Vinyl, also known as polyvinyl chloride or PVC, is widely used for siding due to its relatively low cost, low maintenance, and easy installation. However, the process required to manufacture vinyl siding is highly toxic. The chemicals used in the production of PVC have been linked to a variety of health problems including respiratory problems, liver and kidney damage, birth defects, and cancer. The end product can also give off dangerous gases, particularly when burned. In addition, vinyl is not biodegradable and it cannot currently be recycled.
Wood siding is attractive, but is often more expensive than other options and requires extensive maintenance. Wood siding is also susceptible to rot and termites. Another option is using wood composite siding, which is made from wood chips or shavings and is often more durable than ordinary wood. However hardboard, a wood composite material, is not recommended for use since several manufacturers are currently involved in litigation over the rotting, discoloring, and buckling conditions of hardboard. If wood siding is used, it should be approved by the Forest Stewardship Council, which certifies wood that is derived from renewable sources and is the result of responsible forestry practices.
Engineered siding materials
Fiber-cement siding such as Hardiplank lasts longer than wood and is better for the environment than vinyl. However, it must be installed properly in order for its benefits to be realized. Fiber-cement siding is durable, stands up well against harsh weather and is resistant against termites. Another benefit of fiber-cement siding is that it is fire resistant. Fiber-cement siding can either be purchased unprimed, pre-primed, or already painted. Fiber-cement siding tends to be cheaper than wood, but more expensive than vinyl.
Other options include brick, stone, aluminum, or stucco. Each of these depends on the climate, cost, and durability desired. Many of these materials can be attractive exteriors, but are often more expensive than the other materials listed above.
(sources: City of Austin Sustainable Building Sourcebook, Green Building Guidelines for New Home Construction, "The Lifecycle of Vinyl: Past, Present, and Future Harm" by Blue Vinyl)