Your home should work for your life today — not just when you bought it. Whether your family is growing, your lifestyle has changed, or you simply want more room to enjoy, a well-designed home addition can transform your space without the hassle of moving. At Mares & Dow Construction & Skylights, Inc., we’re not just adding square footage — we’re creating functional, beautiful spaces that feel like they’ve always belonged.
For over 40 years, our team has built custom home additions in Walnut Creek and the East Bay, combining skilled craftsmanship, meticulous planning, and a deep understanding of local building codes and architectural styles. From historic homes near Parkmead to modern residences in Northgate, we know how to design and construct additions that blend seamlessly with your property while enhancing its value and comfort.
We handle every step — from initial concept and permit approvals to construction and finishing touches — so you can enjoy a stress-free experience and a result that exceeds expectations. With our long-standing reputation for reliability, quality, and clear communication, you can trust that your investment is in expert hands.
Expanding Your Space With a Home Addition Contractor. Serving San Francisco and the East Bay Since 1983. Contact us now!
If your current layout feels cramped, your storage is maxed out, or you’ve been dreaming about a bigger kitchen, primary suite, or family gathering space, it’s time to explore your options with a trusted local contractor. Our Walnut Creek home addition experts understand that every home — and every homeowner — has unique needs. That’s why we take a tailored approach, designing additions that fit your vision, budget, and lifestyle.
We specialize in a wide range of addition projects, including:
Our process begins with an in-depth consultation, where we learn about your goals, assess your property, and share design ideas. From there, we create a clear, realistic plan and guide you through each step until your new space is ready to enjoy.
With Mares & Dow, you’re not just getting a construction crew — you’re partnering with a team that treats your project as if it were our own home. We bring decades of experience in Walnut Creek construction, precise workmanship, and a dedication to keeping your project on schedule and within budget.
Choosing the right home addition contractor can make the difference between a stressful experience and a smooth, rewarding transformation. Walnut Creek homeowners turn to Mares & Dow Construction & Skylights, Inc. because we deliver on our promises — and have been doing so since 1983.
Here’s why we’re the preferred choice:
We’re more than builders — we’re your partners in creating a home addition you’ll love for years to come.
Every homeowner has unique needs, and we pride ourselves on offering a full spectrum of home addition services to match. Whether you’re aiming to expand, reconfigure, or modernize your home, we have the tools, expertise, and creativity to make it happen.
Our Walnut Creek home addition services include:
Our team has completed home additions across Walnut Creek’s diverse neighborhoods, adapting designs to fit each area’s unique character and property needs.
We also serve areas near Broadway Plaza, Heather Farm Park, Shell Ridge Open Space, and Lesher Center for the Arts.
Adding on to your home is exciting, but it can also reveal hidden challenges—especially in a city like Walnut Creek, where homes range from historic ranch-style properties to modern hillside residences. Our team has decades of experience identifying and solving the unique problems that can arise during the home addition process, ensuring your project is completed smoothly, safely, and beautifully.
Here are some of the most common issues we resolve for homeowners in Walnut Creek:
Many homeowners worry about whether their new addition will “flow” with the original structure. We ensure your addition is properly tied into your home’s existing foundation, framing, and roofing, so it looks seamless and functions as one solid structure—not an afterthought.
Walnut Creek’s varying soil conditions—especially in hillside neighborhoods like Rudgear Estates—can cause settling or shifting if not addressed. We handle soil testing, grading, and reinforced foundation work to give your addition long-term stability.
We transform tight, compartmentalized spaces into open, functional layouts by removing non-load-bearing walls, reconfiguring traffic flow, and creating a cohesive design between old and new spaces.
Mismatched rooflines are one of the biggest giveaways that a home has been added onto. We carefully match pitches, materials, and architectural details so your new space blends seamlessly with your existing home.
Older homes often have systems that can’t handle the demands of an expanded floor plan. We upgrade wiring, panels, and plumbing to meet modern building codes and household needs.
We use modern insulation, energy-efficient windows, and HVAC solutions to ensure your addition maintains consistent comfort year-round—while keeping your utility bills in check.
Mares & Dow Construction & Skylights has been part of the Walnut Creek community for decades. With over 40 years of Bay Area construction experience, we understand local architecture, zoning regulations, and the high expectations of Walnut Creek homeowners.
Our reputation for quality, dependability, and personalized service means that many of our projects come from referrals and repeat clients. We’re proud to be trusted by families across the city to transform their homes into spaces that truly fit their lives.
If you start noticing problems with your home addition—whether it’s cracks in the walls, uneven flooring, sticking doors, or a roofline that no longer looks straight—it’s important to act quickly. Small issues can escalate into costly repairs if ignored, and in some cases, they may even affect your home’s structural integrity or safety.
The first step is to document the problem. Take photos, note when you first noticed it, and pay attention to whether it’s getting worse over time. Next, avoid any quick DIY fixes that could mask the issue instead of solving it—covering up a crack, for example, won’t address the underlying structural cause.
Contact a professional home addition contractor in Walnut Creek who understands local building codes, climate factors, and soil conditions. Our team at Mares & Dow Construction & Skylights Inc. will inspect your addition from top to bottom, identifying whether the problem is cosmetic or structural. We also assess related systems—like electrical, plumbing, and HVAC—to ensure the entire addition is performing as it should.
Many home addition issues in Walnut Creek are caused by factors such as improper tie-ins to the original structure, inadequate foundation work, poor-quality materials, or insufficient waterproofing. Our expertise allows us to not only diagnose and repair the problem but also prevent it from recurring by reinforcing critical structural connections, improving moisture protection, and updating systems to meet current standards.
The sooner you address an issue, the easier and more cost-effective it is to fix. Waiting could mean more extensive damage, higher repair bills, and even code violations if the addition no longer meets safety requirements.
Tip: If you’ve recently purchased a home in Walnut Creek with an existing addition, schedule a post-purchase inspection to catch any hidden issues early.
You’ve worked too hard on your home to risk its value or comfort. If you see signs of trouble with your home addition, contact us today for a thorough inspection and expert repairs—we’ll make sure your addition remains safe, beautiful, and functional for years to come.
The timeline for a home addition in Walnut Creek depends on the project’s size, complexity, and permitting process. Smaller additions like a bump-out or enclosed patio may take 6–10 weeks, while larger two-story additions or full wing expansions can take 4–6 months. Factors like weather, supply chain delays, and design revisions can also affect the schedule. At Mares & Dow Construction & Skylights, Inc., we provide a realistic timeline during the planning phase so you can plan with confidence.
Yes. Most home additions in Walnut Creek require building permits from the City of Walnut Creek Building Division to ensure compliance with local building codes, safety regulations, and zoning requirements. This includes structural changes, plumbing and electrical work, and any changes to the building footprint. Our team handles the permitting process for you—saving you time, reducing stress, and ensuring a smoother build.
We specialize in a wide range of home addition services, including:
Whether you need a simple room addition or a multi-story expansion, we design and build to blend seamlessly with your existing home.
Home addition costs vary based on the square footage, finishes, complexity, and structural requirements. In Walnut Creek, prices typically start around $350–$500 per square foot for quality construction. Factors like custom features, high-end materials, and intricate designs can raise the cost. We provide a detailed estimate upfront so you understand exactly where your investment is going.
Absolutely. We specialize in seamless design integration so your new addition looks like it has always been part of your home. From matching rooflines and siding to replicating trim, windows, and finishes, our design-build approach ensures both structural and aesthetic harmony.
Yes. Quality additions that enhance square footage, functionality, and curb appeal often boost resale value—especially in high-demand Walnut Creek neighborhoods. A thoughtfully designed addition can improve both livability and marketability, giving you a strong return on investment.
Yes. As a full-service design-build contractor, we manage everything from concept to completion—design planning, architectural drawings, engineering, permitting, construction, and finishing touches. This streamlined approach ensures better communication, fewer delays, and a final product that exceeds expectations.
Preparation can include clearing out rooms adjacent to the work site, securing valuable items, and arranging an alternative living space if needed for major renovations. We work with you to minimize disruption, set up dust barriers, and maintain a safe, clean work environment throughout the project.
Yes. Walnut Creek has zoning regulations that govern property line setbacks, building height limits, and lot coverage ratios. Homes in hillside areas may also face special grading or slope stability requirements. We research and verify all zoning regulations before we start, ensuring your addition meets legal and safety standards.
It’s easy—just reach out to our team to schedule a consultation. We’ll discuss your vision, budget, and timeline, then provide design ideas, material recommendations, and a detailed proposal. Your dream home expansion starts with one call.
📞 Contact us today to begin planning your Walnut Creek home addition.
As a trusted home addition contractor in Walnut Creek, CA, we’ve built a strong reputation for delivering seamless, high-quality expansions that blend perfectly with your existing home. Whether you’re looking to add a second story, extend your kitchen, create a new master suite, or build a sun-filled family room, our team is here to make it happen—on time and within budget.
We know Walnut Creek’s neighborhoods and building requirements inside and out, which means we can help you navigate permits, zoning, and HOA guidelines with ease. From Northgate and Rudgear Estates to Saranap, Rossmoor, and beyond, we’ve completed projects that enhance curb appeal, boost property value, and improve everyday living.
Our service area includes:
No matter where you live in the Walnut Creek area, we bring the same level of dedication, skill, and personalized service to every home addition project.
Our Walnut Creek home addition experts work closely with you from the first design consultation to the final walkthrough, ensuring every detail aligns with your vision, budget, and lifestyle. We combine innovative design, durable materials, and expert craftsmanship to create additions that look and feel like they’ve always been part of your home.
Whether your project is large or small, we’re committed to making the process as smooth and stress-free as possible. That means clear timelines, transparent pricing, and excellent communication every step of the way.
You deserve a home that fits your life. Let’s build it together.
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