A building design is said to be proposed when it fulfills all of the following criteria:
1) Has a specific site
2) Has a developer/financier who owns the site
3) Has a full professional design team who are in the process of progressing the design beyond the conceptual stage
4) Has a dialogue with the local planning authorities with a view to obtaining full legal permission for construction
5) Has a full intention to progress the building to construction and completion
Only buildings that have been announced publicly by the client and fulfill all the above criteria are included in the CTBUH "proposed" building listings. Due to the changing nature of early stage designs and client information restrictions, some height data for "proposed" tall buildings that appears on the CTBUH "Tallest" lists is unconfirmed.