I don`t want to sound alarmist. The building work has been going on for a considerable time, Thomsons are having a laugh. I work in construction and can assure you that this work will continue for some time. As regards the dust you should be fine with the balcony door closed your air-con will shut off if you open both sides anyway. Our first room balcony was covered in dust , depends on wind direction, our second room balcony was clean. Noise may well be the biggest problem , starting from just after 7 am six days a week. The hotel main entrance faces inland , the reps certainly know about the building work. If your lucky it may be the trades holiday. The building site is in the adjoining property and although we took pictures I wouldn`t have a clue how to post them. From our friends balcony, room 230 I think, you have the view of the shell of a newly constructed building .