How can I measure a width on a building without having direct access to it.?

[mrrusty]

Laser measure - provided you can see the spot from the distance you stand away and the measure can go that far, left side, middle, right side and a bit of simple trig.. The middle measurement gives you a right angle to the wall, so really easy to work out the lengths from middle to left and right when you know the long side (hypotenuse of the RA triangles)

 

[foxhole]

Width of a building from the front often has no bearing on the rear dimensions or the boundaries and can prove very little in regards to a boundary dispute .

 

[Dereekoo]

Laser measure - provided you can see the spot from the distance you stand away and the measure can go that far, left side, middle, right side and a bit of simple trig.. The middle measurement gives you a right angle to the wall, so really easy to work out the lengths from middle to left and right when you know the long side (hypotenuse of the RA triangles)

As clear as mud, now draw us a diagram of what you mean

 

[HERTS P&D]

Google earth has a measure on it.

Andy