Written for homeowners, by local experts in Los Gatos

Adding space to your home can feel like a big step—but it’s one of the best ways to increase both comfort and property value. Whether you’re considering a single room, a second floor addition, or an expanded living area, understanding costs is essential before you begin. Experienced room addition contractors near me can provide estimates, but having a general idea of the breakdown helps you plan with confidence.

At EDR Design Build, we guide homeowners through the financial side of home addition services, ensuring your investment is well spent. Here’s what to expect when budgeting for a room addition.

1. Design and Permitting

Before construction begins, you’ll need room addition plans and city permits.

Design fees: $3,000–$8,000 depending on complexity
Permit costs: $1,000–$5,000 depending on local regulations

This stage sets the foundation, ensuring your project is compliant and aligned with your vision.

2. Site Preparation and Foundation

If you’re building an addition on the ground level, expect costs for excavation, grading, and foundation work.

Typical range: $10,000–$30,000
For second floor additions, reinforcement of existing structures may add to the cost.

3. Framing and Structural Work

Framing forms the skeleton of your new space. This step is labor-intensive and varies by size.

Cost estimate: $20,000–$50,000+
Larger projects, like a room extension idea with multiple levels, will be higher.

4. Electrical, Plumbing, and HVAC

Adding a bathroom, laundry, or kitchen to your addition will raise costs due to utilities.

Electrical: $3,000–$10,000
Plumbing: $5,000–$15,000
HVAC: $4,000–$12,000

Working with a skilled general contractor ensures these systems integrate seamlessly.

5. Interior Finishes

This is where your style comes through—flooring, drywall, paint, trim, and fixtures.

Range: $15,000–$40,000+
Upgrades like hardwood, custom cabinetry, or designer finishes can increase costs.

6. Exterior Integration

To make your addition look seamless, siding, roofing, and windows must match the existing home.

Typical cost: $8,000–$25,000
A polished exterior is one of the hallmarks of the best home addition contractors.

Total Estimated Cost

For most Bay Area homeowners, a room addition contractor near me might charge anywhere between $80,000–$250,000+, depending on size, finishes, and complexity. A second floor addition will be on the higher end, while smaller extensions may fall toward the lower range.

The EDR Design Build Advantage

Every project is unique, and costs vary. At EDR Design Build, we provide transparent pricing and full-service construction project management, so there are no surprises along the way. Our goal is to deliver the extra space you need with craftsmanship and care.

Plan Your Room Addition with Confidence

A room addition is a significant investment, but with the right team, it pays off in comfort, functionality, and resale value. Partnering with trusted home addition builders near me ensures your project is completed on time, on budget, and with stunning results.

✅ Ready to get a personalized cost estimate?
Contact EDR Design Build at (650) 888-2107 or [email protected] for a complimentary consultation. Let’s create a room addition that fits your home and your budget.