It is a plastic kit on the inside and then sheathed in tempered glass that I framed. The front had to be done in wood frame and plastic for this year. It has been below -3F here so far. I keep it 58 at night and it gets as hot as 103 so far in the day time. I have an old scavenged coil electric heater that used to be used to heat a cement basement. So far I am not going broke on the electric bill.

wonderful space! I know you are so glad to have it! it is beautiful!

Awesome!

Beautiful

Nice I am jealous, I would love to have one.

I'm jealous too. My window sills just don't compare.

I am very happy with it.

How do those shelves work?
It looks like you get to cram a lot fo plants in, but does light suffer? Do the ones on the bottom shelves do as well?

This is something I am trying to figure out for my greenhouse, there are obviously some plants that need less light in mine, but am not sure if the bottom shelf will still offer too much or too little light.

Also not sure if I want to 'go up' - I would be paranoid something would fall on me or my collection would fall over if I make a wrong step!

The shelves are the ones I made for my shade house. I was only going to use one on each side, but decided I would need more room. I have 2 sets of shelves stacked on each side. The lower shelves hold my lower light plants. They get pretty good light during the day this way. I do not have as many lights as I should have for later in the day. You could easily attach lights to the underside of the upper shelf to help for the lower plants. I could also put lights under the lower shelf and expand down to the bottom one. I do not have a light meter, but they appear to be very happy as many are spiking.

Very nice, sure looks cozy in there. I've lived in big cities my whole life and never felt the need for a yard...until now. I'd love to have the space for an outdoor greenhouse, good luck with your sanctuary!