High Performing Buildings - Fall 2010 - (Page 48)

BuIldIng enVeloPe Roof Type intensive green roof (average 10 in. depth). A drainage layer/filter fabric/ water retention fabric with root barrier is on top of a 60-mil loose-laid waterproofing membrane. next is a 80-mil sprayapplied, asphaltic-type waterproofing membrane installed over a 5.25 in. reinforced concrete deck. Also, the underside of the roof has open-cell insulation with spray-applied fire protection coatings. overall r-value r-66 reflectivity medium Walls Type Portland cement plaster exterior facing is installed over a moisture barrier system on osB rigid sheathing. The sheathing covers 6 in. steel studs that have spray-applied, closed-cell insulation at a minimum 4 in. depth, and gypsum board interior facing. overall r-value r-26 glazing percentage 36% Foundation slab edge insulation r-value r-5 (estimated) Windows u-value 0.33 solar Heat gain Coefficient (sHgC) 0.15 Visual Transmittance 7% uV Transmittance 0%; aluminum curtain wall/window wall systems are thermal break type location latitude 29° 36’ 43”n orientation Primary axis: east to west Aerophoto.com e n e R g y at a g l a n C e (PRedICted) energy use intensity (site) 24 kBtu/ft2 electricity 24 kBtu/ft2 Annual source energy 81 kBtu/ft2 Annual energy Cost index (eCi) $0.72/ft2 · yr savings vs. standard 90.1-2004 design Building 38.1% energY sTAr rating 95 Annual Co2 savings 143 metric tons note: Predictions are based on the statement of energy design intent, which was generated by energY sTAr’s Target finder. This difference is significantly less than a typical structure. Looking beyond the energy impacts of a vegetative roof, the designers have reduced storm water runoff, improved water quality, reduced the heat island effect, reduced sound reflection, created wildlife habitat, and improved the aesthetics of the roof. Additionally, the life of the roofing membrane (a typical lifespan in the Houston climate is 10–20 years) has been extended to potentially 50 years because of the protection from UV rays, extreme temperature swings and harmful pollution. Also, according to one study,1 green roofs increase property values. This aerial view from the southwest illustrates the vegetative roof design, the building’s east-west axis and minimally intrusive LED parking lot lights. to providing detention for storm events on site. The cistern is a network of 48 in. diameter piping situated below the parking areas. It holds a two-year event (the heaviest rainfall that is predicted to occur once every two years, or 4.5 in. in 24 hours), but the discharge rate is equal to or less than the original undeveloped discharge of the site. The cistern system also can supplement the building’s graywater system, if necessary. Building envelope The building envelope is faced on the exterior with portland cement plaster and has vapor barriers and 100% water blown, spray-on, closed-cell foam insulation within a 6 in. frame. All of this provides an assembly with a minimum R-value of 26. In addition, it has the ability Cistern system The Gulf Freeway building irrigation system has no connection to city potable water. An underground cistern holds approximately 320,000 gallons of water in addition fa l l 2 0 1 0 48 HigH Performing Buildings http://www.Aerophoto.com

Table of Contents for the Digital Edition of High Performing Buildings - Fall 2010

High Performing Buildings - Fall 2010
Table of Contents
IDeAs Z2 Design Facility
Lighting Design Alliance
Manassas Park Elementary School and Prekindergarten
FC Gulf Freeway Office Building
Capturing Condensate
National Australian Built Environment Rating System
Tyson Living Learning Center

High Performing Buildings - Fall 2010