In article , david@abacus-
nurseries.co.uk says...

Hello Martin.
Thank you for replying. I have now found a company called
'Steeltechsheds' they say their greenhouses are built to last a lifetime
and are able to withstand extreme weather conditions. The frame is made
of Steel Hollow section. If you could take a look at their website and
tell me what you think.

Having looked at that site, I wouldn't touch them.
The frame may last a life time what ever that means.
The plastic sheeting may last up to around 10 years but 7 would be more
realistic.It may well discolour with sunlight, and tends to get brittle.
David
Abacus Nurseries.
I can see no ventilation, and you should ideally have 1/8th of the roof
area as vents

I agree. I don't see those poorly supported polycarbonate panels
standing up to coastal weather , either.

Why buy steel (which rusts) when all the other manufacturers use
aluminium, which doesn't.

No explanation of the "lifetime" guarantee, either.. how long has the
company been making GH's?

Janet