Cost to Add a Second Story: Factors, Tips, and What to Expect

Adding a second story to your home is a significant investment, offering increased space and potentially higher property value. But before you begin, it’s essential to understand the cost to add a second story and the full scope of expenses involved. This guide covers both visible and hidden costs, planning tips, and what to expect, helping you make the best decision for your home.

Table Of Content

The cost to add a second story varies widely, influenced by factors such as your home’s structure, type of square footage added (e.g., a bedroom vs. a kitchen), and local building codes. Stylistic preferences can also affect the final cost.

Over the past five years, the cost of second-story additions has ranged from $60,000 all the way up to $1,000,000. For example, adding a 200 sq.ft game room above an existing bedroom will cost significantly less than a similarly sized second floor addition of a master bedroom (with a bathroom included).

Let’s explore what you can do in order to better understand your expected costs and what they are comprised of.

*To learn how different spaces can affect price on a project, read our bathroom remodel cost breakdown.

The three largest cost drivers are framing and foundation requirements. Here’s what to consider:

Framing costs account for 20%-25% of any second floor addition project (i.e a $500,000 renovation budget should take into consideration about $75,000-$100,000 only for the framing part). Framing a second story requires structural planning to support the load and blend with the existing structure, which may involve strengthening wall supports. Discuss how your design is going to affect the costs with your architect or builder, since it will be a key factor in correctly budgeting for your project. Features like wall height, large openings for cantina doors, second story deck, thickness of walls, roof pitch and style: are only some aspects that can influence your cost and ultimately the budget for the entire project.

Foundation reinforcement typically accounts for 10%-15% of the budget, or roughly $50,000-$65,000 for a $500,000 project. When planning a second story, discuss potential foundation impacts with your builder or architect to avoid costly surprises later on.

Finish materials, another major cost, can represent 10%-35% of the total budget. Larger projects often allocate more for finishes since there are more rooms to complete.

*Pro Tip: discussing your long term goals with your designer/builder on the use of the home and functionality of the space will assist in selecting the right material at an affordable price.

In addition to construction and materials, several hidden costs come with a second-story addition. Here are key areas to budget for:

Permit fees can be a relatively small amount ($4,000-$5,000) of the overall costs associated with adding a second story or in some cases a lot higher ($20,000-$30,000). Whether you are working with a design & build construction firm or architectural firm, they should be able to give you a rough estimation where on that spectrum you may end up.

Learn more about YNK Construction’s experience with local permitting on our comprehensive permitting page (will be released soon).

Additional Resources:

• City of San Diego fee schedule
• County of San Diego fee schedule

Adding another story may require upgrading your electrical, plumbing, and HVAC systems to support the additional load. Because you are working with a house that already has existing systems in place, you are more limited to how things can installed on the new floor-plan. Rerouting utilities or updating systems to code can add significant costs. That is why a site visit (sometimes even multiple ones) is required prior to making a quote to identify these key issues.

Contact us to schedule a consultation and discuss your second floor addition and build a comprehensive quote for your project.

If your home’s foundation or structure isn’t up to current standards, reinforcements may be necessary to support the second story, adding to expenses. These expenses are not accounted for when getting a price per square foot, and that is why working with an experienced builder to understand your specific situation before accepting a bid is important.

Depending how invasive the second floor addition will be, You may need to temporarily relocate, especially if the entire roof is removed, adding unexpected housing costs. Explore short-term rental options to plan for temporary housing during construction.

*That is a good time to call in on that favor from your brother in law (can easily save $10,000-$20,000 on housing expenses).

Building up might seem ideal when land is limited, but it’s not always the most budget-friendly choice. Ground-level expansions often have a lower cost per square foot but can come with added expenses for earthwork, grading, and demolition. They also take up more yard space, which could impact your home’s overall value.

We recommend beginning by exploring your building options without focusing solely on price. First, narrow down to the two options that best address your needs. Pricing each option will then help you make a well-informed decision based on the project’s goals, affordability, and overall value.

Adding a second story expands living space without sacrificing yard area and can increase your home’s value. However, it’s a significant investment that requires careful planning, realistic budgeting, and consideration of long-term needs. By understanding the complete cost breakdown and consulting YNK Construction, you can make an informed decision on whether a second story is right for your home. Contact us for a custom quote to see how we can help make your vision a reality.