portion 22 while maintaining the same in fixed and spaced relationship relative to the supporting structure as a feature of the invention as will be described in greater detail hereinafter there is provided a shed 42 this shed which may be fabricated of aluminum steel wood plastic or the like extends in partially overlapping relationship with the glazing structure 10 at the top edge portion 22 the function of the shed is to protect the opening 30 from the penetration of hostile environmental elements such as rain sleet snow and the like it will be noted that this function of providing a venting opening while protecting the same against the penetration of hostile elements is accomplished without interfering with the function of venting the interior of the glazing structure 10 while at the same time there is little or no possibility of penetration of these hostile elements as is possible with the roofsash type venting of the prior art in the glazing structure 10 there may be provided conventional doors or other such openings as may be desired these are not illustrated and if incorporated in the structure of the invention will be so incorporated in conventional form the front.