Most homes today are inefficient in design and construction, often wasting space, consuming excessive energy, and requiring frequent maintenance. Many feature detached garages, oversized footprints, and inefficient layouts that drive up costs and make heating, cooling, and upkeep more difficult.
The Courtyard House is a high-performance ADU (Accessory Dwelling Unit) designed for efficiency, resilience, and long-term livability. Designed to fit any 50-foot-wide lot, this compact, single-story home offers a flexible, replicable solution for sustainable housing—built to be durable and resilient while remaining warm and inviting.
Designed to comfortably accommodate a family of four, the Courtyard House maximizes livability while eliminating wasted space. Its single-story design ensures full accessibility, allowing residents to age in place. The floor plan is designed without hallways, eliminating wasted square footage.
Key Features:
• Fits Any 50’ Wide Lot – A versatile footprint that works in various urban and suburban settings.
• Courtyard-Centric Living – A 10’ x 10’ courtyard enhances natural light, ventilation, and privacy while providing a serene outdoor retreat.
• Outdoor Fireplace – Enhances comfort and ambiance without compromising indoor air quality
Unlike conventional homes built with short-term materials, the Courtyard House prioritizes fire resistance, low maintenance, and durability:
• CMU Side Walls – Fireproof barriers provide safety and privacy.
• Hardie Board Siding – A durable, non-combustible exterior that resists fire, pests, and weathering.
• Metal Roof – A standing-seam metal roof offers superior weather protection with minimal upkeep.
•Deep Eaves – Roof overhangs direct rain away from walls, reducing long-term moisture damage.
Most homes rely on insulation placed only within wall cavities, which creates weak points where heat escapes—a phenomenon called thermal bridging. The Courtyard House instead uses the Perfect Wall system, where all four control layers—rain, air, vapor, and thermal—are placed on the exterior. By wrapping the structure in continuous exterior insulation, the building achieves a super-efficient thermal envelope that eliminates thermal bridging and dramatically reduces energy loss.
With this approach, the wood structure is kept entirely inside the conditioned envelope and behind the vapor barrier, where it remains warm and dry. This not only ensures the structure is protected from temperature swings and moisture but also allows the exposed wood to last for centuries. On the interior, the warmth and natural beauty of the exposed wood create a healthy, timeless living environment, free from drafts and hidden mold risks. The airtight assembly also enables superior indoor air quality, since the home can be properly filtered, ventilated, and dehumidified.
Additional benefits include:
ZIP Sheathing System – A fully integrated air and moisture barrier that adds durability and ensures the control layers work as intended.
Airtight Roof-Wall Connection – Instead of traditional rafters penetrating the exterior wall, the roof structure ends at the wall, allowing for a sealed, taped, and continuous enclosure with no air leakage.
Long-Term Resilience – By keeping the structure inside the thermal and vapor control layers, the Courtyard House is designed to stand for generations, with minimal maintenance and maximum comfort.
The Courtyard House redefines compact, sustainable housing by combining efficiency, durability, and timeless design. Optimized for any 50-foot-wide lot, this fire-resistant, single-story home ensures accessibility, privacy, and adaptability for generations. Its scalable, replicable model makes it a future-proof solution for modern, sustainable living.
This project by Derrington Building Studio in Austin, Texas showcases the Perfect Wall system, where insulation is placed on the exterior of the structure, leaving the wood framing beautifully exposed on the interior. Designed and built with simplicity, durability, and beauty in mind, the studio demonstrates how standard lumber and off-the-shelf hardware can be thoughtfully assembled into a structure that is serviceable, sustainable, and built to last centuries. From exposed framing to exterior insulation strategies and clever detailing, it’s a case study in building science and design that proves healthy, long-lasting homes can be both practical and inspiring.
For more information about the Perfect Wall system, visit:
Building Science Corporation – The Perfect Wall