Renovating a home is a major expense and it can really disrupt your life. Depending on where you live, getting the proper building permit can also be a major headache. If you would like a little extra space to create a home office, artists studio, hobby room, wood shop, honey house, kid play house or home gym, there are a number of companies that sell kits that allow you to build these structure relatively inexpensively compared to traditional renovation and without many of the hassles.
In many urban and suburban areas, traditional construction requires local government review of plans, permits, inspections etc. Navigating the process requires some experience and probably is best left in the hands of a professional contractor or architect. However, most communities will allow you to put a "shed" on your property without permits and inspections. And this is where the fun begins because a number of companies now sell building kits that qualify as sheds under local zoning rules, but are really beautiful small spaces that look like traditional housing additions. Here's the scoop....
While the rules will vary from community to community, most communities don't require a permit or inspection if the structure is less than 120 square feet. In my community in Northern California the rules also stipulate that you not run electricity or water to your shed. (Some communities put restrictions on the number of "habitable" buildings that can be put on a particular piece of land.) What all this really means is that these sheds aren't really practical as long-term living spaces for guests or elderly relatives but they are great for pretty much every other use you can think of. You probably could get away with letting house guests stay in one of these sheds for a few days if furnish it with a sleeper sofa.
In my area the weather is so temperate that a structure like this could be used 2 or 3 seasons of the year without heat. However, I suspect that by adding a kerosene space heater you could make it a habitable space even in the dead of Winter without violating any zoning rules.
If you search the Internet, you can find a number of companies selling shed kits in a variety of styles from traditional to quite modern (see photos below). Price are generally $70-$100 per square foot based on the ones I've seen ($8-12,000 for a typical small space). That's pretty cheap when you consider that new construction costs over $200 per square foot in many suburban communities and renovation is generally even more expensive.
If adding a structure to your garden is of interest to you, check out some of these companies: