No instructions but if you're starting from scratch, rememeber that a
greenhouse is pretty symmetrical and typically built with 2 foot wide
windows. This helps a little when it comes to sorting out all the bits into
"first guess" locations.

When you get to adding the glass, you will either have S shaped plastic or
little metal clips. You will probably have similar clips for both side and
roof panels. The roof panels typically take clips that are "cut off" (ASCII
art below - show fixed font) unlike the side panels.


| Top glass lies here on top of...
+---+
Lower |
----+

Note the "not quite an S" used on the roof.

Upper glass lies OUTSIDE of...
|
V
| +---+
| | |
+---+ |
^
|
Inner glass

Note the "complete S" used on the sides

So, bottom glass panels go on first and glass nearest the gutters goes on
first on the roof. I also found that not tightening the bolts fully helps
since as you fit the glass you may need to flex the building to get it
completely square to get the glass to fit.

Finally a warning that despite the weight of glass, an aluminium greenhouse
can blow away - yes honestly! Mine moved about 6 inches from its concrete
base and I'm in a reasonably sheltered garden. Bolt yours down and get the
bolt holes drilled and aligned as almost the first thing you do. Adding
these after construction is a expletive deleted!

Good luck!
Paul DS.