Wood siding and vinyl siding are essentially different species. In the end, a decision between the two almost always comes down to aesthetics versus price. The aesthetics gap has closed to some degree in recent years, as vinyl siding manufacturers have gotten better at imitating the look of wood. Still, almost all groups that set the rules for building and renovation in historic neighborhoods place vinyl siding at the top of their "banned" list.
Homeowners faced with a choice between wood siding and vinyl siding need to ask themselves whether the appearance of their house would be improved by using wood and if they are prepared to devote the time and/or money for the regular maintenance that wood requires. The obvious advantages to vinyl siding include durability -- since the paint isn't externally applied, it never chips or peels -- and price --generally considerably less than wood products). Obviously, vinyl is unattractive to termites, and is impervious to the moisture rot that often plagues houses with wood siding. On the flip side, wood siding provides better insulation. Also -- and here is where aesthetics rears its lovely head again -- the installation of vinyl often obscures the trim details that give a house its individuality.
The marketing battle between wood siding and vinyl siding continues unabated, with both camps working to overcome their built-in disadvantages. Wood siding manufacturers are trying to make their product more durable, vinyl companies are seeking to overcome vinyl's image as "cheap." Wood siding and vinyl siding also have a new competitor -- Hardiplank®, which is a composite of wood and cement that incorporates some of the advantages of the older wall coverings. Builders can also offer galvanized metal.
Generally, wood siding needs to be painted at least every four years. It is also a good idea to keep moisture off it whenever possible, since that is what gives birth to the telltale dark stains of rot. Properly functioning gutters are a key in this battle.
Environmentalists are torn on the merits of wood siding and vinyl siding. The former, obviously, requires the destruction of trees. But where old wood siding can be recycled as firewood, vinyl doesn't burn -- another advantage while it is in place -- and can be difficult to dispose of. The good news is, that may not become a problem, given its longevity.