"Linear Foot/Board Foot" describes a "Running Length of Wood" (or whatever) so U need first to measure the distance around the house to come up with a number. Now actually measure the "Width & Thickness" of the Wood already there. It won't actually measure say 2"X4" it will be smaller, but called a 2"X4" Ok? Just as a 2"X6", 2"X8", 2"X10" are not their "Finished Sizes" anymore. Now call the Lumber Yard & tell them how much of what size wood U need & they will give a Price. This does not hold true if U have to cut the "Rafter Ends" off a bit due to "Rotting". U can use "Nails" to re-install the wood, but better would be "Bugle Headed Stingers" or "Deck Screws" at least every other "Rafter". Labor will vary by area so if U live along the "Border" where "Mexican Labor" is cheap it might not cost much at all??? Good Luck. John
