We recently did an extension to a meat processing factory and the system they used seems rather inexpensive for anyone interested in making a larder /chiller at home.
The whole inside partitions are made up of insulated pannels fixed on a u bracket,cut with a knife or saw and fixed in place.
These insulated pannels can be fitted to existing walls or inside your shed,garage and claded externally.
I've put the link if anyone is interested and thought it might be of interest to any one.
or you coul buy an old refrigerated lorry chiller unit.
It might be of interest to anyone.