Airtightness & HVAC Requirements Under the Saudi Building Code: What You Need to Know
Introduction: The Technical Detail Behind the Mandate
Saudi Arabia’s building sector is living through a moment of regulatory maturity. The Saudi Building Code (SBC), which aligns with internationally recognised standards including ASHRAE 90.1, has introduced specific, technical, and testable requirements for building airtightness and HVAC system performance. For project owners, MEP consultants, and contractors, this means that vague compliance claims are no longer sufficient. Data is required — measured, documented, and certified.
This article provides a technical guide to the airtightness and HVAC-related requirements under the SBC, what they demand in practical terms, and how to achieve and demonstrate compliance on Saudi projects of any scale or complexity.
Airtightness: The SBC’s Envelope Performance Requirements
The SBC energy efficiency provisions require buildings to limit uncontrolled air leakage through their envelopes. Air leakage is uncontrolled air movement through cracks, gaps, and unsealed joints in the building fabric — as distinct from designed, ventilated air movement through mechanical systems.
The standard requires that the building envelope be designed and constructed to limit air leakage, and that this limit be verified by testing. The test method used is the standard pressurisation test (blower door test), which measures the building’s air leakage in cubic feet per minute at 75 pascals (CFM75) or, in the metric version more commonly used in KSA, m³/(h·m²) at 50 pascals.
The specific leakage limits in the SBC depend on building type and climate zone. For commercial buildings, the typical benchmark is 0.4 CFM75 per square foot of envelope area. For residential buildings, the target is tighter, typically 3 ACH50 or less for energy-compliant construction. High-performance or net-zero buildings — increasingly common in Saudi mega-developments — target values below 1 ACH50.
Duct Leakage: The HVAC Side of the Equation
Beyond the building envelope, the SBC requires that HVAC duct systems also meet defined maximum leakage rates. In Saudi Arabia’s climate, duct leakage is a particularly serious issue because duct systems frequently run through unconditioned spaces such as ceiling voids, roof spaces, and building service shafts — zones that may be exposed to extreme heat.
When cooled air leaks from ducts into these unconditioned spaces, the energy loss is direct and continuous. Simultaneously, hot air from these spaces can be drawn into return ducts, raising supply temperatures and forcing the AHU to work harder. The SBC’s duct leakage requirements set maximum allowable leakage as a percentage of total system airflow, typically 4% for new commercial construction and 6% for residential systems.
Duct leakage testing is carried out using a duct pressurisation device (duct blaster) connected to the system at the AHU. The test pressurises the sealed duct system and measures total leakage, providing an objective, quantifiable result that can be compared to the SBC threshold.
Commissioning Requirements
The SBC also requires formal commissioning of HVAC systems before occupancy. This goes beyond installation quality checks — it requires that airflows, pressures, and controls are verified against design specifications, and that the system operates as intended under real-world conditions. Specifically, the SBC mandates:
- Testing, adjusting, and balancing (TAB) of air distribution systems to verify design airflows at each terminal unit
- Verification that fan performance matches the design duty, including static pressure and airflow
- Control system commissioning, confirming that thermostats, sensors, and BMS integration function correctly
- Documentation of all commissioning results in a commissioning report submitted with the occupancy permit application
How Aeroseal Arabia Supports Airtightness and HVAC Compliance
Aeroseal Arabia’s service portfolio directly addresses each of these SBC requirements. The company’s certified technicians can carry out blower door testing for building envelope airtightness, duct pressure leakage testing for HVAC systems, and provide full TAB services through its Accutrol Air Flow Solutions division.
Where buildings fail to meet the required thresholds — as frequently happens during initial testing — Aeroseal Arabia provides rectification services. For duct systems, the Aeroseal proprietary duct sealing technology can achieve verified leakage reductions of 90% or more in a single treatment, accessed entirely from the inside without dismantling ductwork. For building envelopes, AeroBarrier sealing delivers guaranteed airtightness performance backed by real-time monitoring and a performance certificate.
Documentation and Regulatory Submission
A critical but often overlooked aspect of SBC compliance is the documentation trail. Regulators do not accept verbal assurances of compliance — they require test reports issued by qualified, certified practitioners. Aeroseal Arabia’s testing teams hold ATTMA (Air Tightness Testing and Measurement Association), RetroTec, and NADCA certifications, ensuring that all test reports are recognised and accepted by Saudi regulatory authorities and international certification bodies including LEED and BREEAM.
Conclusion: Getting Compliance Right from the Start
Meeting the SBC’s airtightness and HVAC requirements is not an afterthought — it is a fundamental design and construction quality commitment. Projects that plan for compliance testing from the early design phase achieve better results, avoid costly remediation, and reach handover faster. Aeroseal Arabia’s team works with consultants and project managers from specification through to certified completion. Contact us to discuss how we can be part of your compliance team from day one.
