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.