But, in her judgement, Ms Pleasant questioned claims the banners were temporary, given they had been there since 2021.
“I am not persuaded the banners installed were the minimum necessary to achieve the aims of health, safety or preservation of the building,” she said.
“While the banners are vibrant, they also appear incongruous on this historic building by reason of their scale, use of materials and advertisement content.”
Earlier this year, the Local Democracy Reporting Service had asked the Planning Inspectorate why a decision on the appeal was taking so long.
The inspectorate said a “suitably qualified” person was needed to inspect listed buildings, and the earliest that someone appropriate could travel to Bradford was in December.
Ms Pleasant said the appellant had not attended the building for an arranged visit on 8 December and so she carried out an unaccompanied visit.
In her ruling, Ms Pleasant said: “The display of the 14 banner advertisements, the subject of the notice, was not so urgently necessary for health and safety, nor the minimum measures immediately necessary for the preservation of the building, that an application for listed building consent could not have been made beforehand.”
Awarding the library building a Grade II listing in 2007, Historic England said it had “special architectural interest” as a public building designed for and by the local authority, which was Bradford Corporation at the time.