There are a couple of ways to add height to a platform bed. You might consider placing a durable foam mattress base underneath your mattress. This can add a little more cushioning as well as raise your mattress a few inches. Another option is a set of bed risers designed for platform legs. Attaching the risers to the platform’s legs can add up to 12 inches to the height of your platform. Just make sure you get risers that can take the total weight of the platform, mattress, and all sleepers who will be using the bed.