Warranty Position Regulatory Position and Guidance Exemptions Does B4 still apply?
Green indicates we consider our position best practice and not in dispute Grey items cover the December 2018 Amendments, Approved Documents and MHCLG's own FAQs and advice notes Green indicates that the item IS exempt from Regulation 7(2), in accordance with Regulation 7(3) Green indicates that B4 still applies, and refers to relevant parts
Yellow indicates our position has the potential to be subjective   Red indicates that the item is NOT exempt. Refer to Regulation 7(3) Red shows that B4 no longer applies


Warranty Position

Explanation/Notes: Window screen frames are exempt.

Unless there is the potential for B4(1) to be contravened, e.g. if the window frames were manufactured from a combustible material (upvc, timber etc) and stacked or installed in a continuous row. In which case an assessment* would be required.

Is the position indisputable? Yes

December 2018 Amendment

Reference: 7(2)(iii)

Reference titles: any windows and doors in the wall.

Approved Document

Reference: 10.15(d)

Reference title(s): Regulation 7(2) and requirement B4: Additional considerations

Reference: Appendix A

Reference title(s): Key terms *External wall

MHCLG FAQS / Advice Notes

Reference: None

Reference title(s): None


Is the item exempt from Regulation 7(2), in accordance with Regulation 7(3)?: Yes

Reference: 7(3)(j)

Statement: window frames and glass.

If exempt, are there any restrictions on the use of the system, component or material given in the guidance in ADB vol 2?

Window spandrel panels and infill panels must comply with Regulation 10.15(d). Combustible thermal break materials should be limited in size to the minimum required to restrict the thermal bridging. 10.15(e).

Does B4 still apply?

YesReference: B4-(1)

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Disclaimer: The information in this document is believed to be correct in light of information currently available and at the time of publication but is not guaranteed. Neither LABC Warranty nor its agents can accept responsibility in respect of the contents or any events arising from the use of the information contained within this site. The guidance provided does not replace the reader’s professional judgement and any construction project should comply with the relevant Building Regulations or applicable technical standards. For the most up to date LABC Warranty technical guidance please refer to your Risk Management Surveyor and the latest version of the LABC Warranty Technical Manual.