Building Envelope Systems

• Features of the Building Envelope and Wall System
• Green Roof
• Green roofs provide additional insulation to the building, reduces the urban heat island effect, and provides a high thermal mass value.
• Thermal mass: 20 Btu/ft*F
• R-value: 2
• 12” Concrete Ext. Walls with 4” of Rigid Insulation
• Although concrete is not considered a good insulator (low R-value), it has a very high thermal mass which means that it can store heat and release it at night when it’s needed; moreover, the typical Portland cement mix can be replaced with a more sustainable alternative such as LC3 or other cementious composites (i.e. ECC). The light color of some ECC mixes helps keep the building cool through a high solar reflectance.
• In order to address concrete’s low thermal resistance, I added 4” of insulation to its interior.
• Overall Performance:
• R-value: 18
• Thermal mass: 22 Btu/ft*F
• Insulated Roof
• R value: 113
• Trombe Wall
• The first-floor building is facing south so it is receiving an abundance of daylighting; I added two concrete trombe walls at the ends of the curtain wall to capture the excess heat.
• Windows, Glazing, and Skylights
• Skylights
• I placed the skylights over areas where daylighting was not sufficient based on my lighting analysis.
• Curtain Walls
• The location of the curtain walls encourage access to the outdoors and limits excess solar radiation.
• Glazing
• The glazing is double glass, 1/4 in thick, low e (0.05). Initially, I designed for 42 VLT but my lighting analysis showed that not enough daylighting was entering the buildings. I removed this from the glazing in order to increase daylighting.
• Shading Features
• 3’ Overhang on roofs
• Shades on windows and curtain walls: 2.5’
• the overhangs decreased my overall insight performance

Baseline Insight Results:

Insight Result with Shading, WWR, and PV surface coverage:

Insight Result including Lighting Efficiency and Daylighting Controls:

Solar Analysis:

Lighting Analysis: