I have a large greenhouse. Two roof windows with automatic vents and another 3? 4? that I can open manually, and wide double doors that I leave open in summer. Bubblewrap in winter - the canes running the length of the roof that support the bubblewrap double up as plant supports in summer.
I have light, power and an extension for the landline. And a comfy chair (actually, two). And an old umbrella in case it starts raining when I'm out there, so when I go back to the house I'm not soaked.
Most of the plants are on staging, except for one section where I have a tub on the floor for the cucumbers, which then climb to the roof. Under the staging is where I store pots. There's nearby water butts collecting from the garage roof, so I don't have to walk too far with a watering can, and a tap outside for when the rainwater runs out.
In winter it has overwintering plants, then from early spring seedtrays of veg and flower seedlings. At the moment there are cucumbers, tomatoes, lettuces where it's cool near the door, and various other salad leaves, courgettes which I'm guarding from slugs, a cape gooseberry, and lots of young plants being cossetted until they can be planted out. And cacti.