Both plastic and metal sheds have pros and cons that make it hard to say which is a better choice. If you are looking for the most cost-effective option, you may want to consider a metal shed. Plastic and metal share some characteristics: both are durable, rot and insect resistant, and difficult to customize. Plastic sheds outperform metal sheds in two areas: they hold up better to water (rarely springing any leaks) and do not rust. A plastic shed will be the better choice if you live in a wet climate.