Renovate roof rafters and purlin heads

That the rafter and purlin heads are rotten

The rafters and purlin heads are rotten

... I consider that to be a rumor. I only see a worn-looking white paint without any indication of damage underneath. Normal paint aging after about thirty years, no drama.

Yes, the roofer who was here said that the rafter is completely rotten, especially at the upper middle purlin

A roofer is not a carpenter. Bakers also sell sandwiches, even with ham, but that does not make them butchers. Still, believe him if you have money to spare. If you have the entire roof redone, you will save hardly more than fifteen percent by reusing the current roof tiles compared to getting them all new. For nothing other than a weathered paint job.

If it was just about replacing the rafter, the whole roof doesn’t have to be redone.

What should I do now, what would you do?

If it was only about replacing the rafter, the whole roof doesn't have to be redone.

What should I do now, what would you do?

Find yourself another expert who explicitly confirms that the thing is rotten and will soon fall on your head.