What Impacts Home Renovation Cost the Most?

Planning a home renovation can be both exciting and stressful — especially when it comes to understanding what drives the costs. Homeowners often ask, “Why is this renovation so expensive?” or “Where can I save without cutting corners?” To answer these questions, we spoke with Igor, founder of Remodeling Works LLC, a licensed general contractor serving clients across the Greater Seattle area, including Bellevue, Kirkland, Redmond, and Sammamish.

1. Structural Complexity & Mechanical Work

According to Igor, one of the top factors affecting home renovation costs is the complexity of the structural and mechanical work involved.

“If you’re changing the footprint of a room, moving plumbing, HVAC, or electrical systems — especially in bathrooms and kitchens — costs go up quickly. You’re not just paying for labor; you’re paying for expertise, time, and managing liability.”

Modifying load-bearing walls, rerouting ductwork, or reinforcing framing all impact the final price to renovate a house significantly. In many cases, additional structural work must comply with city codes and may require inspections, adding both time and expense.

2. Age & Condition of the Home

The age and condition of the property also play a big role in determining renovation costs.

“We once worked on a 1990s home where everything looked fine inside. But during a bathroom renovation, we found a leaking PVC vent pipe that had caused rot and attracted fire ants. We had to replace studs, headers — it turned into a $40,000 structural remediation job.”

Older homes, especially those with wood framing, may hide issues like rotted framing, poor ventilation, or outdated plumbing — all of which drive up costs unexpectedly.

3. Type of Renovation: Interior vs. Exterior

While both come with challenges, interior home remodeling often involves more technical work. Igor notes that both types depend on the scope:

“For interiors, you’re dealing with layout, design, finishes, plumbing, and electric. Exteriors involve roofing, windows, doors, siding, and landscaping. Each comes with its own pricing structure.”

He emphasized that for anyone working on a split level house remodel, expect additional complexity.

“More levels mean more wiring, more ducting, and tougher access, which often increases labor and material costs, especially when dealing with mechanical systems. Remodeling Works handles all kinds of home renovations, including both interior and exterior house remodeling, so we’re familiar with the full range of challenges that can come up.”

4. Permit Requirements by City

In Washington State, city and county permit requirements vary widely and can directly influence total cost and timeline.

“In cities like Seattle, Bellevue, or Kirkland, permits are a must and often costly. I had a client in Seattle who paid around $3,500 just for an electrical service upgrade permit in 2024.”

Some cities, like Fall City and Woodinville, are known to have more tedious permit processes, which add time and require additional inspections between phases.

5. Material Selections & Finishes

High-end materials and appliances come with higher installation costs — not just purchase prices.

“Installing an $8,000 oven is a lot different from installing a $400 one. The tile can range from $1.50 to over $100 per square foot. And the more expensive the material, the more precise the craftsmanship needs to be.”

Luxury finishes also increase liability, meaning contractors must take extra care, which affects pricing.

6. Hidden Surprises and Budget Buffers

Unexpected problems can drastically shift project budgets. That’s why Igor always advises clients to keep a contingency fund.

“Things come up. Rotten framing, water damage, outdated wiring — you won’t know until you open the walls. Always plan for surprises.”

7. Smart Ways to Save Without Sacrificing Quality

Budget-conscious homeowners can still get value by being strategic. Igor and the Remodeling Works team recently helped a client in Redmond who wanted to prepare a rental property for sale without doing a full gut renovation.

“They didn’t want to spend too much but needed it to look good for market. We focused on painting and simple cosmetic upgrades. No luxury finishes, just clean and functional — and it saved them thousands.”

Another pro tip? Do your research and work with reputable contractors home renovations specialists who are licensed and bonded. Hiring the wrong team can cost far more in the long run.

Home renovation costs vary dramatically based on design complexity, materials, permits, and existing conditions. Whether you’re doing a basic refresh or a full split level house remodel, working with experienced professionals — like the team at Remodeling Works — ensures transparency and quality from start to finish.

From small cosmetic updates to full interior home remodeling, always plan carefully, stay informed, and expect the unexpected.