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Forums Forums LOFT CONVERSION FORUM UK Replacing Velux Windows in Loft Conversion

  • Replacing Velux Windows in Loft Conversion

    Posted by Andy Clarke on January 2, 2026 at 12:30 pm

    Can anyone explain whether we need to worry about building regs at all when getting existing roof windows (one velux, one unknown) replaced in our existing loft conversion? It’s simply a matter of them needing replaced/updated. May be minor change to size of the non-velux one as the veluxes come in standard sizes. With normal sash windows, we used a fensa registered installer, but can’t find any info on whether any such scheme exists for roof windows or if we need building control approval as an alternative (but surely not?!).

    Thank you!

    DANNY O'DONAGHUE replied 3 months, 3 weeks ago 7 Members · 8 Replies
  • 8 Replies
  • Olivia Johnson

    Member
    January 2, 2026 at 12:31 pm

    Interesting question, I assumed that once the extension was signed off it becomes much like the rest of the house. In the sense of, if I was to replace a door or window on the lower floors I wouldn’t need building control/regs. I’d just change them if they had become faulty over the years. I don’t know the proper answer to your question. Just my own thoughts, it was an interesting question as I hadn’t really thought about that scenario.

  • Mia Thomas

    Member
    January 2, 2026 at 12:31 pm

    Check your council planning webpage. They will say what needs to be notified.

  • Benjamin Lee

    Member
    January 2, 2026 at 12:31 pm

    My instinct is to say no, replacement shouldn’t require anything further but best to confirm

  • Charlie Jones

    Member
    January 2, 2026 at 12:32 pm

    Simple replace like for like is not usually a planning /building regs problem – get Velux themselves to install so then guaranteed !

  • Michael Clarke

    Member
    January 2, 2026 at 12:34 pm

    No, but make sure they are Fensa registered installers. Good read ->

    Do I need Planning Permission? (and when you don’t) 2023

  • DANNY O'DONAGHUE

    Member
    January 2, 2026 at 12:35 pm

    We replace velux in our roof and due to them being a different size we needed building regs. The new one was smaller. So probably worth checking if they aren’t like for like?

  • Andy Clarke

    Member
    January 2, 2026 at 12:35 pm

    Do you mean you had to ensure the installation complied with building regs or you actually had to have the council out to sign off? Thank you!

  • DANNY O'DONAGHUE

    Member
    January 2, 2026 at 12:36 pm

    we had to get sign off

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