Rental Income
Turn unused space into a long-term or short-term rental. An ADU adds an independent income stream without purchasing a separate investment property.
ADU Construction in Pasadena & Los Angeles
Add rental income, multigenerational housing, or additional living space to your property — designed, permitted, and built start to finish by one team.
Why Homeowners & Investors Are Building ADUs
An ADU — Accessory Dwelling Unit — is a secondary living space built on your existing property. Whether detached, attached, or converted from an existing structure, ADUs are one of the most practical ways to increase your property's value and utility without relocating.
Multigenerational Living
Keep family close with a private, self-contained living space on your property. Separate entrance, full amenities, complete privacy.
Property Value
A permitted, professionally built ADU increases your home's appraised value and marketability — a tangible return on your investment.
Built for Homeowners and Investors
An ADU — Accessory Dwelling Unit — is a secondary living space built on your existing property. Whether detached, attached, or converted from an existing structure, ADUs are one of the most practical ways to increase your property's value and utility without relocating.
Homeowners
You have the property. An ADU puts it to work. Whether you're housing family, generating rental income, or simply adding livable square footage — ATP handles every phase from design through final inspection so you don't have to coordinate multiple contractors.
Investors & Developers
Adding an ADU to a residential property is one of the most cost-effective ways to increase rental yield and appraised value. ATP manages architecture, permitting, and construction as a coordinated process — keeping your project on schedule and on budget whether you're local or investing remotely from out of state.
Everything Your ADU Project Requires — Managed by One Team
Most homeowners don't realize how many moving parts an ADU project involves. ATP coordinates every phase so nothing falls through the cracks.
Architecture & Design
Floor plans, elevations, site analysis, and permit-ready documentation tailored to your lot and local zoning requirements.
Structural Engineering
Engineered plans, foundation design, and soils coordination aligned with city requirements before submission.
Permitting & Expediting
Full plan check submission, zoning review, city coordination, and correction management until your permits are approved.
Site & Civil Work
Grading, earth mobilization, caissons, and retaining walls coordinated as part of the construction scope where required.
Construction & Framing
Foundation, framing, and structural systems built by ATP's construction team with all trades — electrical, plumbing, and mechanical — coordinated under ATP.
Finish Work
Insulation, drywall, interior finishes, and fire sprinklers where required — carried through to final inspection.
Every Type of ADU, Built to Code
Every property is different. ATP builds all ADU types and works with your specific lot conditions, zoning requirements, and goals to determine the best fit.
Detached ADU
A fully independent structure built separately from the main home. Detached ADUs offer the most privacy and flexibility — ideal for rental income, multigenerational living, or a dedicated guest space. Requires its own foundation, utilities, and permitted entry.
Attached ADU
An addition connected to the existing home, sharing at least one wall. Attached ADUs maximize livable square footage on smaller lots while maintaining a separate entrance and full independent amenities.
Garage Conversion
An existing attached or detached garage converted into a fully permitted living space. One of the most cost-effective ADU options — the structure already exists, reducing site work and foundation requirements significantly.
Junior ADU (JADU)
A smaller unit created within the existing footprint of the primary home — typically up to 500 square feet. As of January 2026, owner-occupancy is no longer required for JADUs with a private bathroom, making them a more flexible option for homeowners looking to generate rental income with minimal structural disruption. Note: JADUs cannot be used as short-term rentals under 30 days.
How an ADU Project Works With ATP
ADU projects involve more steps than most people expect. Here's how ATP moves your project from first conversation to finished build — clearly and efficiently.
1. Consultation
We review your property conditions, lot size, zoning requirements, and goals to determine ADU feasibility and the best unit type for your site. No commitment required at this stage.
2. Design & Architecture
ATP develops permit-ready architectural plans — floor plans, elevations, site layout, and all documentation required for city submission. Structural engineering and soils coordination are completed during this phase.
3. Permitting & Plan Check
ATP submits your plans to the city, manages zoning review, responds to plan check corrections, and coordinates with Building & Safety through full permit approval. We handle this entirely — you don't chase the city.
4. Pre-Construction
With permits approved, ATP finalizes scheduling, procures materials, coordinates trades, and prepares your site for mobilization.
5. Construction
Your ADU is built with active project management, milestone updates, and full trade coordination — foundation through finish.
6. Final Inspection & Completion
ATP coordinates all final inspections, signs off with the city, and walks you through the completed unit before handover.
ADU Construction Serving Pasadena & Greater Los Angeles
ATP builds ADUs throughout Pasadena and the surrounding communities of Los Angeles. Our familiarity with local zoning ordinances, city permitting processes, and regional building requirements allows us to navigate approvals efficiently across every jurisdiction we serve.
- Pasadena
- Altadena
- San Marino
- Arcadia
- Sierra Madre
- Glendale
- La Cañada Flintridge
- Los Angeles County
Don't see your city listed? Contact us — we serve clients throughout Los Angeles and can confirm coverage for your specific location.
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Frequently Asked Questions About ADU Construction
Do I need to move out during ADU construction?
In most cases, no. ADU construction — particularly detached units and garage conversions — typically does not require you to vacate your primary residence. Your ATP project manager will walk you through any site-specific considerations during consultation.
Do I need my own architect?
No. ATP provides coordinated architectural and engineering services in-house. You work with one team from concept through permit approval — no need to source a separate architect or engineer.
Can I rent out my ADU?
Yes. ADUs can be used as long-term rentals. Note that Junior ADUs cannot be used as short-term rentals under 30 days per California law. Your ATP team can walk you through rental compliance during consultation.
Do I need owner-occupancy to build a JADU?
As of January 2026, owner-occupancy is no longer required for JADUs that include a private bathroom. If your JADU shares a bathroom with the primary residence, occupancy requirements may still apply. ATP will review your specific situation during consultation.
How does ATP handle permitting?
ATP manages the full permitting process — plan submission, zoning review, plan check corrections, and city coordination — through full permit approval. You are not responsible for chasing the city or managing submissions.
Can ATP build an ADU if I already have architectural plans?
Yes. If you have completed plans, ATP can review them for constructability and code compliance before beginning the construction process. If revisions are needed, we communicate directly with your architect prior to submission or build.
Does ATP build all ADU types?
Yes. ATP builds detached ADUs, attached ADUs, garage conversions — both attached and detached — and Junior ADUs. The right unit type for your property is determined during your initial consultation based on lot conditions, zoning, and your goals.
Do you work with out-of-state investors?
Yes. ATP works with investors and property owners who are not local to the Greater Los Angeles area. We provide structured project updates and manage the full scope locally on your behalf.
How do I know if ATP is the right fit for my project?
ATP takes every project seriously — and that goes both ways. Just as clients evaluate contractors, we take time during consultation to ensure your project is the right fit for our team. That process protects both parties and sets the foundation for a successful build.
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Ready to Add an ADU to Your Property?
Schedule a consultation to review your property conditions, ADU options, and next steps toward design and permitting.
ATP serves homeowners and investors throughout Pasadena, Altadena, and Los Angeles.