Insulating a cold bedroom over the Garage - "Heated space"

We recently moved our bedroom to a larger one at the front of the house. This was a concern because it was notoriously the coldest room in the house. Its always several degrees colder.
This is a common problem in Canada and there are many service companies do it yourself solutions.
I of course hate paying anyone to do something I can do myself.
So with unused vacation time I had to take before the end of the year I was determined to solve it as inexpensively as I could.
Inspection:
To start I cut some holes in the garage ceiling drywall large enough to stand on a ladder and look around with a bright light.

Then I cut out sections of drywall between the studs.

I was happy to see there was already considerable thickness of pink insulation, however what I saw next changed my whole plan.
I knew I would see the two heating ducts and figured I would need to wrap them with insulation, however there was a third duct just blowing into the space. 
Seeing this I wondered why the space was so cold.


Change of plan
I was thinking of purchasing a spray foam kit and apply it directly to the underside of the floor. Now I realized if I did that I would loose the benefit of the heated space.
So I needed to find the cold areas and improve the insulation.

I could see the insulation on the side walls was not as thick and I could see the builder has not put vapor barrier over them .
So, this was enough to send me off to my nearby Home Depot to buy insulation. I selected Roxul R22 16 inch wide.

Three bats fit nicely in the back of a 2003 Honda CRV. They also come bundled in 3's.  I later went back and go one more.

Also notable, the plastic used to tie 3 bundles together is heavy enough to use for extra vapor barrier.

I slid down the short stubs of insulation and added more insulation above in the outside walls.

Then I added vapor barrier plastic. 

Then I placed more new insulation on the warm side.

Back in the garage ...Outside of the front of the house has a steel I-beam.

After cutting some more access holes I got a better look.
From inside I could see the I beam exposed in the corners, so clearly not enough insulation inside,




I ran a new full thickness wall of new batting along the outside walls.

In the most interior wall I saw plumbing so I had to ensure i didn't cover it. it had to stay on the warm side of the insulation.

As a final layer of warmth I split several bats of insulation to half thickness and layered over top of the  original pink insulation.

The end result is that I feel much of the house is warmer and I expect a better heating bill this year.