1. Interior construction Harvard Graduate School of Design

2. Technical criteria for interior construction 1. Safety regulations governing material behavior in fire/natural disaster 2. Durability relative to impact loads (humans, furnishings, etc) 3. Ease of maintenance 4. Tactile environment 5. Acoustic environment (reflective/absorptive surfaces) * Weathering and waterproofing concerns less important

3. Fire safety regulations: building codes classify buildings by 1. Use or occupancy: assembly, business, educational, factory, hazardous, institutional, mercantile, residential,storage, utility 2. Construction type (types 1 thru 5): combustible, noncombustible, and combination These classifications together determine: allowable building footprint height + number of stories applicable fire safety requirements

4. Construction types: based on fire ratings of structural and enclosure materials Types 1 + 2 All noncombustible construction Types 3 + 4 Noncombustible exterior walls + combustible interior structure Type 5 Combustible structure

5. Construction types: based on fire ratings of structural and enclosure materials

6. Interior finish materials and assemblies are given fire resistance rating. Class I (ASTM* 0 - 25) least combustible Class II (ASTM 26 - 75) Class III (ASTM 76 - 200) most restricted use Ratings based on material composition, thickness, conditions of substrate and attachment. *American Society for Testing and Materials

7. Special areas of regulation: 1.Fire stairs and means of egress = very strict in most occupancies 2. Vertical shafts, duct penetrations 3. High-ceiling spaces 4. Doors and their hardware 5. Glazed areas * Many traditional flooring materials (wood, vinyl tile, terrazzo) exempt from restrictions except in cases of unusual danger.

8. Maintenance issues: 1. Porosity of finish surface = acceptance of dirt, grease, dust 2. Exposure to water 3. Exposure to human touch/ interaction

9. Acoustical dilemma: Hard, non-porous surfaces are easy to maintain but can create reverberant, harsh acoustic environments. Quiet spaces generally require combination of hard and soft finishes.