My bedroom door, when left open, provides an even bigger break in the fire resistant wall it's installed in.
However I don't understand anyone fitting non fire rated downlight nowadays, when even the most expensive ones are a few pounds. I wouldn't fit the open can tuppeny happeny tack sold by DIY stores. You're right about the speakers and what about ceiling extractor fans, you can get intumescent collars for them
OP mentioned a large dwelling house; Approved document B defines such as a residential accommodation occupied.... b) by not more than 6 people, living together as a single household. Not suggesting he should rip out existing luminaires, just as a discussion point for the original installation.
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