What should I insulate first?

My husband and I own a home that is over 150 years old. At least one of the rooms is the original plaster and lathe, but some of the rooms have been redone with sheetrock or aren't part of the original house. It's a central chimney cape. The first floor is full, the second floor has sloped ceilings and knee walls with attic space behind the knee walls accessible through small doors.



We don't have a lot of money for this project so need to do what will get us the most bang for our buck and everything else can wait until later.



We are going to get some of the door and window foam sealer to go around all the doors and windows to start, and we will be shrink wrapping the windows and the large sliding glass door.



This is what we want to insulate:



Nothing in the cellar is insulated (we can only do around the floor as it's a fieldstone basement that gets wet) including the floor, around the footing, the windows (which are very old), anything.



As far as I know of there's no sheathing outside (my olive oil in the cupboard goes solid) or insulation on the interior side walls.



There is 3" thick hard foam insulation on the floor of the attic that has gotten wet from the roof leaking on it. Mostly it covers the floor but there are gaps (so obviously the heat from the floor below comes up through)



There are batts of insulation on the unconditioned side of the upstairs knee walls (in the attic)



There is weather stripping around the edges of the attic doors and a piece of the rigid insulating board behind the doors.



What should be the priority to save energy this winter?



I live in Maine and it gets pretty cold and we have a wood stove for heat because the forced hot air system is pretty useless.What should I insulate first?
Highest priorities should be any areas that actually let cold air in or which feel unusually cold in the winter. Hot air rises, so all else being equal you want to insulate the ceiling first, then walls, then floors. Walls are usually the most expensive to insulate, so if money's tight you may want to save that for last.



Foam insulation typically does not hold water, so the insulation in your attic should be OK.



Do your furnace and stove have outside air intakes? If not, they can draw cold air into your house.What should I insulate first?
Insulate the attic First for sure, it is the most important place to insulate. Why? In the winter, cold air falls downwards and the attic is your first line of defense against the cold air falling straight down on your roof. And, in the summer, the hot sun is constantily beating down on your roof, so in the summer time, the attic is again your first line of defense.

Realistically, no matter how much insulation you have in your attic, more is even better.

Styrofoam sheets verses Fiberglass battings. -- Fiberglass is a lot cheaper per R value. However, if you have very little space to place your insulation then strofoam is higher R value per depth (per inch).

For example: To Get an R value of 11 - you need 6 inches of fiber glass or 2 inches of Styrofoam -- But the styrofoam will cost you twice as much money to achieve an R value of 11. --