HI.I am thinking to add conservatory at rear in between house and detached garage.whats max size allowed under pd.also can we go on boundary wall to neighbours side.we already have solid stone 6ft wall built on neighbours side.this wall is on our side from boundry line.this way we have three side walls already built so we can add gloss frontage and roof.whats best way to sound proof conservatory glass roof.the reason neighbours have big noisy dogs and adding conservatory at rear would ground floor much needed piece and quite.