Durian's comment that Japan hadn't even registered on its own "National Heritage List" the Le Corbusier building it was being asked to nominate has set me thinking that it might be interesting to explore and pull together the various "National Heritage" registration systems in use in different countries (and the relationship between these and their WHS list)
I always remember being slightly "amused" in S Korea by the little plaques giving every building of importance a reference number within some great list of National Treasures - but, on reflection, we in UK have something similar, albeit without the Numbering system!!!
For "Buildings" UK has a system of "Listing" - and, once a building is "listed", there are considerable restrictions on what can be done. Some "owners" find their houses so described (it can even be done in "an emergency" almost instantaneously) and face enormous (and some might think excessive) restrictions.
There are 3 categories of Listing (the system is described in outline here http://en.wikipedia.org/wiki/Listed_building
Grade I: buildings of exceptional interest
Grade II*: particularly important buildings of more than special interest.
Grade II: buildings that are of special interest, warranting every effort to preserve them
I have been checking through the list in Category I (of which there are over 6000 entries) against the UK's World Heritage List. Some structures aren't on the list because there is an earlier list for "Scheduled Ancient Monuments" ( http://en.wikipedia.org/wiki/Scheduled_Ancient_Monument
) by which sites such as Stonehenge are protected. I have found all the other major buildings on UK's inscribed list which I have searched for e.g Pontcycyllte Aqueduct, Blenheim Palace, Tower of London etc etc. I couldn't imagine that UK would nominate any site which was not , or whose major buildings were not, "Grade I Listed" or "Scheduled National monuments". indeed within a city like Bath there will in addition be hundreds of Grade II* and Grade II buildings as well.
Herewith the UK Grade I list by categoryhttp://en.wikipedia.org/wiki/Category:Grade_I_listed_buildings_by_function
Since we reached this subject via a consideration of "Modern" sites which might become WHS I have researched which modern buildings in England (I haven't yet found the Scottish etc lists) have already been given Grade I status. Here is the list (unfortunately without construction dates)http://en.wikipedia.org/wiki/Grade_I_listed_modern_buildings_in_England
A few to point out
a. Severn Bridge (1966)
b. Jodrell Bank Telescopes (50s/60s) - were considered for new UK T List
c. Willis Faber building (Foster Assocs 1970-5)
So, perhaps still a bit "lacking" in really modern structures - but the system normally only operates for buildings over 30 years old (so UK considers that, in general, one can't decide on the merits of a building in less than this time) However special arrangements CAN be made for buildings over 10 years old and the Lloyds Building is under consideration on this basis!! http://www.guardian.co.uk/artanddesign/2011/jul/12/lloyd-s-building-grade-i-status
What approaches do other countries follow and are there web sites where we could look at the buildings concerned?