Abstract Progressive collapse implies that a local damage on a building leads to a continuing collapse. This can include the whole or a part of the building. It was first in 1968, after a gas explosion in a 22 story building, Ronan Point, London that led to a progressive collapse that made the world aware of this problem and that it needed to be addressed. The event made that certain standards was implemented in several countries to decrease the risk of progressive collapse. The standards for progressive collapse arrived in Sweden 1972. In Sweden there is two standards that concerns dimensioning about progressive collapse, which are 1991-1-7 and 1992-1-1. Although the standards are hard to interpret and design engineers have had to draw their own conclusions. This paper does only focus on rules about vertical and horizontal joints. In the paper the difficulty that comes with dimensioning the different standards are interpreted and made clear. The interpretations that have been made in this paper is suggestions and to show how well the theory is matched to the practice, to showcase this I’ve made some prefabricated cases. The most important conclusions of this paper is: The actors need to have more knowledge about progressive collapse It’s a clear that we need a standardized method, because practitioners are doing it in many different ways Today’s standards need to be supplemented from different areas, which is shown in chapter 5.1.1 There is also further studies needed in this area, progressive collapse Keywords: Progressive collapse, Vertical joints, Horizontal joints, Accidental action