Things like three piece suite, other furniture, curtains, carpets.
I've just realised that my living room curtains, that I think of as "new" are more than 15 years old 
The sofas must be nearly 25 yo (I know they're older than DS1, so they've been through the wars!)
I has disappointed to see my stair carpet has a bald patch, but it is 20yo 
I recently replaced a 30 yo dining table and chairs, which actually was still fine, but it was cheap when new, the first thing we bought for our first home and I decided to upgrade.
I do like to buy good quality in the hope it lasts, but are these timescales reasonable/normal?
Or do "most" people modernise more often?