The building footprint is a round shape; circular, elliptical, or ovoid, and it has an interior open courtyard (whether roofed or not).


Beijing National Stadium (also known as the Bird's Nest) has a circular plan shape with an opening (Map data ©2013 Google, DigitalGlobe)

Date of construction can be taken from when the building was completed. If the building consists of structures that vary in age, use the earliest date. If the structure of the building has been upgraded (retrofitted) in a manner that improves its seismic performance, enter the date of the retrofit instead of the date of construction.

The foundations are 1m deep or more below grade, and they have lateral capacity. Foundations with lateral capacity include tie-beams, foundation walls, inclined piles, piles or piers on wide spread footings.


An example of a braced timber pile deep foundation with lateral capacity. This example is a deep foundation that is braced. Another option is for the deep pile not to be braced but to just act as a vertical cantilever provided the height of the pile is not too great above ground level.

The foundations are 1m deep or more below grade, and they have no lateral capacity. Foundations with no lateral capacity include piles without lateral bracing support.


An example of a timber pile deep foundation with no lateral capacity.

Where it is possible to specify directions, Direction X is parallel to street, and Direction Y is perpendicular (orthogonal) to street. In some cases, it is not possible to identify Direction X and Direction Y - thus the user can select Unspecified Direction.