We frequently get a call from a prospective client asking us about adding windowed room for their back yard. In many cases the client is interested in a sunroom that will expand their living space and be usable for 8-12 months out of the year. There are, of course many ways to expand living space on a home, but a sunroom is one of the most popular. Frequently the homeowner would like to put this on an existing deck area. Unfortunately, this strategy can lead to all kinds of future problems. Very few decks have been built strongly enough to support a full room and roof weight. We have seen rooms built on existing decks that created innumerable problems with the existing house and the new room. These problems can include sagging, settling of flooring, roof leaks, and jammed doors and windows. In some cases the existing deck can be braced or supported to carry the extra weight of the new room, but in other cases the cost of the bracing, and the difficulty of installing it can exceed the cost of building a new support structure from scratch, especially if the old deck has any rot or structural problems. Since a properly designed and built sunroom enhances a homes value and usability, as well as expanding living space, it is always a good long-term investment to get an expert involved in the structural design, even if you are building it yourself. If you are planning on building it yourself or with a friend, you may want to enlist the help of an architect or licensed engineer to design the structural support. Different types of structural design and support may apply based on conditions such as height, size and shape of room, roof type, and type of house. All of these situations and more need to be taken into account in the load calculations for the room. If you are dealing with a design professional or a licensed and accredited builder, the structural design and support are some of the things you should ask specifically about. If your builder has the proper experience, background, and training in room design he/she should be able to assist you with a permanent, usable solution that will enhance the value and features of your home.