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  • Writer's pictureCliff L'Aimable _Chartered Surveyor & Building Engineer

Updated Building Regulations FLOS

Updated: Nov 27, 2022

29.4.2022_A brief blog overview by Cliff L'Aimable at Building Control Surveyors Ltd Approved Inspectors

My company and team offers private Building Regulation Approvals, technical design checking and site inspections of all building projects. Tel 01992 710 763 EmaIL

Approved Document Part F (Ventilation)

Approved Document Part L (Conservation of fuel and power)

Approved Document Part 0 (Overheating)

Approved Document Part S (Infrastructure for charging electric vehicles)

are the documents published by HM Government which you should consult for guidance - they are free to download from the government's website ...

Photo above : Blogger Cliff L'Aimable Technical author - In the Den at our offices in Warlies Park House, Essex.

Its a bumper package of updates that I am checking out this April 2022 from my den !! at Warlies Park House (Building Control) - so let's get started and quickly overview them !!

The updated parts of the Building Regulations (Approved Documents) which come into effect on 15 June 2022 are pictured above.

FLOS - So to be clear this has nothing to do with the dynamic world of oral hygiene !!

Its all to do with how we construct or modify buildings, to achieve even better energy conservation, which are comfortable and healthy to inhabit, now built with conveniences ready for a future where combustion engined cars become museum pieces or re-cycled into toasters !! - Oh - I better get serious now... So....

Photo: The autonomous electric car developed by ZOOX (looks like a toaster !) Credit : ZOOX

Getting back to FLOS , These updates introduce new stepping stones whilst raising the bar in the existing energy efficiency standards, and guides us clearly towards the government’s new Future Homes Standard (due to be introduced in 2025) which ambitiously leads us to the future proofing of new buildings which incorporate low-carbon heating systems and high fabric efficiency standards.

The Building Regulations for England include amendments to Approved Documents – Part F (ventilation), and Part L (Conservation of fuel and power), as well as the release of a new approved document Part O (Overheating) and approved document Part S (Infrastructure for the charging of electric vehicles). Collectively known as FLOS.

Targets set by government

New and existing dwellings account for around 20% of all carbon emissions in the United Kingdom. In order to reach the United Kingdom's ambitious goal of achieving "net-zero" greenhouse gas emissions by 2050, the government has committed to establishing the "Future Homes Standard" in 2025. This is expected to result in a 75-80 percent reduction in carbon emissions compared to current national criteria for energy efficiency. They intend to accomplish this by implementing extremely high fabric efficiency standards and low-carbon heating systems. Beyond 2025, additional growth is anticipated to serve as an additional stepping stone towards the 2050 goal of carbon neutrality.

Consultation Outcome

A transitional step towards the "greater" objective was established , the government conducted a consultation on the Future Homes Standard at the end of 2019.

The consultation examined ideas for enhancing energy efficiency standards in Approved Document L1 for dwellings.

Aware of the delicate relationship between energy efficiency, airtightness, and healthy ventilation needs, Part L updates was complemented by updated and associative proposals for Part F (Ventilation) and its associated Approved Documents. The consultation lasted until February 2020 and covered buildings throughout England. 

In addition to new methods to minimise overheating in dwellings constructed to the new requirements, proposals for revisions to Part L2 governing non-residential buildings were also considered.

What is Net Zero?

By 2050, the UK government intends to have net-zero emissions of greenhouse gases - a very ambitious target ! - but thats for another rant - oops sorry blog....

So with this iteration to Part L, updates contained throughout its pages are very much in line with the predictions leaked between "parties of interest"over the preceding months prior to publication. This should although not detract from the reality that the revisions mark a fairly positive step to furthering our journey towards the governments net zero strategy.

For those still with me - I need to explain what this talk of ‘Net Zero’ is actually about.

I can confirm that it has nothing to do with UK fishing rights lost after Brexit !!!!

Net Zero = Well the balance between the amount of greenhouse gas produced and the amount removed from the atmosphere is known as net zero. When the amount we add is exactly equal to the amount subtracted, we have reached net zero.

FLOS the new Approved Documents

The government released two new approved documents (AD) at the end of 2021: AD Part F, which addresses ventilation , and AD Part L addressing the conservation of fuel and power.

Volumes 1 dealt with homes, and Volumes 2 covered buildings other than residences. Both L and F were published as two volumes.

Volumes 1 dealt with homes, and Volumes 2 covered buildings other than residences. Both L and F were published as two volumes.

AD L and F are complemented by a brand-new Approved Document O that addressed home overheating. New dwellings constructed to the new criteria should now emit 31% less CO2 than those constructed under the old Approved Documents.

A new technical guide introducing a requirement to cover the installation and provision of charge points for electrical vehicle in a brand new AD Part S of the Building Regulations .

Provisions during the transition period

The revised building regulations t he revised FLOS guidelines will take effect on June 15, 2022. Any applicants accepted before this date must begin work by June 2023 due to the 12-month transition period. In other words, starting after that date, means the revised standards will be used to evaluate any new building regulations applications.

To hasten implementation and stop developers from just  filing applications for large developments early in order to lock in the earlier energy efficiency standards, transition rules for F, L, and O have been strengthened.

Individual houses or apartment (flats) developments must begin construction before June 2023; not to entire developments covered by an application.

Transitional requirements will continue to apply to notices or submissions under section S (No. 2 Regulations).

Changes to the FLOS Building Regulations in Brief

Part F: Modifications to Approved Document

• streamlining the process for calculating a home's ventilation rate and system design needs.

• updating the Approved Document's presentation of ventilation systems to meet industry standards for design and the most recent research on indoor air quality.

• adding instructions to the main body of the approved document to lessen the entry of outside air pollution.

• streamlining the guidance's organisation and information.

Updates to a Document Approved Part L

Two documents have been created from Approved Document L 2021:

- Volume 1 for dwellings 

- Volume 2  for buildings other than dwellings 

By using primary energy as a performance parameter, this modifies the building's minimum energy performance target. Along with the target fabric efficiency rate, target CO2 emissions, and minimal requirements for the building fabric and system efficiencies, this is now of elevated importance.

Along with the target fabric efficiency rate, target CO2 emissions, and minimal requirements for the building fabric and system efficiencies, this is now of elevated importance. The newly approved document additionally:

• Upgrades the requirements for a "notional habitation" that serves as the foundation for minimal SAP performance. A solar PV array and wastewater heat recovery are anticipated to be included.

• Enhances the minimum fabric efficiency standards for new and replacement thermal elements, windows, and doors, as well as the minimum insulation standards applicable to building additions and alterations.

• Enhances the fixed building services' minimal efficiencies

• Prepares new homes for the future by requiring a 30% carbon reduction for all new homes and a 27% reduction for other structures, as well as stricter CO2 emissions objectives.

;The introduction of a new metric for all buildings—the maximum permitted primary energy rate

; the introduction of a new Part L compliance (BREL) report highlighting the us of photographic proofs to show compliance with energy-efficiency requirements in Part L and as-built performance

;The introduction of a new metric for all buildings—the maximum permitted primary energy rate

; the introduction of a new Part L compliance (BREL) report highlighting the use of photographic proofs to show compliance with energy-efficiency requirements in Part L and as-built performance.

The following features are introduced:


• For wet space heating systems a maximum flow temperature of 55°C

• On-site audit of building details and thermal elements is required during construction and at completion

• New dwellings mandatory user guides

• Assistance through basic education of building occupants on how to operate low-carbon homes.

Overheating: New Approved Document O

A newly approved document that aims to eliminate the need for high energy-consuming air conditioning systems in homes that might otherwise be prone to overheating goes hand in hand with the higher standards for energy efficiency.

The primary considerations now presented being:

• Limitations on unwelcome solar gain. Depending on the façade's direction and whether or not the building can be cross-ventilated, maximum glass areas to be determined.

• Establishing minimal opening areas and requiring methods to evacuate surplus heat from indoor spaces

• Two optional ways to prove compliance. Using a set of predetermined design guidelines or dynamic thermal modelling, as described in the CIBSE guidance document TM59.

• We can anticipate a larger usage of strategies like shutters, blinds, overhangs, awnings, and reflecting glass on South-facing elevations under the latter approach.

• Insofar as it is practical, the new guidance emphasises the value of choosing passive cooling and ventilation methods over mechanical ones.

• Cross-references between AD F and external noise and pollution

• The security of ground floor windows should be taken into account if they must be opened as part of the overheating mitigation plan. using cross references Part Q requirements

• Establishes stricter ('high risk location') guidelines specifically for Greater London.

• Similar to ventilation, there are regulations requiring home user manuals to inform owners and occupants of how to utilise the building efficiently.

Infrastructure for the charging of electric vehicles - New Approved Document 0

The guidance in Approved Document S

applies to the following types of building work.

a. New residential buildings.

b. New non-residential buildings.

c. Buildings undergoing material change of use.

d. Residential buildings undergoing major renovation*.

e. Non-residential buildings undergoing major renovation*.

f. Mixed-use buildings undergoing relevant building work.

With occasional exceptions, buildings undergoing building work applicable (as mentioned above) will need to install a 7kW untethered EV charger or install cable routes that can supply power at a minimum. Around 30 miles of range can be obtained with 7kW per hour of charging.

*= Defined as renovating a car park on the property, altering its electrical system, or changing the electrical system of a facility that houses a car park.

The regulations, however, set a maximum cost cap of £3,600 for all work associated with installed points; if the cost is set to be higher, developers simply need to install the cable routes. This prevents the installation of EV chargers from becoming unaffordable. As a result, greener EVs will become a new design factor when building homes and sites in the UK, allaying the anxieties of UK auto buyers.

Further training sources

My blog overview is not exhaustive is browse through !!! – As always though I recommend you book your training updates with bodies like the Chartered Association of Building Engineers, so you can obtain a CPD certificate of attendance and so you can delve even deeper into this new stuff, without the distractions of me talking about old cars being converted into toaster !


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