For a developer capital costs are the main factor, as operational and maintenance costs are passed to the tenant. With glass technology improving, the solar rad

For a developer capital costs are the main factor, as operational and maintenance costs are passed to the tenant. With glass technology improving, the solar radiation component onto the HVAC system is now not much different from a traditional façade. After all there is no roof heat gains, other than on the top floors and maybe partially on some others. For the most part of a floor the heat gains for HVAC is lights, equipment, people and the cost of cooling the fresh air. People also add to that load. On the civil side, glass facades enable thinner floor slabs with the gain normally of some extra floors. I have been involved with many high rise buildings and they are highly complex beasts to get right everything, especially the costs. With flat slabs one can cast a floor on average every 7 days.