Abstract: A connection device for building structures preventing progressive collapse. A pull means (1) incorporated in the device is adapted to be connected to a part of the structure by means of a cast compound that allows controlled slippage of the pull means at a tensile stress in the pull means which is below its ultimate tensile strength. The pull means is provided with an anchoring means (2) which after abutment against a stop means (3) stops slippage after a predetermined distance.

Abstract: Air condition control for buildings, having a roof structure of roof trusses relatively widely spaced, between which self-supporting roof plates are laid and covered by a covering layer so that a gap is formed between the covering layer and the roof plates. Air is passed in one or the other direction through a ventilation opening in the roof, through the air gap (13) and through ducts (9) in the roof plates. Air sucked in from the atmosphere through the ventilation opening passes through the ducts to an air conditioning unit (5) and to a distribution device (6) to maintain a suitable temperature in the building. Air flow can also be inverted by being supplied in the form of outdoor air to the air conditioning unit (5) and after its passage through the building being conducted away into the atmosphere through the roof structure by the ventilation opening.