Here in NJ if this is a public place, the sconce lights can not be hung too low. A visually impaired person might hit it. There is a law here in NJ that is American Disability Act (ADA) and that tells you at what height these sconse can be installed at. Now if there were some window planter boxes or something like that to prevent somone from walking into the light, then the height would be determined by the plans, architect or engineer.
