with a small collection of miniatures, perhaps a lean-to gh would be a better option...connecting to the house would stabilize the structure, plus make it more of a joy to you personally as well....I have had both, and this last one I built is off my bedroom, which is really nice! I get up and go prowl with my coffee, still in my jammies!!
by connecting to the house, you can buffer the gh temps simply by opening the door to the house...
you will want to allow space for a bistro table and chairs, though!

by making your roof tall, you allow the heat to collect at the top where it can be rapidly removed by your exhaust fan..a gh can heat up rapidly...and that is dangerous!

once you have everything set up, it takes a bit of a 'balancing act' to get all your equipment working together. you decide your temp and humidity parameters, and use thermostats to adjust them in co-ordination....
for me, using cedar and polycarbonate worked just fine...try out several different scenarios on paper and in your head, researching a year ahead of time is great!

dounoharm: Re leanto, I am very concerned that the humidity will encourages wood rot in human house. CA is all wood-frame houses b/c of earthquakes.

I hear you re fiddling. That I know. I have a mini green hut (4x9') right now. That one is also a wood one, but now want to go metal. Glass vs. poly is both an esthetic thing, and low E glass has better R value than even triple poly.

I bought a custom designed kit for Sturdi-Built Greenhouse Company, in Portland OR, and its wonderful.

I've seen some Sturdi-Built ones, and they certainly are nice. However, they are made of wood, which I have ruled out. My current Santa Barbara Greenhouse is also made of wood, no problems yet, but for larger ones, I want be on the safe side. Only metal-glass construction are on my list.

Try BC greenhouses.

Interesting. Seem to have much of the same lines as Gothic Arch, some even identical pictures on both websites! will be interesting to see if prices also match.

This is who builds really nice ones in our area:

https://arcadiaglasshouse.com/greenhouses/

They hand out brochures at orchid shows.

Thanks for that one. Geneva series looks the same to what Florian has. The Sierra is different, though not sure what it means. Sent inquiry!