In message , stuart noble
writes
Nightjar "cpb"@ insertmysurnamehere wrote:
Arthur51 wrote:
I've read a few posts from the past here and people have talked of
14mm upto 22m thick options.

What are the advantages/disadavatages of thin against thicker
double glazed units?

The units I want are for my timber front door frame..sidelights and
top light
to be fitted into 45mm x 20mm deep rebates.
Up to a 20mm air gap, the larger the spacing between the panes of
glass, the better the insulation. Above that, air can circulate
within the window, which makes larger gaps less effective. Smaller
thicknesses are usually easier to retrofit.
Colin Bignell

"Stepped" units can be useful for shallow rebates. IIRC they don't look
too clever from the inside though.

ISTR some years back a Matthew Marks describing how he routed out some
French Windows to fit DG sealed units in them.
--
Chris French