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10 Tips Architects and Builders use to Build a Net-Zero Energy Office Building

The Importance of Net-Zero Energy Buildings (NZEB)

Archi­tects and com­mer­cial con­trac­tors that design and build net-zero ener­gy build­ings (NZEB), lead the way towards a green and sus­tain­able coun­try. NZEBs pro­duce as much ener­gy as they use annu­al­ly.

Com­mer­cial build­ings rep­re­sent 19 per­cent of the ener­gy con­sump­tion in the Unit­ed States. There­fore, imple­ment­ing NZEB meth­ods in com­mer­cial build­ings is cru­cial to com­bat­ing ris­ing ener­gy prices and fos­sil fuel depen­den­cy. Improv­ing ener­gy-effi­cien­cy in com­mer­cial build­ings is also crit­i­cal to reduc­ing car­bon diox­ide emis­sions, a known cause of glob­al warm­ing.

Archi­tects and com­mer­cial con­trac­tors that build and design NZEBs are vital to decreas­ing the nation’s ener­gy con­sump­tion and cre­at­ing a green­er and more sus­tain­able soci­ety.

The Whole-Building System Approach to NZEB

The whole-build­ing sys­tems approach aims to con­struct NZEBs that effi­cient­ly use nat­ur­al resources and lessen waste. The build­ing team (the archi­tects, devel­op­ers, engi­neers, builders, own­ers, and the build­ing’s occu­pants) is involved in all parts of the building’s design and con­struc­tion.

The whole-build­ing sys­tem approach treats an office build­ing as one ener­gy sys­tem in which each part impacts the effi­cien­cy of the entire build­ing. Dur­ing the design phase of a net-zero ener­gy build­ing, the build­ing team works togeth­er to select con­struc­tion mate­ri­als, assem­blies, and sys­tems that min­i­mize ener­gy use and uti­lize renew­able ener­gy sources.

10 Tips for Achieving a Zero-Net Energy Office Building

1. A zero-net-ener­gy office build­ing must have a robust ther­mal build­ing enve­lope with a con­tin­u­ous air and mois­ture bar­ri­er. The ASHRAE 90.1 and the 2015 IECC, in fact, require con­tin­u­ous insu­la­tion (CI) in many com­mer­cial struc­tures.

Wrap­ping a build­ing with a lay­er of CI, along with an air and mois­ture bar­ri­er increas­es the effec­tive­ness of the build­ing enve­lope and ensures a com­fort­able indoor envi­ron­ment. An excel­lent prod­uct that pro­vides a high per­form­ing build­ing enve­lope is the Bau­tex Wall Sys­tem.

The Bau­tex Wall Sys­tem cre­ates ener­gy-effi­cient exte­ri­or walls that con­tribute towards a zero-net-ener­gy office build­ing.

2. Site ori­en­ta­tion (pas­sive solar design) of an NZEB is crit­i­cal for tak­ing advan­tage of the sun’s ener­gy. Specif­i­cal­ly, in the North­ern Hemi­sphere build­ings should be ori­ent­ed north-south. The north-south ori­en­ta­tion min­i­mizes direct sun­light dur­ing the sum­mer (which reduces cool­ing demands) while max­i­miz­ing sun­light dur­ing the win­ter (which low­ers heat­ing demands).

3. The win­dows of a ZNEB should make the most of nat­ur­al light and con­trol heat gains and loss­es. For exam­ple, win­dows that auto­mat­i­cal­ly dark­en when direct sun­light hits them (elec­trochromic and ther­mochromic) help con­trol bright­ness, glare, and heat. Fur­ther­more, shades and lou­vers on south­ern fac­ing win­dows can assist in block­ing out the heat in the sum­mer and let­ting warmth in the win­ter.

4. A cool roof of an NZEB pro­tects against solar heat gain and keeps the build­ing cool. Denser mate­ri­als like tiles, slate, or clay or mate­ri­als that are reflec­tive or have light col­ored pig­ments that reflect the sun­light are good cool roof prod­ucts. Cool roofs improve indoor com­fort of a com­mer­cial build­ing and reduce ener­gy bills.

5. The heat­ing and cool­ing sys­tems of com­mer­cial build­ings account for 34 per­cent of a building’s ener­gy use. The design of an ener­gy-effi­cient com­mer­cial build­ing should include high-effi­cien­cy heat­ing and cool­ing sys­tems that use less ener­gy.

For exam­ple, the most effi­cient HVAC sys­tem is 95 per­cent effi­cient; mean­ing 5 per­cent of the ener­gy pro­duced is lost. It is imper­a­tive that HVAC pro­fes­sion­als install the sys­tems in accor­dance with ENER­GY STAR build­ings. Improp­er instal­la­tion of an HVAC can reduce the effi­cien­cy of a sys­tem by up to 30 per­cent.

6. Pro­vid­ing prop­er ven­ti­la­tion of an NZEB with an ener­gy recov­ery ven­ti­la­tion sys­tem is essen­tial because the air-tight­ness of an NZEB may trap pol­lu­tants (like radon, formalde­hyde, and volatile organ­ic com­pounds). An ener­gy recov­ery ven­ti­la­tion sys­tem man­ages ven­ti­la­tion and lessens ener­gy loss by trans­fer­ring ener­gy from con­di­tioned air going out to fresh incom­ing air.

7. A com­mer­cial building’s office and com­put­er equip­ment account for 6 per­cent of a building’s ener­gy. The design of an NZEB must include ENER­GY STAR®-labeled office equip­ment and elec­tron­ics.

8. Light­ing con­tributes up to 10 per­cent of a com­mer­cial building’s annu­al elec­tric­i­ty costs and is a cru­cial design con­sid­er­a­tion of an NZEB. Con­trols such as timers, pho­to­cells that turn lights off when not in use, and dim­mers can save ener­gy and mon­ey.

Exam­ples of ener­gy-effi­cient light­ing include light-emit­ting diodes (LEDs), com­pact flu­o­res­cent lamps (CFLs), and halo­gen incan­des­cent.

9. The design of an NZEB should aim to cre­ate as much ener­gy as it uses by installing renew­able ener­gy sys­tems, like solar pho­to­volta­ic (PV) pan­els, wind sys­tem, small hybrid” elec­tric sys­tem, or micro­hy­dropow­er.

10. Con­nect­ing net-zero ener­gy build­ings to a tra­di­tion­al ener­gy source (nat­ur­al gas, elec­tric, etc.) is advis­able since the renew­able ener­gy gen­er­at­ed can­not always meet the building’s ener­gy loads. How­ev­er, when the renew­able ener­gy exceeds the build­ing ener­gy require­ments, the sur­plus ener­gy can be trans­mit­ted back to the util­i­ty grid, which helps the build­ing achieve the ener­gy bal­ance need­ed for an NZEB.

The Future of Net-Zero Energy Federal Buildings

In 2015, Exec­u­tive Order (EO) 13693 intro­duced new Fed­er­al sus­tain­abil­i­ty require­ments and expand­ed upon require­ments estab­lished by EO 13514, EO 13423, the Ener­gy Pol­i­cy Act of 2005 (EPAct 2005), and the Ener­gy Inde­pen­dence and Secu­ri­ty Act (EISA) of 2007.

Archi­tects and builders inter­est­ed in fed­er­al con­tracts should take note of Exec­u­tive Order (EO) 13693. Exec­u­tive Order 13693 requires fed­er­al build­ings greater than 5,000 square feet to begin plan­ning for net-zero build­ings by FY 2020 or lat­er. Also, fed­er­al build­ings greater than 5,000 square feet must achieve net-zero ener­gy (and water or waste net-zero, where fea­si­ble) by FY 2030.

The Whole-Building System Approach to Constructing an NZEB

Key to archi­tects and builders achiev­ing a net-zero ener­gy office build­ing is apply­ing the whole-build­ing sys­tems approach. The whole build­ing approach ensures that all mem­bers of build­ing team work togeth­er to min­i­mize ener­gy use and uti­lizes renew­able ener­gy sources; with the ulti­mate goal of achiev­ing a net-zero ener­gy office build­ing.

Con­struct­ing NZEBs is essen­tial towards decreas­ing ener­gy use, depen­den­cy on fos­sil fuels, and car­bon diox­ide emis­sions. Please vis­it Bau­tex™ Wall Sys­tem for more tips on achiev­ing net-zero ener­gy office build­ings.

Adverse impacts of glob­al warm­ing include an increase in wild­fires, ris­ing sea lev­els, more acidic oceans, and more fre­quent and severe weath­er events.