CEM: Codes and Standards

This domain tests your command of the standards that define minimum energy performance, ventilation, comfort, auditing, commissioning, and energy management. Questions frequently ask which standard applies to a building type, which compliance path is being used, and whether a design meets a prescriptive limit.

Core documents

• ASHRAE 90.1 sets minimum energy requirements for commercial and high-rise residential buildings; ASHRAE 90.2 covers low-rise residential.
• The IECC is a model energy code adopted by jurisdictions; its commercial provisions are coordinated with 90.1, but the adopted edition and amendments govern.
• ASHRAE 62.1 addresses ventilation for acceptable indoor air quality; ASHRAE 55 addresses thermal comfort; ASHRAE 100 addresses energy efficiency in existing buildings.
• ASHRAE 105 covers commissioning; ASHRAE 211 covers commercial building energy auditing; ASHRAE 189.1 is a high-performance green building standard.
• ISO 50001 defines an energy management system; ISO 50002 covers energy audits; ISO 50006 covers baselines and energy performance indicators; ISO 50015 covers measurement and verification.
• NFPA 70 (NEC) governs electrical installations; NFPA 855 addresses stationary energy storage.

Compliance paths

Prescriptive compliance limits individual components, such as lighting power density (LPD), envelope U-factors, and equipment efficiency. Trade-off paths allow poorer performance in one area if offset elsewhere. Performance compliance uses whole-building energy modeling under rules such as 90.1 Appendix G. A standard is not law until adopted by the authority having jurisdiction.

Worked example

An office project has 10,000 ft² and the adopted code lists an LPD allowance of 0.90 W/ft². Allowable connected lighting power = 10,000 × 0.90 = 9,000 W. The design has 60 luminaires at 150 W input each, or 9,000 W, plus 20 task lights at 15 W each, or 300 W, for a total of 9,300 W. The design exceeds the allowance by 300 W. The reasoning: use input wattage including drivers and ballasts, and include all permanently installed lighting in the calculation. The designer must remove at least 300 W, specify lower-wattage luminaires, or use an allowed control credit if the adopted code permits it.

Traps that cost marks

• Using lamp wattage instead of luminaire input wattage.
• Mixing the space-by-space and building-area LPD methods.
• Applying 90.1 without checking whether the local code adopted it or an amended IECC.
• Confusing ventilation requirements in 62.1 with energy-code requirements.
• Treating a standard as mandatory when it is only a reference or voluntary framework.