Converting a garage into a spare room can be a cost effective way to add useable living space to your home, and can be a wise move for a number of reasons, but it can also become a big problem if you do not convert the garage legally. Zoning laws vary by different cities. However, all areas require homeowners to have a building permit if they want to convert their garage into an extended residence. Unfortunately, without the appropriate permits, local officials could indefinitely dampen your dreams of a new room. In order sail smoothly ahead with your garage conversion plans, you’ll need to show that the building structure is up to code and also be required to submit a set of plans for future renovations and construction. If you do decide to convert a garage into living areas consider the cost benefit of the new room.  Garage conversions can go either way in that they can either be beneficial and bring a profitable return or raise the property value, or they can become complete nightmares that actually compromise your homes value. The rule of thumb is to look around. If the majority of the properties in the neighborhood have garages, a conversion could have a negative impact on the value, or make the house less desirable. Check out the market first to see if garage conversions are considered desirable features in that market or neighborhood. Involving professionals in garage conversions will help you avoid major problems down the line. Although the DIY route is tempting, you should consider consulting with an architect or designer to help plan the garage conversion project. The added benefit of a general contractor and designer is that one can plan on the aesthetic, the other on the functionality, and the two can work together to oversee every step.  Often even if you hire one or the other, they'll likely already have a team lined up they've usually worked with in the past. Hiring a licensed and trained contractor, plumber and electrician can also prevent serious mistakes. The fact is you never know what can go wrong.  Leaks, floods, fires, failed structures are all a likely possibility in such situation.  However, if you have a professional working on your renovation, then chances are they're insured to fix the mistake.  It'll also hold likely that you're home insurance company will pay for the damage if and only if you had hired a licensed professional. Using a licensed plumber is also important if your home has a septic system. Your county or state may require you to upgrade to a larger system if you add bedrooms, since your change indicates that additional people will probably be living there.