The traditional style greenhouse or glasshouse has been around for a long time they are both spacious inside and can be built to a variety of different styles and configurations and are very durable, the Poly tunnel style green house is more cost effective to build but not as durable and strong as the traditional greenhouse ofthen requiring a lot of maintenance.
Glass Panals, The traditional style greenhouse can be enclosed in two very different materials, the classic glass which is fragile in high wind zones and can break when branches etc fall on the panals, glass due to a high heat transfer rate does not retain any heat trapped inside during the day and loses all this heat at night and glass panals need to be toughened for reasons of servere injury should a panal break over your head, advantages of glass are durability a more traditional look and very good light transfer to the interior, disadvantages, fragile, poor thermal retention and possibility of burning plants in bright sunlight.
Polycarbonate, The traditional style greenhouse can also be enclosed with polycarbonate, this material is super tough compared to glass and polycarbonate is constructed with an inner wall and an outer wall with a sandwich of polycarbonate material in between, this twin layer provides a low heat transfer to the outside making it more thermal efficient, advantages include very durable and tough, excellent thermal efficiency and the light entering the greenhouse is diffused avoiding burnt plants. Disadvantages the polycarbonate is easily scratched, mould and moisture can enter the flutes on the surface.
Poly Tunnels, Poly tunnels are constructed from a plastic tubing frame work which supports a membrane of plastic film over the top, the poly tunnel is used more by commercial produce growers as the cost per square meter is alot cheaper than either the traditional glass or poly carbonate, however the plastic film does not last as long, the uv sunlight will destroy the plastic in around five years needing a replacement, although the plastic is strong it is prone to ripes and tears, advantages low cost and diffused light, disadvantages include short life span and poor thermal efficiency.