🏠 Home Additions vs. ADUs: Which Makes More Sense for You?
🧱 What’s the Difference?
Home Addition: Expands your existing home — adding a bedroom, bathroom, or living area under the same roofline.
ADU (Accessory Dwelling Unit): A separate or semi-separate living unit with its own kitchen, bathroom, and entrance. It can be detached, attached, or converted from an existing structure like a garage.
In short:
👉 Additions increase your personal living space.
👉 ADUs add flexibility and income potential.
💰 Budget Comparison
Project TypeTypical Cost RangeAverage SizeMain Cost DriversHome Addition$200–$400 per sq. ft.400–1,000 sq. ft.Foundation work, roofing, matching finishesGarage or Detached ADU$250–$500 per sq. ft.400–1,200 sq. ft.Utilities, plumbing, kitchen, permits
Home additions are generally less expensive per square foot because they share systems (like HVAC, plumbing, and roofing) with the main home.
ADUs, however, require separate kitchens, bathrooms, and utility connections — raising initial costs but offering potential rental income that pays you back over time.
🏗️ Permitting and Regulations
Home Additions
Require traditional building permits through LADBS or local building departments.
Often need zoning and structural reviews.
Usually inspected as part of the main home’s occupancy.
ADUs
Subject to California’s ADU laws, which streamline approvals.
May qualify for reduced setbacks and parking exemptions.
Require separate electrical and plumbing hookups.
Receive their own Certificate of Occupancy, making them legal rental units.
Pro Tip: ADUs have shorter approval times (often 60 days) thanks to California’s housing laws — making them faster to start in many LA neighborhoods.
🕐 Timeline
PhaseHome AdditionADUDesign & Permits2–4 months2–3 monthsConstruction4–8 months5–7 monthsTotal Timeline~6–12 months~6–9 months
If your priority is speed, ADUs have an edge — especially if you’re using pre-approved “standard plans” from the City of Los Angeles.
💵 Return on Investment (ROI)
Home Additions
Boost resale value by 15–25%, depending on size and design.
Great for families planning to stay long-term.
Adds comfort and livability, but no direct rental income.
ADUs
Increase property value by 20–35% and generate monthly rental income ($1,800–$3,000+ depending on size and location).
Strongest ROI for investors or homeowners looking to offset mortgage costs.
Example:
A 400 sq. ft. ADU costing $160,000 that rents for $2,400/month can pay for itself in 5–6 years, then generate profit indefinitely.
🧩 Space Planning & Design Ideas
For Home Additions
Master suite expansions with walk-in closets and luxury bathrooms.
Open-concept living rooms and kitchens.
Second-story additions for hillside or small-lot homes.
For ADUs
Garage conversions into studio apartments.
Detached backyard units with private patios.
Two-story ADUs with rental upstairs and office downstairs.
Pro Tip: Design your addition or ADU with dual use in mind — family today, rental tomorrow. That flexibility adds long-term value.
🏡 Which One Is Right for You?
GoalBest OptionMore space for familyHome AdditionGenerate passive incomeADUIncrease resale valueEither — depending on layoutFaster constructionADU (with standard plans)Lower upfront costHome Addition
If your goal is comfort and expansion, go with an addition.
If you want income and flexibility, an ADU is the smarter investment.
Conclusion
Whether you’re adding a new bedroom or building a full rental unit, both home additions and ADUs can dramatically improve your property’s value and functionality. The key is working with an experienced general contractor who understands Los Angeles zoning, permits, and building codes.
At Nail & Hammer Construction Corp, we bring five generations of expertise to every project — from design to final inspection. We’ll help you evaluate your property, budget, and goals to choose the right approach for your home.
📞 Call Nail & Hammer Construction Corp at 424-800-3704 to schedule a consultation and explore which option makes the most sense for you.
