Search Results for: Glazing Components

The Construction Product Reform White Paper sets the future tone for the construction regulatory framework, the core of the reform is the principle of “safe products, used safely”. Moving away from a system that has in many ways helped facilitating trade toward one centred on product safety, accountability, and trust across the supply chain. Rather than representing another regulatory hurdle, the reform should be viewed as a necessary evolution following systemic failures highlighted by the Grenfell Tower Inquiry.

UKCA and CE marking are reaffirmed as declarations of performance against designated standards, not assurances of safety. This is not to say that two are not linked but we must move a focus to an understanding of how a product performs not just on its own but part of a system. Under the new regime, safety must be demonstrated through accurate, transparent, and verifiable product information, including clear limitations on use and evidence‑based performance claims.

A central focus of the White Paper is the overhaul of product information transparency. Consultation responses and inquiry findings exposed widespread issues with misleading marketing, fragmented data, selective disclosure of test results, and inconsistent oversight of voluntary schemes. These weaknesses have made it difficult for specifiers and installers to compare products reliably or confirm suitability. The reform introduces explicit duties around product information accuracy, traceability, and accessibility, creating a more level playing field by rewarding businesses that invest in proper testing, honest declarations, and clear installation guidance.

Where designated or harmonised standards do not exist, the introduction of the General Safety Requirement (GSR) provides a mechanism for products to be placed on the market but also how they can specify correctly and safely. Whilst the consultation for GSR has just launched, there are concerns on how this will work where manufacturers make components of wider systems, or where “white labelling” of products is carried out. That said it is likely it will require that manufacturers and suppliers demonstrate that products are safe for their intended and foreseeable use, supported by proportionate and documented evidence. This shifts reliance away from CE marking alone and places greater emphasis on clear product limitations, traceability, and substantiated claims. For the glass and glazing sector, whilst it begins at manufacture, the GSR reinforces that safety must be actively demonstrated, documented, and communicated throughout the supply chain.

The paper also highlights the need for a system-based approach that is supported by competent workforce, who understand the importance of compliance to design, particularly for safety‑critical applications such as fire‑resistant glazing. Installer knowledge, correct specification, and system level assurance are positioned as integral to delivering the safe outcomes.

Regulatory intent is further underlined by the Office for Product Safety and Standards (OPSS) report on heat‑soaking. While focused on a specific process, it highlights that documentation errors are no longer minor administrative issues. Inaccurate declarations of performance can directly result in misspecification and unsafe installations. Factory production control, initial type testing, production testing, and evidence‑supported claims must all be accurate, current, and auditable.

Importantly, responsibility extends across the entire glass and glazing supply chain. Substituting products, altering fixings, or deviating from approved systems without evidence now carries clear regulatory risk. Informal or undocumented changes are no longer defensible, the person that makes a change carries design responsibility.

Call to Action for GGF Member Companies

GGF Members should act now. Audit all product information, declarations of performance, and marketing claims for accuracy and alignment with test evidence. Ensure product limitations and conditions of use are clearly communicated and digitally accessible. Review competence in your business, prioritising gaps for safety‑critical work. Construction Product Reform demands not only compliance, but a cultural shift toward transparency, integrity, and evidence‑led decision‑making. Organisations that respond early will not only meet regulatory expectations but set the benchmark for trust and professionalism in the sector.

The Welsh Government has introduced the new Home Energy Model for u-value calculations for new build windows and doors – making the shift to triple-glazed units more likely.

Updates to Welsh Approved Document L and F were published on 7^th April. These follow the shift announced in the publication of the Future Homes Standard for England (24/3/26) to the new Home Energy Model.

This effectively introduces a move away from the Standard Model and SAP calculation, introducing a requirement to evidence actual rather than ‘theoretical’ performance for each individual window.

“The Home Energy Model introduces the requirement to assess each window to its actual size and configuration to arrive at an area weighted average”, explained Kevin Jones, Head of technical, Glass and Glazing Federation.

“That includes all the items that sit within the opening, for example transoms, mullions, dummy sashes, astragal and Georgian bars, add-on cills, head vents and other components.

“These weren’t visible under the Standard Model but are visible under the Home Energy Model.

“While the Welsh Home Energy Model will be based on the same calculation as that across the border in England, there is a significant difference in that the limiting u-value – in shorthand, the lowest acceptable level of thermal performance – is going to be 1.4 w/m²K, compared to 1.6w/m²K in England.

“Depending on the design of the window and the building fabric as a whole, that could make it more likely that developers will have to move to triple-glazed options to meet regulations.”

The changes come as governments in Cardiff and Westminster attempt to close a gap in performance between theoretical building product performance – and what they deliver in real-life applications. 

The changes will come into force on all new schemes started after 4^th March 2027 unless the work has been registered for an initial notice or relevant notification provision before 3^rd March 2027 and work starts before 3rd March 2028 in which case the old regulations will apply.

For any works where initial notice or relevant notification provision is not registered before 4^th March 2027 and work does not start prior to 4^th March 2028 the new regulations will need to be followed.

“While there are transitional arrangements in place, the changes to the Welsh Approved Document L and in particular, that limiting u-value of 1.4 w/m²K are going to drive housebuilders to focus very closely on the weighted average as a whole.

“It would be our expectation that that will push a lot of developers to specify triple-glazed windows, which clearly has big ramifications for cost and future window design.”

GGF members will be able to take a look in more detail and have the opportunity to ask questions at the summer launch of the new GGF Wales regional event, details of which will be released soon.

For support, contact the GGF Technical team at technical@ggf.org.uk  or visit www.ggf.org.uk

Welsh Approved Document L can be found here

Ends

For further press information please contact:

John Warren

07971829772

john@lascomarketing.co.uk

New regulation forcing manufacturers and housebuilders to evidence the u-value for the exact configuration of each individual window supplied into new build, could drive a shift to triple-glazing.

The Future Homes Standard was published on Tuesday [24/3/26].

While notional u-values were held as outlined in Approved Document L at 1.2w/m²K for new build windows, the revision introduces a move away from the standard model of calculation to a specific assessment of each individual window supplied – something which may force developers to move to triple-glazed specifications to achieve compliance.

“The age of the ‘standard calculation window’ is effectively over for new build,”
said Kevin Jones, Head of Technical at the Glass and Glazing Federation (GGF).


“Under the Home Energy Model, every window has to be calculated to its actual size and configuration o arrive at an area weighted average. That includes all the items that sit within the opening. That’s a huge change in mindset and methodology for both housebuilders and their window and door suppliers.”

It comes as the Government attempts to close a gap in performance between theoretical building product performance – and what they deliver in real-life applications. 

At the heart of the change is the move away from SAP to the new Home Energy Model (HEM) for new homes.

This effectively means modelling each specific window configuration. That creates a challenge because most of windows supplied in a real-world context are smaller than the ‘standard’ window configuration (1230×1480 open/fixed) used to model u-values.

The smaller the glazed area, the harder it is to achieve a u-value of 1.2 W/m²K, especially where windows feature transoms, mullions, dummy sashes, astragal and Georgian bars, add-on cills, head vents and other components.

“Government has been very clear that the model of the home needs to reflect what is actually built,”
explained Kevin.


“That means everything in the window opening that affects thermal performance has to be taken into account. Up to now, most calculations have been based on relatively simple, clean configurations. Under the new regime, the real-world complexity of modern window designs is brought into the calculation.

“On a big, simple window with a high glass-to-frame ratio, you can often achieve compliance with a well‑specified double glazed unit. But when you start adding dummy sashes, transoms, Georgian bars and so on – particularly in smaller apertures – you’re making life much more challenging in thermal terms.”

Structural elements of the window or door which can negatively impact thermal performance, for example steel reinforcements and load bearing structural couplers, do not need to be included in the u-value calculation.

The shift also puts software and systems houses in an immediate race against time to create and integrate u-value configurators into their manufacturing processes before the end of the transition period.

The Approved Document states that changes ‘take effect on 24 March 2027 for use in England for building work that is not in connection with higher-risk building work’ and ‘24 September 2027 for use in England for building work that is in connection with higher-risk building work’.

The full transitional arrangements are noted in Circular Letter 01/2026 which can be found with the link below.

The Future Homes and Buildings Standards: Building Circular 01/2026 – GOV.UK

The Letter states that for non-high risk buildings (HRB) the new regulations will not apply to work where a building notice, an initial notice, or an application for building control with full plans approval has been given before 24^th March 2027, and the work starts before 24^th March 2028.

These changes to the 2010 and 2024 Regulations come into force on 24 September 2027 for HRB work (including a stage of HRB work) or work to an existing HRB and separate commencement and transitional arrangements apply in these circumstances. The Regulations do not apply to HRB work or work to an existing HRB work where a valid building control approval application has been submitted to the regulator before 24 September 2027, and the application has not been rejected before, on or after that date.  Where transitional protection begins because of the submission of an application for building control approval for a stage of HRB work then the protection will continue to apply to subsequent stages of HRB work, provided that the original application has not been rejected or lapsed.

For now, at least, for domestic replacement, the current regime, including the use of standard sizes and styles for U‑value declarations, essentially remains unchanged, however Kevin warned that an extension into window and door replacement, was the logical next step.  “Everything we’re seeing points to this being a staging post, not the final destination,” he said.


Kevin concluded: “The Future Homes Standard doesn’t just tweak the numbers – it changes the rules of the game for new build window and door specification

“Those who move early, understand the detail and invest in the right tools and relationships will be in a strong position.

“Those who wait until 2027 and hope for the best are likely to face difficult conversations, disrupted projects and squeezed margins. Now is the time for the trade to get on the front foot.”

For support, contact the GGF Technical team at technical@ggf.org.uk  or visit www.ggf.org.uk

Approved Document L can be found here.

For further press information please contact:

John Warren

07971829772

john@lascomarketing.co.uk