The most common garage door material is aluminum, but the best material for you depends on your budget and location. Wood is the most expensive to repair but tends to add the most curb appeal, while fiberglass or composite doors cost less to fix.

Aluminum won’t rust, so it’s a great option if you live somewhere humid or rainy. Steel doors are durable but are prone to rust. If you live somewhere with extreme temperatures, hot or cold, you might opt for fiberglass, which won’t split if the temperatures skyrocket or drop below freezing.

For a garage to be included in a home's official square footage, it must qualify as livable space. This generally means it needs to be attached to the home and have permanent finishings like proper insulation, finished walls and ceilings, and adequate ventilation. To be considered livable year-round, it should also have heating and cooling. The specific legal requirements can vary by location, but if a garage is converted into a finished room meeting these criteria, it may be counted toward the total square footage.

Sheet metal garage doors, particularly steel and aluminum, have the cheapest materials and installation. Experienced homeowners may cut and shape the metal themselves; however, you can buy prefabricated metal from a hardware store or pay a metal fabricator to shape the metal to your specifications. Steel and aluminum garage doors can cost as little as $500 and go up to $3,000.

In most cases, you do not need planning permission to change a garage door to a normal door, unless a specific restriction is present on your home’s deed. If you’re changing the door because you are trying to convert the garage into a living space, you will need to work with building control for proper signoffs to ensure your conversion meets all of the necessary construction standards.