A Trinity House will have a few reasons. Based on my assumptions of 25′ × 50′ – this is a smaller lot size (average for Pittsburgh). A Trinity House offers a place to run utilities into. It also gives a bit of outdoor space, and being that I live by myself, it gives me the rooms I need – even if they are dedicated on their own floors. The Trinity House has more square footage than the Live-in Garage which is only 625sf. The Trinity House will be new construction, so everything will be constructed in a modernized system rather than the ones found in Philadelphia.