Part L1B 2026 Notice:All replacement windows in England & Wales must achieve whole-window U-value ≤ 1.4 W/m²K with FENSA/Certass certification or Council LABC sign-off.
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Statutory Guides & Glazing Analyses

UK Window Replacement Guides & Building Regulations

Everything UK property owners need to know about Approved Document L1B energy ratings, FENSA self-certification, frame styles, and cost optimization.