I doubt the architects would reject Hamas contracts (if through the PA of course, they wouldn't build Al Qaeda or Hamas HQ I'm sure). But why is this necessarily anti-semitism? I'm not saying it necessarily isn't but it could be purely political. By claiming it is you are blurring the distinction between anti-Israeli and anti-semitism. Look - some people view Israel's actions as wrong in the OTs. This isn't an implicit denial of the wrongfulness certain Pal/Hamas actions, just that Israel is doing wrong. You might say the double standard = anti-semitism but you also have to consider scale and capacity. Israel is strong, a state, suffers far fewer casualties etc. Pals need help. Some people for non-religious reasons genuinely believe that Pal cause is more justified MAYBE the architects see it this way, maybe they don't (it is a small group I expect, headed by a Muslim, could be anti-semitic). Most British people in general do anti-Israeli, not anti-Semitic.
Protests in southern Syrian city after Druze cleric's death (AP)
from the article: The new British anti-Semitism