When adding an addition onto your home there are a couple different directional approaches you will have to consider. You are able to add onto your home horizontally or vertically.
Depending on the type of addition you will have to weigh the pros and cons and evaluate your purpose for the added space.
Building Out
The most common type of home addition occurs on the ground floor of the residence and increases the footprint of the home.
The reason for building out being the most common method is because home additions are almost always kitchen expansions, extending the main living space, or adding a ground floor master suite. Additionally, one-story homes are increasingly becoming more and more popular than two story homes.
How it works: Your contractor will need to excavate the land, install a new foundation, build on the roof and walls, and then open up the existing exterior wall to join the addition.
Advantages: Building out is an easier project to support because it provides the least amount of disturbance to you and family during the process. When building up, the construction crew will be in and out of the house more often than when building out.
Also, if your addition is small enough, you may not even have to pay for foundational work. The contractor can “bump out” a few feet and use floor joists instead to support the addition.
Disadvantages: You will be losing yard space when you build outwards. Not only that, but your town may require you obtain a zoning variance as well.
It is important to check with your town’s Floor-Area-Ratio rating. This rule dictates what proportion of a lot can be built on.
Building Up
Building upwards is not only exclusive to adding on an entire story. You can add on a proportion of space to your second story by installing large dormers in a pitched roof, or you can add living space above a garage or porch.
How it works: Since you are adding an extra load onto your existing foundation, your contractor may need to do a little bit of foundational work to support the addition. This usually involves exposing the foundation to add extra support.
Advantages: You will not lose any yard space and you should not have to worry about pesky zoning rules and regulations.
Disadvantages: Although you may not run into zoning issues, some towns do have a limit on how tall a residential home can be.
If you are adding an entire second story, you will also have to account for loss of space to accommodate a stairwell.