[AndyRVTR]

I have the same as Gwiz, railway sleepers on each side, yes it creates a step but also adds about 10" to the height of the greenhouse.
I laid 5-6 small slabs down the middle and gravel beds on either side, it's also not as permanent as other types of bases 

[crh75]

I have a concrete ring for a base. It's a 6in wide and 10in deep.  The green house is screwed to it.

[wil4025]

As my garden slopes ive gone for moving some soil, adding 4 pegs in each corner and level each one off. Then Im going to add boards to create a bock section and then lay concrete solid base, level off with a bit of wood to get a smooth level surface. Im going to add a power supply and also add a drainage edge at the back.

Cost no more than £100 to lay concrete and about weekends worth of work. Currently digging at the moment.

[angelavdavis]

We couldn't financially go for sleepers, but went instead of large pressure treated fence posts and bolted the GH to these.  It still added some weight and so far the GH hasn't moved in the winds that come off the English Channel.  I just laid weed suppressing membrane down inside, tucked under the fence posts. 

[lassie]

I need to do a base too but still undecided about what to do.

I have a Halls metal base frame. What would be the best way to make this frame level, strong, and ensure that the wind does not get under it?

[sunshineband]

Like the sleeper idea.....and i have some.  How does this effect the doorway thou? Does it create a big step.

Also the base of my gh does it have fixing points or do you create them?

It does create a step. As for your geenhouse, I've never seen it so I couldn't say.

Just be sure to drill through under the door (rigth through the step) to avoid a large puddle forming on the inside when you are watering with gay abandon, or damping down the path in the hot summer weather we might get

I painted the top edge of the step white initially, to remind me toactually step over it, as I entered the green house rather faster than expected on day one!!!

[Amilo]

I used old sleepers, as cheap as I could find, wrapped the inside with builders DPB (plastic sheet) so the there was not contamination from the preservative and screwed the glass house frame to the sleepers. In west Wales the trees grow at 45 degrees with the wind but I have had no problems.

[RichardA]

I had some 3 inch thick  3 foot by 2 foot paving slabs that came off a drive we did away with. I laid them to form a path around the outside of the gh and built a wall of 4 inch thick concrete blocks one course so it was about 9 inches high aligned to just sit on inner edge of that paving slab rectangle and plug and screwed gh base to that. It means I step over a block at the doorway but I like the gh being taller and it all looks neat and tidy and can be approached on all sides for cleaning on a approx 20 inch wide path.
R