Eunoia Builders Inc.
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    • Home
    • Portfolio
    • Our Story
    • Get in Touch
    • Service Areas
      • Sunnyvale CA
      • Palo Alto, CA
      • Los Gatos CA
      • Los Altos CA
      • Cupertino CA
Eunoia Builders Inc.
  • Home
  • Portfolio
  • Our Story
  • Get in Touch
  • Service Areas
    • Sunnyvale CA
    • Palo Alto, CA
    • Los Gatos CA
    • Los Altos CA
    • Cupertino CA

Home Addition Construction in Cupertino, CA

Looking to expand your living space without moving out of the neighborhood you love? Our home addition services in Cupertino, CA, are designed to give you the extra room you need without sacrificing comfort, style, or structural integrity. Whether you're building up, out, or converting underutilized space, we help homeowners add square footage while maintaining seamless architectural flow.


From single-room expansions to large-scale second-story builds, our team is trusted throughout Cupertino for reliable craftsmanship, transparent pricing, and compliance with local building regulations.

Expand Your Living Space Your Way

Cupertino is one of the most desirable places to live in the Bay Area, and expanding your home can increase both its value and its long-term livability. We help you create purposeful spaces tailored to your lifestyle needs.

Custom Room Additions

Custom Room Additions

Custom Room Additions

Need a home office, nursery, guest room, or family room? We design and build fully integrated room additions that align with your existing structure, rooflines, and aesthetics. No “boxy” add-ons, just cohesive, comfortable spaces that feel like they’ve always been there.

Garage Conversions

Custom Room Additions

Custom Room Additions

Turn your unused garage into livable square footage with a professional conversion. Whether it becomes an in-law suite, a game room, or a rentable studio, our garage conversions meet all Cupertino zoning and energy compliance codes while maximizing property use.

Second Story Additions

Second Story Additions

Second Story Additions

Out of yard space but need more room? A second-story addition is a smart way to double your space vertically. Our engineers assess your existing foundation and framing, then design structurally sound second levels that fit your home’s character and boost your property’s value.

ADUs and Guest Units

Second Story Additions

Second Story Additions

As housing demand grows, Cupertino homeowners are increasingly adding Accessory Dwelling Units (ADUs). We offer complete ADU design and build services from backyard cottages to over-garage units tailored for multigenerational living or additional rental income.

Our Step-by-Step Process

We know that expanding your home is a big decision. That’s why we’ve refined a step-by-step process that ensures clear communication, city compliance, and top-quality results.


1. Initial Consultation

We begin with a free in-home consultation where we evaluate your space, listen to your goals, and discuss options for layout, budget, and timelines.


2. Design & Engineering

Our design-build team creates architectural plans that blend style and structure. We ensure all plans comply with Cupertino building codes, structural safety requirements, and energy standards.


3. Permitting & Planning

Permitting in Cupertino can be complex. We handle all submissions, revisions, and approvals so you never have to navigate the bureaucracy alone.


4. Construction & Management

With a dedicated project manager overseeing daily progress, our licensed crew works efficiently and cleanly. We coordinate trades, handle inspections, and keep you informed every step of the way.


5. Final Walkthrough

Once your addition is complete, we conduct a final walkthrough to ensure every detail meets your expectations and our standards. We also offer warranty support for lasting peace of mind.

Why Cupertino Homeowners Choose Us

As a locally experienced contractor serving Cupertino and the South Bay, we understand what makes a successful addition project:


✅ Familiarity with Cupertino’s zoning and setback requirements


✅ In-house design and structural engineering team


✅ Attention to architectural consistency


✅ Clean work sites and respectful crews


✅ Transparent timelines and cost estimates


✅ Fully licensed, insured, and code-compliant builds


We believe in building trust as well as square footage.

Serving All Cupertino Neighborhoods

Whether you’re in Monta Vista, Rancho Rinconada, or near De Anza College, our team has worked in nearly every corner of Cupertino. We understand neighborhood aesthetics, HOA preferences, and what adds true market value in this competitive area.

Ready to Expand? Let’s Talk.

Adding space to your home is more than a construction project it’s an investment in comfort, functionality, and future equity. If you're ready to create more space in your Cupertino home, let’s schedule a consultation to get started.


Your vision. Our craftsmanship. Let’s build something great together right here in Cupertino.

CALL US

Copyright © 2025 Eunoia Builders Inc. - All Rights Reserved.


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