I will bet if you had 16 inch center rafters it would be as easy as advertised. I have 20 inch center rafters and it was much easier to install in the attic. Also, I needed to purchase a 4-6 inch HVAC adapter to hook into existing 4 inch duct. Oh and by the way HVAC foil tape will not stick to the included 6 inch duct adapter. I had to use a bunch of the best duct tape from Lowes and a lot of it to ensure no leaks in the future.