The Ultimate Guide to Adding a Second Floor to Your Home: Expert Tips and Advice

Is your starter home turning into your long-term or forever home? It’s obvious you need more square footage, and maybe a second-story addition seems like an option, but is it even possible?

If your home has enough structural support at the foundation level, a second floor can be a fantastic decision for your current home. A second-story home addition will create a better living environment for you and your family and a more desirable outcome for your home’s value when it comes to resale.

This article will walk you through everything you need to know about adding a 2nd story to your home.

Why Do I Need a Second Floor?

To consider taking this big step means there are significant limitations in your current floor plan. It’s essential first to capture why you need a larger home. As yourself:

• What are your most significant pain points?
• Do you need additional bedrooms, a home office, a playroom, or an extra bathroom (or two)?
• Do you need all of the above?

A first-floor addition might seem like the most obvious solution, but lot lines on many suburban properties are limited and will impact whether or not you can achieve a first-floor home addition. Towns have zoning restrictions that only allow a certain percentage of the land to be developed. Building up (adding a second-story addition) instead of out does not impact your lot lines or the percentage of water-permeable surface that must remain on your lot. You’ll need to contact your municipality or work with a design-build firm with a solid track record of helping homeowners navigate local building codes.

Adding a new second story is perfect for adding the space you need for bedrooms and bathrooms, relocating a laundry room, or adding a bonus space to house a playroom or office.. If you already have a two-story home, you may have space to extend the second story over a garage for a partial second-story addition. If you have a single-story home, you can add as much of a second floor as you need on top of the first. 

How Difficult is it to Add a Second Story?

As the saying goes, if it were easy, everyone would do it. But with the right design-build firm, it can be a very positive experience, from the initial interview to layout and interior design choices to the time the remodeling project is complete. Here are the top considerations for adding a 2nd story to your home:

Foundation

The first question to answer: Can my foundation support a full second-story addition? Here are a few rules of thumb:

• If the current home’s foundation and ground floor are structurally sound enough to support the weight of the second floor, it can work.
• If you have a full basement, you can most likely add a second-story
• If you have a crawl space, you most likely can add a second story
• If your home is built on a slab, you cannot add a second story on the slab foundation.

Your design-build team can help you determine if your foundation is in good shape to support a second-story addition and what options are available to you.

There are also square footage requirements that must be adhered to, such as you can only build X % of square footage on a specific lot size. These restrictions vary by town. It’s essential to work with an experienced design-build general contractor who will thoroughly investigate to determine if your home is structurally sound and strong enough to support a new second story. A structural engineer may need to be brought in to ensure the house can support the desired new space.

Second-Story Home Addition: How to Successfully Blend Old and New

Keep in mind that you are embarking on what will amount to a whole home renovation. Access from the first-floor living space to the second floor-will need to be accounted for. Where will your stairs go? How will your landing and hallway function best to maximize the room spaces in the second story?

You will also want to take the opportunity to update both internal and external materials on the existing house so there is not a jarring difference between the existing home and the new construction upstairs. 

How should you redesign the first floor so it makes sense in relation to the new spaces on the second floor?

Here are a few things to consider:  

• A 2nd story addition should look like it has always been there. The interior and exterior should look seamless. A high-quality design-build firm will make this a high priority.
  
  
• If you are using only part of the first floor's footprint for the second-floor addition, you may consider a new roof so that the existing roof material accurately matches the roof of the new addition. If your roof is relatively new, this may not be an issue, but if it needs to be replaced soon anyway, you may as well do it all simultaneously.
  
  
• Where will the stairs be located? You’ll need to account for a landing on the first and second floors. There are what is referred to as “rise and run” requirements. Rise is the height of each step, and the run is the overall length of the stairs. This will have to be calculated and designed to meet code requirements. 
  
  
• You will likely be redesigning and repurposing the first-floor space. This might mean opening up walls or redesigning the first-floor areas as a home office or craft room.
  
  
• Consider aging-in-place. You might want to keep a bedroom or even a full primary suite on the first floor and either continue to use it as a bedroom or use it as flex space (like a home office) until you decide to use it again as a bedroom as you age.
  
  
• Now that you have a new addition, you will have more space on the first floor. Do you want to upgrade and expand your kitchen and dining area? This is an excellent time to consider remodeling your first floor to an open-concept floor plan. The bedrooms that used to be on the first floor can now help you create more living and entertaining space.
  
  
• Creating indoor/outdoor living and entertaining spaces is a priority for many homeowners. This could mean installing a slider or double French doors to maximize the space you will gain by building up.
  
  
• The number and configuration of bathrooms are likely to change. Chances are, you won’t need two full baths on the first floor. Here’s where you’ll decide if one can be converted into a mudroom or first-floor laundry since the space already includes plumbing.
  
  
• Ensure you keep first-floor storage by maintaining existing closets or reconfiguring to allow for a more functional first floor. Consider including an enlarged pantry and/or adding a mudroom.
  
  
• A second-story addition will likely come with the need for an upgrade to your HVAC system to control the temperature of the new add-on.
  
  
• Adding additional bathrooms to your second floor will likely result in a need for upgraded water service- an increase in the size of the pipe from the street to your home to support the additional water needs of your home. 

Is Adding a Second Floor Worth It?

Yes! Increasing the amount and size of the bedrooms and bathrooms will provide a competitive edge in terms of resale value compared to the original home’s square footage and features of a single-floor home.

A second-story addition home improvement project will enhance your overall quality of life and offer more room for everyone in the household to have their own space. For families with children, the additional space makes it more probable that they will invite friends over more frequently. By carefully considering the layout and design of the expanded areas, you can entertain guests more comfortably and fully appreciate your home.

Second-story additions can be an excellent idea, but much planning must be done upfront to create a space that meets your needs and is cohesive from top to bottom. Experience is critical, so be sure to work with a design-build company with expertise in adding second-floor additions.

Learn how to successfully plan a 2nd story home addition project by downloading the eBook “Home Addition Design 101: A Comprehensive Guide to Planning a Family-Friendly Addition.”