Breathing Straw Bale Wall System

Saatcıoğlu N. Ö., Yaşa E., Tekin İ.

Architectural Eisodes 03, İstanbul, Türkiye, 10 Mayıs - 11 Haziran 2026, ss.95-109, (Tam Metin Bildiri)

  • Yayın Türü: Bildiri / Tam Metin Bildiri
  • Basıldığı Şehir: İstanbul
  • Basıldığı Ülke: Türkiye
  • Sayfa Sayıları: ss.95-109
  • İstanbul Kültür Üniversitesi Adresli: Hayır

Özet

This study presents an innovative, internationally patent-pending passive straw-bale wall and building system that integrates a novel ventilation approach, termed the "breathing wall system".

In many passive house systems and energy-efficient buildings, heating or cooling systems may be unnecessary in moderate climates due to high levels of insulation and optimal building orientation. However, automated ventilation systems with heat recovery are typically indispensable, as such designs emphasize "airtightness," a fundamental principle of 20th-century energy-efficient architecture.

In this context, the term "breathing" does not refer to the conventional 20th-century concept of water vapor permeability in walls but rather to the air permeability of the wall system. The breathing wall system operates through small perforations, approximately one millimeter in radius, located on the façade. These openings facilitate a controlled influx of exterior air into the building interior. The number and dimensions of these perforations are carefully optimized to regulate airflow rate and velocity, thereby maintaining indoor thermal comfort. Additionally, the wall envelope serves as a passive heat recovery system.

Ongoing research involves testing breathing wall systems with various materials, including concrete, timber, and glass, under laboratory conditions and on a small scale. Preliminary findings indicate a significant departure from traditional 20th-century multilayered, air-tight, energy-efficient façades, suggesting a paradigm shift in building envelope design. However, implementing a façade with numerous small perforations presents practical challenges, such as production complexity, susceptibility to dirt accumulation, dust and water infiltration, acoustic vulnerabilities, and condensation risks. These issues must be addressed to facilitate broader adoption.

While conventional building materials have been extensively studied, the potential of straw bales in this context remains largely unexplored. Due to their inherently porous nature, straw bales naturally facilitate airflow. By adjusting the material’s thickness and density, it is possible to regulate both the volume and velocity of air passing through the straw. Furthermore, a patented breathing wall apparatus enables the system to function effectively even on rendered surfaces, mitigating risks such as dirt accumulation, rainwater infiltration, and other operational challenges.

Integrating the breathing wall system with a straw-bale construction approach has the potential to significantly reduce or even eliminate reliance on mechanical HVAC systems. This innovation represents a critical advancement toward achieving "zero-energy buildings" and "carbon neutrality" throughout a structure's operational lifespan.

The SBWNV system introduces a pioneering building envelope concept, offering a novel passive climate-control solution for sustainable architecture.

Keywords: Straw-bale Breathing Wall, Breathing wall, Ventilation, Energy Efficiency in architecture, Zero Energy Building