How do you signal you are not available at home without letting your day turn into back-to-back meetings?

I work remotely from a fairly small apartment in a busy city and I have a weird problem: even when my calendar looks free, I am not actually available.

At the office it was obvious when someone was busy: headphones on or in a meeting room. At home, green status seems to mean “sure, hop on a quick call.” Those “quick” calls stack up and my focused work disappears.

I try to do async first: write things up, send a message, ask for questions in the thread. Still, a few teammates are very meeting-first and will ping “got 5 minutes?” several times a day. If I say no too often I worry I come across as unhelpful, but if I say yes I end up doing my real work late at night.

What has actually worked for you to communicate availability without being rude?

Specific things I am considering:

– Blocking focus time every day (but it feels like my whole calendar becomes blocked)

– Setting fixed office hours for ad hoc calls

– Changing my status to something like “heads down” and letting pings sit

– A rule like “propose an agenda in the message first”

If you have scripts you use, I would love to hear them. Also curious how you handle this with people in different time zones who default to synchronous help.