HECS Blog — HVAC Testing, Energy Certification, and Building Performance

Air-tightness thresholds tightened, climate-zone mapping reversed — here’s what changed for CZ 4A and 5A projects.

Section 45L remains the federal government’s most useful credit for energy-efficient multifamily construction — but the filing window is narrowing.

What code officials actually flag — and how builders in Louisville, Lexington, and Indianapolis should plan their blower door sequence.

Field-level implications for Kentucky residential HVAC testing under the AIM Act transition.

Code, credits, and certification pathways that move closings and protect margin in Kentucky’s 2026 build cycle.

Air-sealing the duct system is one test, two pressure regimes, and a code citation that builders routinely misread.

What code officials actually verify at final inspection — and where Kentucky CZ4A projects fail.

The Problem: Roof Performance Depends on a Complete Load Path

The federal baseline is moving. Kentucky builders need to know what shifts on site.

IBHS updates, Kentucky code reality, and where HECS plugs in on the verifier side.