Is it a film you're directing? If so, something simple like "The entire facade fills the frame" or something like that which would cue you on how to shoot it. If you're not directing, don't worry about it, that would be the director's choice. A writer shouldn't direct in the script. In that case, use words like "an imposing building" or whatever to indicate the scale or importance, while leaving the choice of how to interpret that to the director.