5 Common Mistakes Homeowners Make When Hiring House Addition Contractors
March 25, 2025 •Brian Hogan

Home additions offer a unique advantage over standard remodels: the ability to build out an entirely new space. This means you can design an addition that perfectly suits your individual needs and reflects your personal style.
Whether your vision is to create a new family room, build a master suite with a spa-like bathroom, or develop any other idea requiring extra space, a home addition can be the perfect project to make it a reality.
However, while home additions offer tremendous potential, they can go awry if not properly planned and managed. In this post, I’ll review five of the most common mistakes that homeowners make when hiring a contractor for a home addition. I’ll also discuss how to avoid these pitfalls when planning a new addition to your house.
Mistake #1: Hiring an Under-Qualified Contractor
A home addition is more complex than most remodels. As a result, you need a contractor with the right skills and experience to perform the work to the highest standards.
Problems frequently arise from hiring an under-qualified contractor. Notice that I didn’t say “unqualified,” although that would be a problem, too. But what I’ve seen happen most often is that homeowners hire someone like a handyman or a contractor who specializes in simple, facelift remodeling projects.
These contractors may be great at that kind of work, but they are underqualified to manage the more complicated design and construction process required for a successful home addition.
To avoid this mistake, you should never skip doing your due diligence before hiring a contractor. At the most basic level, that means checking that they’re licensed, bonded, and insured. But it also means looking for any concerning reviews or consumer complaints.
Additionally, you should ask to see examples of home additions in their portfolio and look for clear indications of high-quality work experience. We always recommend asking for client references from past remodels and following up with them, especially if their project has some elements that overlap with yours.
Mistake #2: Choosing a Contractor On Price Alone
Everyone loves a deal, so I understand why many people's eyes go straight to the bottom line when they get a proposal for a home addition. But focusing on price alone when choosing a contractor frequently leads to headaches -- and higher costs -- down the road.
Instead of thinking about price, I encourage people to think about value. In this way, it's not just about what it costs but what you get in return. The honest truth is that top-tier remodelers aren't always the most expensive, but they're virtually never the ones offering a bargain-basement bid.
Why does this matter? First and foremost, a new addition is a major project, and you want the final result to meet your expectations. Second, mistakes in the design phase or during construction can have huge ramifications. Those errors can be extremely expensive to go back and fix. That can make your project take longer and go way over budget, making it costly to have placed so much emphasis on price at the outset.
Mistake #3: Not Getting a Fixed Bid
A major mistake when hiring a contractor for a home addition is failing to get a fixed-price bid. Many people only get bids for time and materials contracts, which creates more risk for homeowners.
Before getting into the details, let's clarify the two main types of bids or contracts.
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Time and materials: You pay for the labor and materials necessary to finish the project plus a markup for the general contractor. The initial proposal is a line-by-line estimate of how much work will be needed, but it's not binding. If costs go up, you're required to pay for overages.
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Fixed-price: The proposal is a lump-sum budget that includes all the work required to finish the home addition. If more labor is required than the contractor anticipated, that cost comes out of their bottom line, not your pocket.
Home additions can have a lot of unknowns, and with a time and materials contract, the risk of cost overruns falls on your shoulders. In contrast, a home addition contractor who offers a fixed bid takes that risk on themselves and is incentivized to come up with a much more accurate estimate upfront. In this way, a fixed bid prevents you from being surprised by huge cost overruns after construction begins.
In the end, some people may still prefer a time and materials contract, but it's a mistake not to get at least one fixed-price bid during the proposal process.
Mistake #4: Not Considering a Design-Build Firm
During a home or room addition, the design is critical to a smoother permitting process and the overall success of the project. Nevertheless, many people make the mistake of looking to hire a home addition general contractor without considering the benefits of hiring a full-service design-build remodeling firm.
As the name indicates, a design-build firm manages the full lifecycle of a remodel. They offer design services from an in-house designer who can draw on the expertise of the firm's internal construction team. In the initial phases, the designer works closely with you to create a detailed home addition design and construction plan. Once that's ready, the project can seamlessly transition to permitting and construction.
This approach eliminates the need to have a separate designer and general contractor, an arrangement that too often leads to miscommunication about exactly how the project should unfold. For major remodels like home additions, there's a huge advantage to having the entire project managed under one roof. It leads to more convenience and cost control for homeowners along with a higher-quality final product.
Mistake #5: Not Exploring the Option of Redesigning Your Existing Home
Sometimes, the biggest mistake in a home addition is assuming from the get-go that an addition is the only option.
Additions are not the only way to make it feel like you're walking into a brand-new house. In some cases, better utilization of your existing home's footprint provides a better return on investment than adding extra space.
Home additions are expensive and disruptive. As such, reworking your current layout may be an excellent and more budget-friendly option for all types of renovations, from a kitchen remodel to building out a new master suite or revamped family room.
Before deciding that you need a home addition, it's worth taking the time to sit down with a talented designer to discuss your ideas and explore a redesign or remodel. Even if you still opt for an addition in the end, going through the process of considering a redesign can help refine your vision and optimize your project plan.
Making Your Home Remodeling or Home Addition a Reality
I've already gone into detail about why it's so important to hire a high-quality firm or contractor if you're looking to create a new space in your house. There's no substitute for great home addition design and skilled, experienced construction management.
Hogan Design and Construction has been serving our neighbors in the Chicagoland area and in southern Wisconsin for over 25 years. As a design-build firm, we manage custom and complex remodels from start to finish, offering our clients seamless service, attentive communication, and a dedication to bringing their home addition ideas to life.
If you're thinking about building an addition to your house, we invite you to get in touch with us about our firm and how we can help. On our website, you can request an appointment, and you can also see our portfolio and learn more about our team.