What Is Sustainable Design?
This article is part of the PAS Design Series. For the full version of our integrated design approach, see:
👉 Sustainable Design in Real Projects – Full Guide
What Is Sustainable Design? A Smarter Way to Build From the Ground Up
Sustainable design is one of the most overused phrases in architecture—and one of the least understood. It’s often mistaken for installing solar panels, checking off energy compliance, or specifying “eco-friendly” products. But that’s not how we approach it.
At PAS Architects, sustainable design is not a feature—it’s the foundation of how we design homes that are livable, resilient, and cost-effective over time. It’s about system thinking: how site, climate, structure, and space planning work together to reduce waste, adapt to change, and perform long after the first year of occupancy.
This is Part 1 of our PAS Design Series, where we break down how Passive | Adaptive | Sustainable design actually works in real Southern California projects. If you want the complete overview in one place, you can also read the full guide here:
👉 Sustainable Design in Real Projects
Our Approach: Sustainable Design as System Thinking
Sustainable design at PAS Architects isn’t about checking boxes or chasing buzzwords—it’s about how everything connects. Our integrated approach blends three core strategies that support each other and elevate performance across every project type.
- Passive strategies reduce reliance on mechanical systems by leveraging sun angles, wind patterns, and material performance. For example, in a backyard ADU, we used cross ventilation and deep overhangs to eliminate the need for air conditioning in most seasons, keeping the unit efficient and comfortable year-round.
- Adaptive architecture builds flexibility into the layout and structure, allowing spaces to evolve with changing life stages or occupancy types. A garage conversion we designed in Downey included pre-routed plumbing for a second bath and a removable partition—giving the owner the option to convert from home office to rental unit without future construction.
- Sustainable detailing ensures long-term durability and resource efficiency through smart material choices and low-maintenance assemblies. On a hillside home in Palos Verdes, we used fiber cement siding with a ventilated rain screen to reduce thermal load, resist wildfire exposure, and extend the lifespan of the envelope.
These aren’t isolated tactics. At PAS Architects, they work together from the earliest design phase. Whether we’re designing a 600 sq ft ADU or a full custom residence, the PAS framework makes every square foot perform smarter—technically, environmentally, and financially.
Why It Matters in Southern California
Southern California isn’t just a design-forward region—it’s a high-stakes one. Our climate, codes, and site constraints demand more than just aesthetic solutions. Sustainable design here is about meeting real challenges head-on—with architectural strategies that hold up under pressure.
- Heat and wildfire conditions are intensifying, requiring homes to be more resilient by default. In a recent WUI-zone ADU, we specified non-combustible siding, ember-proof venting, and radiant-barrier roof decking—all built into a clean, modern design without compromising budget or aesthetics.
- Energy codes are tightening each cycle, with Title 24 requiring higher performance from even the smallest structures. For a remodel in La Palma, we helped the homeowner exceed code by 20% using improved insulation, strategic window placement, and solar prewiring—without relying on high-cost systems.
- Housing needs are shifting rapidly, with more demand for multigenerational flexibility, rental income, and remote work zones. A client in Lakewood asked for an ADU that could later become a teen suite or long-term rental. We built in dual entries, flexible room sizing, and sound attenuation—all within a 580 sq ft layout.
- Lots are often constrained—narrow, sloped, or boxed in by setbacks, requiring creative design to meet zoning and performance goals. On a compact urban lot in Signal Hill, we used a rotated L-shaped layout to meet side yard requirements, preserve solar exposure, and create usable outdoor space—all while staying under height restrictions.
In Southern California, sustainable design isn’t a luxury—it’s survival strategy. The best-performing projects aren’t the biggest or flashiest. They’re the ones designed to adapt, to last, and to use every inch—and every watt—wisely.
Early Design Decisions That Drive Long-Term Value
Most of a building’s performance is locked in during the first 10% of the design process. These strategies may seem small—but they unlock compounding value over time.
- Orienting an ADU for cross ventilation: In a Lakewood backyard ADU, we placed windows to align with afternoon breezes and added clerestory glazing for vertical airflow. The result: passive cooling on most days of the year, with minimal HVAC use.
- Sizing roof overhangs for solar control: For a single-story home in Rossmoor, we designed south-facing eaves to shade high summer sun while allowing winter sunlight to warm the interior slab—reducing both cooling and heating needs without mechanical input.
- Framing for future solar integration: A Whittier garage conversion included pre-wired roof conduits and an optimized pitch for south-facing solar. Two years later, the owner installed panels in a single day with no roof work or electrical rerouting needed.
- Using durable siding to reduce maintenance: In a two-story remodel in Long Beach, we used fiber cement over a rain screen assembly to allow walls to dry naturally—extending finish life, improving comfort, and reducing cooling loads from solar exposure.
- Designing layouts that adapt to future use: We created a 1-bedroom ADU in La Palma with a flexible open living space, mirrored outlets, and removable millwork. Later, it can become a 2-bedroom rental or aging-in-place unit—without any structural changes.
Each of these choices reflects a bigger idea: build once, build smart, and design for what comes next.
Project Example: Sustainable ADU Design
A 580 sq ft detached ADU in La Mirada was designed with long-term performance in mind. We used:
- Cross-ventilation aligned with wind patterns
- South-facing overhangs for passive shading
- Recycled-content siding with zero-VOC finish
- A solar-ready roof with built-in conduit
- A flexible layout to serve as office, rental, or guest space
The client now uses the space with minimal energy input and no retrofitting—and the unit’s market value exceeds comparable builds due to its long-term performance.
Project Example: Sustainable Custom Home
In a custom home outside Palos Verdes Estates, sustainability shaped every decision. We implemented:
- Passive cooling via clerestory windows and stack ventilation
- Deep eaves and landscape buffers to control solar exposure
- A roof structure framed for future PV and storage battery installation
- A rainscreen cladding system for thermal efficiency and moisture protection
- Zoned insulation and radiant barrier sheathing for envelope performance
The home operates 30–40% more efficiently than a standard code-compliant build—and is ready to evolve with its occupants as needs change.
What’s Next: Passive Design Strategies That Actually Work
In Part 2 of this series, we’ll dive into the real mechanics of passive design strategies—what works, what doesn’t, and how to get the biggest benefit for the least cost in a California climate.
You’ll learn how to design for light, air, heat, and comfort—without spending more or adding complexity.
Or skip ahead to the full guide here:
👉 Sustainable Design in Real Projects
To explore more of the design thinking, construction progress, and project execution behind our work, visit the PAS Architects Facebook page or view project videos on our YouTube channel. PAS Architects is a licensed architecture firm based in Cerritos, California, specializing in Passive, Adaptive, and Sustainable design. We serve clients across Southern California — including Los Angeles County, Orange County, and Riverside County — with a service-driven approach rooted in technical clarity and long-term impact
