The Ultimate DIY Garden Cold Frame?

This was my Christmas project and the structure is approx. 10' x 4' (3m x 1.2m) with the high side being just over 1m (3'3") and the low side being approx. 0.5m (20").
It is made from a 2" x 2" (50mm x 50mm) frame and is covered by 6" x 5/8" (150mm x 16mm) boards with 2" x 5/8mm (50mm x 16mm) lappers over the board joints. The actual size of the '2" x 2" is nearer 45mm x 45mm as they are dressed (planed).
The cold frame sits on a base made from pressure treated fencing rails which have then been treated with creosote. That keeps the cold frame approx. 1.5" (40mm) above the ground so the main structure is not in contact with wet and dirt which could accelerate the wood rot - this should last for decades.....
All wood inside and out on the cold frame is pressure treated but since pressure treatment isn't what it used to be (I'm planning a 'rant' video on that subject) it was all then treated with a spirit based timber treatment. Avoid water based 'treatments' as they are useless.
The spirit based timber treatment can be found here: https://geni.us/95NKT or on the A-chem website here: https://www.achemshop.co.uk/product/timbashield_dark_oak/
The gas rams I used to enable easy lifting of the lids can be found here: https://geni.us/LsyNSHd
The Stainless steel hinges used on the back of each lid can be found here: https://geni.us/2NWw5F
There are 4 hinges on each lid.
The handles on the lid can be found here: https://geni.us/gBuPQ3
All the screws used are outdoor screws which are zinc coated and are available from any decent DIY store. Same story for the zinc plated bolts used to hold sections together (they are 125mm x 8mm).
The cold frame sits over the overflow from my sewage tank so there is some low level heat being generated underneath it from the bacterial activity - that will help it stay frost free over the Winter.
I'll be covering the bottom of the cold frame with some heavy rubber pond liner as I have a spare piece which should be big enough..
I will do semi-regular garden update videos so subscribe if you want to see more on this project and the garden.
Thanks for watching and check out the gardening playlist on my channel for more videos.