Sometimes a prospective client will ask, "What's the cost per square foot for building a home addition?"

    When most people ask this question, they simply want to get some idea in advance of what their addition is going to cost. Once we have a sense of your needs, the cost picture can come into clearer focus. In terms of cost per square foot, it is important to understand a fundamental difference between custom home renovation and new home building.

    Refer to our helpful resource page to gain a better understanding of how to budget for a home addition project

    Custom renovation appears to be much more expensive (per square foot) than the new home. Why? Because in a new build, the cost of the most expensive rooms in the house (kitchens and baths) gets spread over double or triple the square footage. Most Washington, DC home additions must be built to fit on fairly small lots. Since most home additions involve less than 1,000 square feet of new space, the big ticket features inflate the cost per square foot of a typical home addition. 


    It's really about scale. Producing many square feet of product gives the appearance of low (per square foot) unit cost. Custom renovation, particularly additions (for master suite, modern kitchen and family room) pack a lot of quality into a relatively small area, adding tremendous value into the home. So, trying to put a value based on size (cost per square foot) is a deeply flawed basis for comparison.

    How do i understand the value of a home addition?

    It is helpful to think of value per square foot for home additions rather than cost per square foot. By way of example, here is a first-floor layout for an addition we designed for a Washington, DC area home.


    An addition doubles the size of this house, providing an opportunity to reconfigure the entire first floor plan. The value of the new rooms is extremely high. This design plan was conceived to enhance the unique characteristics of the existing house and to free it of its former limitations. Everything about it is custom. Compare the size of the old kitchen (left) with the new design (right). Also, you can see that we expanded the dining room (right) when we eliminated the old kitchen. The old living room (left) was reconfigured to create a foyer and den (parlor).

    What are the benefits of adding onto a house?


    One thing we’ve learned about Washington, DC homeowners over the years is that all of them want more room!

    We hear the frustrations. Your home doesn’t have enough space to comfortably accommodate all the people, pets, and possessions. It may be that you need more space and that an addition is the solution. It could also be that you need better organized space, customized to your needs.

    Our designers and architects specialize in space planning — making better use of the space you already have. If we can solve your problems without building an addition, it will have a significant impact on budget requirements.


    Don’t overlook the factor of comfort in a home addition project. Once space is added and issues that led to the addition in the first place are addressed, you are going to enjoy living in the space much more. Instead of feeling cramped or that space is being underutilized, you and your family will fit in the renovated, reconfigured, and beautified space.

    resale value

    Solving space utilization and flow problems in your home will also make it more attractive to buyers. That is not to say you can always expect to get your money back out of a renovation at resale. But with a home where renovation has taken place, buyers will see the value in, and will be more motivated to make an offer on the home. 

    factors that may lower home addition costs

    As part of your home renovation planning, the design team will help you understand all of your options with or without investing in a home addition. The designers will:

    1. Identify problem areas and fixes such as wall removals or relocation of doors/windows
    2. Recommend ways to make a room better suited to its purpose
    3. Repurpose under-used rooms
    4. Add comfort features that make a room more inviting
    5. Rework the floor plan for better flow and reclaiming space for storage or a powder room

    Ultimately, you may or may not need us to design a home addition. Reconfiguring the interior of your home may be enough to meet your needs. If you do decide a home addition is the right choice, you and the designers have taken a close look at the challenges you are facing, and the most practical, cost-efficient ways of tackling those challenges.


    tips for keeping home addition costs reasonable

    Understanding your budget and sticking to it are crucial. You need to work with a renovation company that will manage the budget as well. We need to agree on a renovation budget in advance so that we can set expectations. It’s important to have a frank discussion about the costs of the various steps in the process. We can answer all your questions and help you understand not only the costs, but how your money can best be invested to increase the value of your home.

    Early budgeting discussions will help you understand where your money should go — which components of the plan justify more dollars and which might be minimized. A little prioritization can go a long way. Although homeowners often dislike many things about their house, we’ve found that addressing the biggest issues first can quickly reduce the size of your “must have” list and bring your project scope in line with your budget.

    Getting the most out of your washington, dc addition

    It’s hard to talk about numbers without a specific set of designs in front of us. But when we develop a concept for your home addition together, we can discuss and define the cost of that addition in specific terms.

    As your home renovation partner, we’re not going to tell you what to do: It’s your home. We want you to love it.

    Our job is to help you understand your options and make the best possible decisions for your home investment and for your family. If you feel ready for a serious conversation about taking that next big step, make an appointment to meet with one of our design-build specialists.

    To learn more about the home addition design-build process, download our eBook titled "How Gilday Renovations Integrated Team Delivers the Home of Your Dreams" to get an in-depth understanding. If you are considering a home renovation, please feel free to schedule a home renovation discovery session with Gilday today.

    home addition

    Leave a comment