025) finally comes in, house builders can continue to register sites under the old regulations until the enforcement kicks in, at which point they’ll then need to a) uplift any remaining plots on existing sites, and b) start the whole process of new build sites from scratch conforming to the new regulations.

It’s essentially a three-phrase timeline. First, we have the production of the new Approved Document. Then, there’s the period of time before enforcement of that document kicks in to apply to new sites. And finally, there’s the transition period where everything needs to be on track to move to the uplift for existing/ongoing sites to comply with the new (Zero Carbon Ready) regulations.

To illustrate this point as an example, if the Part L (2025) document shows that the enforcement period and transition period are both 12 months, then house builders registering active sites today may not have houses completed under the new regulations until 2027. With the new HEM calculations eventually coming to replace SAP, there would be lots more to think about, design, and plan for, so we’d ordinarily be fairly certain that this 12-month transition would indeed replace the existing 6 months. However, as already mentioned, with SAP 10.3 coming in as an interim assessment measure to bridge SAP and HEM, we’re leaning heavily towards thinking that the enforcement period will remain at 6 months. We’re not ones to say we’re usually right about these things, but we are, in fact, usually right about these things. Terms and Conditions Apply.

This same theory applies if that document is released today and you register your site tomorrow (or even next week), because once you hit the point of registration, we can safely assume that all your planning, design, and costing in line with previous regulations has been stringently done to this point. Costing is of course always a huge factor when new regulations are produced, because the uplift to comply will be significant. In general, an uplift could be in the region of £10k per plot, so this is especially key for large developers with multiple sites and many plots.  At The FES Group, we’ll always play our part to make sure you’re informed around all of these factors, because you absolutely need to know how any change in regulations is going to impact you financially, above anything else.

And so, now we know how much time we’ve got to transition, uplift, and of course comply with our future home-building – and we can expect that this will carry cost and design implications as standard – but what exactly will be reflected in these changes to Part L (2025) in the first place, and why will they be so important?

Essentially, the Government are looking to get house builders to become ‘Zero Carbon Ready’ in their constructions; in other words, reducing operational carbon emissions to the lowest possible level, and offsetting any remaining emissions through the use of renewable energy instead of traditional fossil fuels to heat, light, and ventilate the home. It’s proposed in the new regulations that all energy performance requirements will be based on notional buildings fitted with an efficient Air Source Heat Pump (or a 4th generation heat network that uses an Air Source Heat Pump). This change ensures the lack of need to retrofit any future homes in order to reduce carbon emissions as the electricity grid decarbonises moving forward.

As a result, there will be no practical way to allow the installation of fossil fuel boilers in future builds, so gas boilers as we know them, hybrid heat pumps, and even hydrogen-ready boilers… will simply not meet the new standards and therefore won’t be compliant.

The Future Homes Standard is also unlikely to allow the installation of biofuel systems, including those ever-so-chic woodburners we’ve all dreamed of installing to keep up with the Joneses. This ‘lack of a woodburner’ scenario certainly takes the shine off buyers wanting to rent out their new builds on AirBnB as a “cosy eco-friendly nest” and subsequently charge the earth (ironically) for a one-night stay, but there we have it. Planet, good people – not profit.

In the case of communal buildings such as flats and apartments (in case you were wondering about those), new low-carbon communal and district heat networks will likely be the preferred ways of providing heating and hot water to residents – just for info.

A misconception around all of this, of course, is that ‘getting rid of gas in favour of electric’ will help in the work towards Zero Carbon. It won’t. What works towards Zero Carbon is the use of an air source heat pump, which just so happens to be powered by electric. Electric on its own is not the answer, and it’s important to know this distinction.

There’s no doubt that even this one change in building regulations will help us work towards a healthier and happier planet. But will it help us work towards healthier and happier home builders in the process?

Let’s wait and see, shall we?