IS 3346:2018 is the Indian Standard (BIS) for thermal insulation of buildings - code of practice. This code of practice provides guidelines for the thermal insulation of buildings to ensure energy efficiency and thermal comfort. It covers the selection of insulation materials, calculation of U-values, and condensation control methods for building envelopes.
Provides guidelines for selecting and applying thermal insulation materials in buildings to achieve desired thermal performance.
BIM-relevant code. See the BIM Hub for ISO 19650, IFC, and LOD/LOIN frameworks used alongside it.
| Parameter | IS Value | International | Source |
|---|---|---|---|
| Primary Role | Code of Practice (guidance on 'how-to' install). | Mandatory Energy Code (prescribes 'how-much' insulation is required). | ASHRAE 90.1-2022 |
| Roof U-value (Illustrative) | No mandated value; recommends practices to achieve values set by codes like ECBC (e.g., ~0.25 W/m²K). | Mandatory insulation level, e.g., R-30 (approx. U-value of 0.19 W/m²K) for insulation over deck in Climate Zone 4A. | ASHRAE 90.1-2022 |
| Vapor Control Layer Placement | On the warm side of the insulation. | On the warm side of the insulation to control water vapour movement. | BS 5250:2021 |
| Air Leakage Control | Qualitative guidance on sealing joints and gaps. | Quantitative requirement for a continuous air barrier, often with mandatory whole-building blower door testing. | ASHRAE 90.1-2022 |
| Climate Zone Basis | 5 zones based on temperature and humidity (e.g., Hot-Dry, Warm-Humid, Composite). | 8-9 zones based on Heating and Cooling Degree Days (e.g., Zone 1-Hot to Zone 8-Arctic). | ASHRAE 90.1-2022 |
| Thermal Bridging | Recommends avoiding thermal bridges through continuous insulation. | Requires calculation and accounting for thermal bridges in overall U-value calculations, referencing methods in ISO 10211. | BS 5250:2021 |