Insulate rafters or build and insulate a ceiling?

[AW716]

I am currently debating on what my best option would be for insulating the top half of my garage. I’ve been weighing pros and cons in my head and was curious as to what others have done and find work the best for them. I have thought about insulating the roof rafters. Doing so will involve cutting in a ridge vent as part of the process. Then I have considered putting in a ceiling and insulating that. Only issue I see with that is I have an attic space that will be somewhat difficult to get the few things we put up there in and out because it will only be 18 inches high. However with that lower ceiling I feel that it will be much faster and efficient to heat as the ceilings will only be 8 feet high along with a much cleaner appearance. So with all of that being said does anyone have an opinion on what the better plan of attack would be?

 

[hippie2cams]

i just insulated the rafters on my 10 ft. ceilings and put plywood over the insulation all the way to the peak. When I installed my 3.5t heat-pump it is in the conditioned space. It's been this way for about 2 years now and It is working out well. My garage is a 30x40x10 so I assume your is about the same. Mine is a modified post frame by that it had the slab poured first then the plate and columns erected with 2x6 purlins on 24 inch centers.