Ours are about 10 years old and going strong, got summer and winter weight ones, each goes to the cleaners at the end of its season. I also put them on the washing line for a freshen up every now and then.
I have my first feather duvet. It goes crossways on the guest bed as an extra layer and looks qite nice in a toning colour arranged like that. I got it when I was 13 so nearly 40 years old. The duvets on our bed are duck down and I bought them in 1988. Every summer I put them over the washing lne for a mega air and have them professionsally cleaned when we decorate - same as the pillows.
All the others are synthetic ones and the singles go through the machine - the double has a service wash.
Thank you all for your replies. I'd just noticed a lack of loft with some duvets, so wondered how to plump them up. I'm lucky in having a balcony outside the main bedroom to hang out the duvets to air/collect spider webs/get shat on by birds.
I can't be doing with the synthetic ones as they're full of slippery stuff that makes you fall over if you step on it while changing the bedlinen.
Am researching wool-filled duvets (I should say doonas) that are very popular in Australia.
Ambridge - there is a company which offers a recovering service, they make made to measure sheets eg 4 ft and extra deep, they advertise in home & garden type magazines. I think they are based at a seaside town, I will try and think of the name.