Work on the cathedral will include the rest of the interior up to the altar and remaining stained-glass windows and new heating and air conditioning systems.The third phase will begin in the fall of 2013 and include the altar and the Lady Chapel behind the altar.Bast said 250 to 300 tradespeople will be working on the site, and up to 1,000 people, including consultants, overall.St. Patrick's Cathe