Save money on renovations by dividing a large space with a wall, in order to form an extra room. The lesson? If you want a bathtub, make sure you have at least 35 square feet to work with for a bathroom addition. No matter if you want to make big or small changes to your home, you need to have a way to pay for them. The bigger is typically better assuming you have enough yard space surrounding the patio. Adding an outdoor living space can be rewarding both personally and financially, so consider these projects that pull double duty. Conversely, you can build a paved or stone patio for about 30 percent less, though its return on investment is harder to calculate.