Nick wibbled:

I have wooden window frames in my house which contain smallish sealed
double glazed units.

The units total dimensions are appox 49cm x 46cm x 1.7cm.

The units are held in place by four wooden strips.

All in all pretty cheap and nasty.

Is it possible to get replacement units and fit them myself. If so how
should I specify dimensions and where do I order them from.

I did phone one supplier but he said they need to be measured and fitted
by a professional which seem a bit strange.

If you mean the double glazing panels (units) then any high street glazier
should be able to make or have them made for you. Varies between 70-100+
quid / m2 from plain old annealed glass to annealed K glass to toughened K
glass to argon filling.

It would be best to pop the beading off and exactly measure your existing
units then quote that size to the glazier.

If you want a whole DG frame, www.windowsanddoors.co.uk look interesting -
but I haven't used them - the local glazier pretty much matches their price
and produces some top notch uPVC frames.

BTW what's wrong with your current windows?

Cheers

Tim