In my work as an historic buildings specialist, I am often asked energy conservation questions such as, "How do you insulate an old house?" My usual reply is "What is the best way to get to New York City?" There isn't any single answer to either of these questions. Just as one may be able to walk, drive, fly, or ride the bus or train to New York, many factors influence the decisions which are made leading up to the correct application of energy conservation measures to old buildings.
Technology today is totally different than when most of the buildings on which we work were constructed. What isn't different, though, is that the people who live in, and use these buildings, want the interior to perform up to the current standard of comfort, whatever the weather is doing outside. Of course, the standard of comfort is significantly different now than it was one hundred years ago. And the standard in 1895 was significantly different than it had been in 1795. At one time it was just part of life that if you had water in your bedroom in the winter that it would freeze.
18th and 19th Centuries
Until central heat became common, it was not unusual to heat only one or two rooms. Doors were used to close off rooms and hallways to "zone" heating only to those areas which were currently being used. Warmer clothes and lots of bedding were the norm.
In the south, porches shaded the windows from the sun. Kitchens were often in a separate building, and it wasn't uncommon for windows to be large so as to allow for freer air movement. The cupola is an architectural feature that can still be seen today on innumerable Victorian houses, both in the south and north. By opening windows both in it and in the lower living areas, it created a chimney effect that pulled cooler outside air in and exhausted the warmer air to the outside.
There are other things that could be mentioned but the common thread is that most of these things cost little or nothing to operate, consumed few, if any, natural resources, improved the comfort level of the buildings' occupants, and could be utilized today in our high tech world.
Modern Alternatives
Vinyl siding is a product that gets a lot of "bad press" from the preservation community. I must admit that I am always disappointed when I see that someone has decided to cover their antique building with it. Too often it obliterates and/or replaces the features and details that give old buildings their charm and character. But I don't automatically think of it is as an inherently a bad product. Aside from the aforementioned, my objections stem from the fact that it often is installed to cover a symptom instead of determining what the actual problem is and correcting that. For example, if you are having a hard time keeping paint on your house, there may be a significant moisture problem. Covering it with siding only takes care of the symptom, you still have a moisture problem which needs to be addressed.
Windows are another area of concern. We often rebuild existing antique windows instead of replacing them and sending them to the landfill. It is usually very cost-effective and an important decorative feature of the facade is preserved. Sometimes, usually when the original windows are gone, replacement is an appropriate action. We always try to replicate the size and configuration of the originals. Make an informed decision. There are many options available.
Back to the insulation question. Many factors, such as electrical, plumbing, and heating system conditions, along with budgetary considerations, enter into what approach is to be taken. Insulation is commonly done from the inside but can be done from the outside if you have an interior that is fine and an exterior that could use a major rehab. There are a large number of products and installation methods from which to choose. And again, incorrectly installed insulation can potentially do more harm than good. In fact you need to look at the whole building as it functions as a unit, not just the individual parts. For example, stopping all air infiltration from the living space into the attic will often have a significant effect on how drafty the windows in the building are and it may also help with paint retention on the exterior of the building.
What to do?
Copyright © 1998 Jeff Finch
Practices that are unheard of today (or at best considered low tech) were, in the eighteenth and nineteenth century used to conserve energy and/or alter the interior environment. What today are usually called shutters were known as blinds (shutters are solid with no louvers). They were found both on the exterior and interiors of buildings hung on functioning hinges, not just nailed to the siding as decoration. When the blinds were closed in the summer, air could circulate as the breezes dictated, a usable amount of light was allowed (remember the standard of lighting levels was different too), but the heat gain from direct sunlight was excluded. Often, especially from the 1860's on, there were interior shutter/blinds that could serve the previously mentioned function in summer but in the winter, when closed, would create something of a dead airspace between them and the windows, which served as insulation. Roller blinds or shades were probably even more common and, again, could be used to exclude heat and cold as well as to preserve privacy.
The products which are available to us today are almost innumerable. Some things are combination decorative and functional, and some things are purely utilitarian. But like the man seen sitting on a beautiful horse facing the "waste" end, the best technology can be useless if you don't know how to correctly put it to use. Each material has its own properties, advantages and disadvantages. If you don't understand all of them and use them in an incorrect application, you could actually do more harm than good. At best you may spend a lot of money on a product or service that isn't necessary.
The bottom line is to do some research and thinking. What seems good today may not have half the lifespan that the item you are replacing already has had. Listen to what you are being told and ask yourself, "What is the actual meaning of the statement?" A long guarantee is only as good as the one who is making it and even if they will make good, what is it that you will receive five, ten, or twenty years from now if the product fails? Often, if you know where to look, there are economical solutions to problems on which you can otherwise spend a lot of your hard-earned money for little return, and usually it will be a more environment-friendly solution