In article ,
says...

I thought that 12 by 8 would be a good size for a
greenhouse,
I saw this on the net
'Europa Manor Viscount 8x12 - Greenhouses Direct'
(http://tinyurl.com/azfzss6)

thinking about it, might be a good idea to go for
the safety glass

If you have space and a deep enough pocket, go for the biggest size you
can possibly afford; you will never regret it.. as Charlie said, most
people end up regretting they didn't get a bigger one. a 12 X 10 allows
room for staging both sides and one end, with elbow space down the
middle.

I would go for the safety glass, the rainwater system (use to fill an
adjacent butt for GH watering), louvres and *at least* two roof vents
with automatic openers.. Green colour coating would be nice but is a
lower spending priority than size IMO

You can always improvise temporary staging for a few years then add
some better stuff later, when your wallet has recovered.

Don't be tempted to site the GH on the earth held down with pegs, its
a false economy. With high winds/climate change it's worth digging a
channel, fill with concrete and set bolt holes in it. Then you can bolt
the GH to an absolutely rigid "true" angled base that will never let it
distort/ shift in high wind.

In case you might one future day want to install power to the GH, lay a
couple of feet of flexible plastic pipe under the base now, as a future
conduit for wiring.

Janet