If you own and older of Historic home you have probably received that first "BIG" winter heating bill and you may be scrambling to find ways to better insulate your home. However historic homes present unique challenges. For example you DO NOT want to replace original windows with thermopane windows.
Aside from destroying the value of your historic home, they area high cost item, (typically 8-12,000 for the typical home), replacement windows do not 'last"( seals on replacement windows typically fail with 7-10 years) and you may NEVER actually recover the cost of install during the life of the windows in reduced heating costs.
A greater savings can be realized by properly caulking insulating and glazing your original windows, as well as other low cost repairs.
The National Trust for Historic Preservation has a new page on its website dedicated to Weatherization tips for older homes. Everything from roofs to heating and air conditioning systems plus download 'Tip sheets" on topics like "15 easy steps to prepare your home for winter" or 'Ten reasons to repair old windows"