Disclosed aspects relate to managing a set of spatial zones associated with an architectural layout. A first spatial zone of the set of spatial zones is detected. The first spatial zone has a first spatial zone size value. By comparing the first spatial zone size value with a threshold spatial zone size value, it is determined to convert the first spatial zone. Based on proximity, a group of conversion candidates is identified from the set of spatial zones. Based on the first spatial zone and the group of conversion candidates, a second spatial zone is determined using an architectural criterion. Using the second spatial zone, a design-model of the architectural layout is established.