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8 Minute Read • Part L/Section 6

Wales confirms details and dates of new Part L

Part L/Section 6
Part L/Section 6

Wales confirms details and dates of new Part L


Wales confirms details and dates of new Part L

Following months of speculation, we have now received the first confirmed details for how the new look Approved Document Part L will work in Wales.

It’s after the Welsh Government released comments following a public consultation into changing L1A – that’s the section which sets energy targets for newly built homes.

Further announcements to cover work on existing buildings, overheating, and timeframes for transitional arrangements, are all expected to be confirmed this summer, with all documents expected to be finalised around October.

Builders in England will have to wait a few more months for confirmation, but we’re expecting the two countries to take a very similar path.

So, what has been confirmed for definite?

Make a note in your diaries… the go-live date has shifted slightly. Earlier documents suggested the new AD L would be released at the end of this year, but it has been pushed back to the Spring. This may be connected with rumours suggesting the English go-live date (originally June 2022) is being brought forward to the Spring.

For compliance with SAP, we are moving from one mandatory target to four!

The Target Emission Rate is staying, but is going to be 37% more strict than the current TER. This is the biggest change to SAP since it first became mandatory, and is going to push most developers towards using heat pumps or PV panels to guarantee compliance.

The days of complying with a gas boiler and a bit of extra insulation are most definitely numbered.

The TER is being joined by the Target Primary Energy Rate. This is calculated in the same way as the TER, but looks at energy use instead of emissions.

Thirdly, all newly built houses will need to achieve either an A or B rated EPC. This new target is called ‘Householder Affordability’ and has been introduced to tackle fuel poverty by encouraging designs which reduce fuel bills. Looking at last year’s data, 1 in 8 of all newly built homes in Wales don’t meet this target.

Finally, limiting U-Values are becoming mandatory (under the current AD L, it is only best practice). All buildings assessed under the new AD L must comply with all four targets to achieve sign-off.

Aside from the new targets, there are several new additions to AD L which could cause further complications…

Collecting photographic evidence will be required to confirm insulation has been positioned correctly, that the correct ventilation and heating systems have been installed, and that an air test has been completed. Every new house, flat and bungalow will need its own archive of photographs during construction.

Air testing is also becoming mandatory. Every new dwelling will need to be tested. The new AD L allows for two methods; site managers can choose between the conventional door-fan test, or the new-style pulse test. The maximum allowed air test result is being reduced to 8.0.

Home Energy Guides will be required for all new homes to give occupants a non-technical instruction manual for using the buildings in an efficient way. The Guide may have to include copies of the construction photos, and signed copies of the compliant SAP reports. (The details are still being ironed out).

Meanwhile, two elements of the current AD L are being removed:

One of these is the overheating check, which uses the SAP model to flag up dwellings considered to be high risk. It’s being replaced with a brand new Approved Document, set to be launched on the same date (April 2022).

Regulation 25A, also known as the High Efficiency Alternative Systems report, is being simplified. Developers will still need to look at the viability of various low carbon and renewable systems for their site but will no longer have to give notice to the local authority (unless requested). The logic here seems to be that more homes will need renewable technology to comply with SAP, so there is less of a need to prove that renewables have been considered.

We’re expecting further announcements from both the Welsh and UK governments in the summer, and will release further articles as more details of the new regulations emerge.

If you’d like to know how your current specification is expected to fare against the new targets, speak to the Energist team about our SAP10 review.

You may also be interested in...


New Building Regulations in Wales


Delayed Scottish building regs are now live


New energy performance targets in Wales


Transitional Arrangements (Wales)


GLA Energy and Cooling Hierarchy: 2022 Changes



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