Stackable washer-dryers may not be cost-effective if the washer breaks before the dryer or vice versa. It is also important to consider efficiency options such as front-loading versus top-loading washers, gas-powered versus electric-powered, and the units' energy ratings.
Stackable washer and dryer pairs tend to offer fewer features than the washers and dryers sold individually. They may also require an electrical upgrade to a 220-volt power outlet. To get around those issues, some consumers buy washers and dryers separately and then manually stack them with a stacking kit. As of 2013, these kits range in price from $15 to $50.