"Amber Ormerod" wrote in message
...
HI,
When the books say east-west line for the spine of the greenhouse I am
presuming they mean to use magnetic north/south? Does it matter that much
if
I am out a fraction?

We are having a concrete base laid next week and I am having a hole for
water to drain and some holes for wires/pipes to go in later. Is there
anything else I should consider when having the base set in? (we are on a
slope and will have a drain by the door put in when I get the path sorted
out, the back end is down hill atm or would be)

thanks
amber

The difference between the 'Norths' is relatively unimportant.
Use a local map and use the North indicated. Just check for trees and
potential shade.
"Down hill"? With a glass greenhouse it is best to buid up the foundations
so that all is level. Have you a means of getting the rainwater inside?
Have the structure well anchored onto the foundations or it could fly.
Hope all goes well. Brian.