Reduce Energy Costs:
When people search the internet for the phrase “How to insulate an attic hatch” their more than likely concerned about their home heat retaining efficiency, or lack thereof.
Attic hatches are a huge source of air leaks and radiant heat loss. Heat rises and you can bet your paycheck that your losing a ton of heat through an uninsulated attic hatch. Many people do not realize just how easy it is to insulate them.
If your not sure and are one of those folks that need to be shown actual heat loss than I recommend using a thermal imaging thermometer to test you’re attic hatch efficiency. 
Imaging Thermometers allow you to monitor and detect excessive or inadequate temperatures of building systems and envelopes. Allowing the monitoring of energy loss, building HVAC and electrical systems diagnostics. as wall as help locate heat pipes in walls and floors.
Insulating An Attic Hatch:
When it comes to attic hatches there are all sorts of commercial products that you can purchase but most work best with pull down stairs and want to be seated on a plywood floor base. You certainly could deploy one of these products.
If you are interested in saving a few bucks and doing it yourself it is a fairy easy project.
There Are Two Types Of Hatches:
The two hatches where this system wok well on are life up hatches and hinged hatches, but this system also works well on eve doors or interior doors that enter into cold attic spaces.
The Insulation Process:
Many uninsulated attic hatches are simply pieces of two foot by two foot plywood sitting on top of finish molding. This makes them a prime target for attaching rigid insulation to them. To insulate an attic hatch I suggest using rigid insulation and screw the insulation board directly to the hatch.
Steps:
1. Measure and cut the insulation board so that it is a snug fit when the hatch is closed. Rubber weather stripping can also be added and a locking hasp to keep the attic hatch pulled tight against the weather stripping. See Uninsulated Attic Hatch Solution
2. Use ceiling washers or large washers to resist the screw from tearing through the insulation board. I also suggest using aluminum foil duct tape to cover all seams and edges.
3. If spacing and circumstances permit I also suggest adding a second foam insulation box above the hatch similar to the one seen in this article.
4. If your able to create an additional box above this hatch in the attic or lay down some additional insulation over the attic hatch. The more insulation the better!