Concerning the blessing, “All is done by His word,” the rule is that if he had to stop, he must bless again.
We should interpret that in the rest of blessings over delights, even though he had to stop, he can still bless, since he has something to bless for within reason. This is not so with “All is done by His word,” meaning both what makes him feel good, and what makes him feel bad, “All is done by His word,” as it is written, “And by the breath of His mouth is all their hosts,” meaning over the desire to do good to His creations.
This can be only above reason. And when the building is above reason, for any stop, we must begin the work anew. This is why we must bless once more.