Builder converted attic in new house !

Builder applied for mixed development of split level houses over three levels. On one section of the site he submitted revised drawings for one house type where he ” removed the gable windows and eliminated accommodation in the attic.” Elevations show no windows in attic gables and no Velux windows. Roof plan showed 2 Velux windows but I believe that this is a drafting error.
Plannning permission was granted in accordance with the revised drawings.
During the course of construction, the builder put in 2 windows in each gables.
Complaint was made to Council and they served a warning notice on the builder. He closed up the gable windows at the rear of the property, where there had previously been an observation at planning stage.
The Planner did not make any reference to the 2 windows in the roadside gable nor did he seem to know that the atttic floor had been converted.
The attic now had 2 gable windows and 8 Velux windows. It consisted of three bedrooms and a bathroom and was approximately 100 sq. metres. The cill height of windows in 2 of the bedrooms was nearly 1800mm off the ground.
The builder showed the purchasers an as-constructed floor plan and two of the houses were sold. This drawing does not exist on the planning file and therefore cannot be covered by a Certificate of Compliance.

I know that there are other threads about the conversion of attics but I presume that the works described above cannot be exempt in view of the planning history.

I look forward to your comments.