The intrinsic engineering issue is the need to avoid fenestration punctures in stonework barrel vaults. The rectangular fenestration on the upper most story were decorated with rustication. It is important to examine these exterior walls for future fenestration and air conditioning ducts. It is recessed slightly from the mezzanine, with its fenestration echoing that below. He re-encased the entire exterior while respecting the original fenestration. The fenestration in an external wall assembly are the biggest wasters of energy. The bottom tier is mostly stone with only a vertical line of very narrow fenestration. The walls and fenestration also affect the views from inside the pavilion. The fenestration is designed to indicate the status of their floor. Details such as the layout of fenestration on the building drew from classical traditions. Other variations such as duplication, triplication, absence, and fenestration are much less common. The fenestration as a whole represents a compromise between authenticity and modernity. One research project is an inhabited adobe house with rational fenestration. In addition, the existing fenestration was unified. Testudines are placed in the subclass Anapsida because they lack fenestration.