Can I add a second story to an old home?

You love the character and charm of your older home, but find yourself needing more space. For one reason or another, you don’t have the option of expanding the ground floor level. Instead, you hope to build a second-story addition. But given its age, it seems like this old home already has enough trouble holding itself up, and you wonder if it’s possible to add a second story.

As a Portland-based remodeling firm, Lamont Bros. is no stranger to old homes or second-story additions. Having worked with hundreds of homeowners across the Portland area, we know how to navigate the challenges of adding space to an aging home. Looking for answers on how to add a second story to your old home? You’ve come to the right place.

In this article, we’ll cover everything you need to know before beginning your second-story addition. Once you’re finished reading, you’ll have a more complete understanding of the process and challenges involved in a project like this. With that information, you can decide if a second-story addition is best for you. Here, you can expect to read about:

Why Add a Second Story to an Old Home?

Before getting into the mechanics of how it can be done, it’s important to identify whether or not a second-story addition is the right type of remodel for your needs. These are large-scale, expensive construction projects, so you’ll want to be 100% sure that this is the right move. Here are two important factors to consider:

Do you need more space than you currently have?

The purpose of a home addition is to add living space to a home. There are many reasons why you might choose to build an addition. Perhaps your family has grown since you bought the house. In that case, you might need extra space for the kids as they get older. Or maybe you’ve had a career change that involves working from home and needing office space.

An addition can be used for a new kitchen, additional bedrooms and bathrooms, or a specialty space like a theater room, office, or home gym. In any case, its primary purpose is to increase your home’s square footage. So, to decide if you should add a second story, the first decision is whether your house needs extra space.

Is a second story the best place to add more space?

Once you’re sure that an addition is the type of remodeling project you need, then it’s time to figure out if adding a second story makes the most sense.

Typically, second-story additions are more expensive than adding onto the ground level, but less expensive than adding a basement. So, you should only add a second story to an old home if you’ve ruled out a ground-level addition first. The main reason you would not do a single-level addition would be if space or zoning prevents it.

Adding a second story can be a great way to increase your home’s living space.

Many urban lots like the ones in downtown Portland don’t have enough space to add more to a home’s footprint. Often, the property line sits very close to the side of the home, so you can’t build on the side. Setback laws further prevent you from adding in front or back. Therefore, adding a second story might make sense in this context. However, if you can add to the ground level, it’s usually best to start there.

You’ll also want to consider if the intended use of the space is appropriate for a second level. Bedrooms, bathrooms, and offices are fine for upstairs areas. However, if you plan to add a music room or gym, you should carefully consider how noise from the activities in those rooms may affect other rooms below.

Should I remodel or move

What are the challenges of adding a second story to an old home?

There’s a reason it’s more expensive to add a second story to a home — especially an old home. Second-story additions require a lot of engineering and design work. It’s not as easy as just building a new floor on top of the existing one. You have to make sure that the entire structure below the new construction can support the additional weight.

Can the attic be easily converted into a second story?

Often, the first step in designing a second-story addition is to identify whether or not the attic can be converted to living space without removing the roof. Occasionally, you can add a second story to an old home by building a dormer addition. This increases the usable floor space in the attic and can save a lot of costs in structural engineering and demolition.

In order to convert an attic into legal living space, the ceiling height must be at least 6 feet 8 inches. However, for comfort, most experts recommend a minimum height of 7 1/2 feet. It’s also important to consider the pitch angle of the roof. A low pitch angle means a more gentle sloping roof, which is more difficult to work with when designing an attic conversion. Higher pitch angles offer a more generous head height and make it easier to add dormers.

A dormer addition allows you to convert an attic into living space rather than build an entirely new level.

Is your home’s framing able to support a second story?

The structural framing of your home must be able to support its own weight and any weight above it. For old homes, it can be difficult to add a second story due to the structural condition of the original framing.

Many homes built in the early 20th century did not use the same standards of construction that we do today. As a result, it can be dangerous to add a second story without first inspecting the structural condition of the lower levels. One of the major issues with old homes is a lack of proper sheathing. In construction, sheathing is the boards that are nailed to the framing studs to provide lateral rigidity, which prevents the home from swaying in an earthquake or high winds.

Old homes often lack proper sheathing or, in some cases, any sheathing at all. Modern framing standards also require builders to use specific nailing patterns when attaching the sheathing to the studs. This ensures an even, consistent arrangement of fasteners throughout the home’s exterior. Many old homes were not built using these same standards.

Another classic flaw to consider when remodeling old homes is that the ceiling joists are undersized and can’t support living space. This is especially tricky when adding dormers or building second-story additions. Solving this issue requires either sistering microlams to the existing joists, replacing joists with larger members, or adding support mid-span.

Before beginning a second-story addition, your build team should perform an engineering inspection to identify any potential structural weaknesses in your home’s framing. This will allow for the team to incorporate any necessary changes to the structure into the design so there are no surprise costs to you once the project is underway.

Does your foundation need to be modified or replaced?

Another common point of concern when trying to add a second story to an old home is the foundation. This is especially true in homes built during the early 20th century, as the process of mixing and pouring concrete had not yet been fully refined.

Many old homes do not use spread footings in the foundation. A spread footing is a concrete support structure with a wide base that spreads the weight of the home evenly into the ground it sits on. Without it, homes are more likely to collapse in a seismic event. As a result, you should not build a second story on a home that doesn’t have spread footing.

It’s also possible that, due to its age and the methods used to build it, your foundation may require repair or even replacement. In this case, it may be better to add a basement to your home rather than a second story, since your foundation requires immediate attention, anyway.

Design solutions for adding a second story to an old home

Now that you understand more about the challenges of building a second story on top of an old home, let’s explore a few possible solutions.

By putting your remodel through an engineering review during the early phases of your project, you’ll be able to identify structural issues before they become a threat to your addition. This will also allow you to predict the cost of completing the remodel safely.

Depending on the findings of the engineering process, your designers may recommend some of the following solutions. Keep in mind that these are but a few common practices, but there may be another approach not listed here that works well for your circumstances.

Framing Retrofit

One common solution when adding a second story is to perform a framing retrofit. This process upgrades the existing framing of the home to be able to support the additional weight of a second story.

In a framing retrofit, your build team will add support to the lower level’s framing before constructing the second story. If the sheathing is missing or improperly installed, it’s common to replace it.

The major concern in a framing retrofit is to ensure that the sheathing has the correct number of fasteners attaching it to the studs. In order to do its job of providing lateral support in wind and seismic events, the sheathing must be properly attached. A framing retrofit may also include adding other forms of reinforcement to the structure.

The issue with a framing retrofit is that it requires remodeling the lower level of the home. This often involves removing drywall to expose bare studs, which will add significantly to the cost of the project.

For a second story addition (background) the sheathing on the lower level (front) may need to be reinforced.

Foundation Underpinning

If your foundation lacks the proper footings, it’s possible for areas of the home to sink into the ground. This uneven distribution of weight into the soil can cause serious structural concerns when adding a second story.

Rather than replacing the entire foundation, it is possible to solve the lack of proper footings using a method known as underpinning. In this process, several large helical columns are drilled into the ground beneath the home and attached to the foundation. These columns can be rotated to raise or lower parts of the foundation, meaning the home can be restored to its original level if parts of it have already begun to sink.

Steel Moment Frame

Rather than prepare the rest of the home to support a second story, a steel moment frame uses separate structural support to hold up the addition. A steel moment frame uses steel beams on separate foundation footings to provide structural support to a second-level addition.

This can be an especially effective solution when trying to add a second story to an old home built before 1940, as it requires virtually no structural upgrades to the original home itself. Rather than being one building, it’s more like two buildings nested over top of one another.

However, a steel moment frame does involve extensive structural engineering to ensure that the steel frame can be installed without compromising the integrity of the existing home. There’s also the issue of aesthetics, as the moment frame can become a prominent feature of the home’s exterior. A skilled designer can work to incorporate the frame into the home’s design more naturally, but this can come at the expense of additional labor and materials during construction.

Want to Learn More about Remodeling Your Old Home?

Now that you have a strong understanding of what it takes to add a second story to an old home, continue your research! Check out our article, “What to Know About Remodeling Old Homes in Portland” to learn more about the common challenges of working on historic homes.

Ready to take the next step in your remodeling journey? If so, don’t do it alone! Click the button below to schedule a free design meeting with a member of our professional remodeling team. We’ll help you navigate the process and challenges of turning your current home into your dream home.