We are currently living in our second old home. It was built in 1918 and has kind of a Dutch Colonial architecture to it. We love older homes because of the attention given to the architectural style many older homes display.
But along with that attention to detail, comes, many times, a lack of attention to temperature preservation. Drafty windows, no insulation in the walls, and often a furnace that is undersized, means you will get chilled on days like today.
Here's an idea I wish someone would pick up on...and quick, especially for those homes who still have single-pane windows. A clear, spray on window covering that would blanket the entire casing of the window on the outside. This product would cover the trim, cover the glass, cover the cracks...cover it all. It would be much different than the clear, roll on, hairdryer wraps you put on the inside. Those products may act as that second pane of glass, but do little to help the cracks. This new product could be as thick as 1/4", but really, it could be as thin as it takes to cover the window and not make clumps. Also, formulate it so that, when it get peeled away, it doesn't peel the paint or existing caulk. It would be clear to allow natural heat from the sun to come through. Lastly, it would be recyclable, so every year, the service company would come to spray it on before the cold months, and come to peel it away in the spring.
Our first house had about 24 single-pane windows. It was a drafty house, but we couldn't afford to put new windows in. This kind of a product would have saved us in heat bills, but definitely would have kept us warmer.