Trends in Passive Design in Texas Homes


As the res­i­den­tial new build mar­ket con­tin­ues to move towards green and ener­gy effi­cient options, Net Zero con­struc­tion is pick­ing up speed. Net Zero hous­es — those that gen­er­ate as much ener­gy as they con­sume — are becom­ing increas­ing­ly com­mon. There are even entire Net Zero sub­di­vi­sions being built in Texas cities these days.

When build­ing a Net Zero house, it’s impor­tant to ensure it is designed to be as ener­gy effi­cient as pos­si­ble from the very begin­ning before adding renew­able ener­gy sys­tems. By reduc­ing a home­’s ener­gy require­ments, Net Zero is eas­i­er to achieve.

That’s where pas­sive design can come into play.

Using smart build­ing mate­ri­als to man­age heat fluc­tu­a­tions through­out the day, pas­sive design har­ness­es nat­ur­al ele­ments to dri­ve ener­gy effi­cien­cy and reduce costs.

In Texas, archi­tects are often look­ing for pas­sive design solu­tions that help cool homes in the sum­mer and keep them warm in the win­ter. To achieve this, pas­sive design must focus on build­ing ori­en­ta­tion, size, and con­fig­u­ra­tion of win­dows, and mate­ri­als and sys­tems that can both heat and cool homes based on sea­son­al and dai­ly vari­a­tions.

Managing Direct Energy Gains

Giv­en the large tem­per­a­ture swings through­out the day and the mix of heat­ing and cool­ing days, Texas is ide­al­ly suit­ed to pas­sive house design. In pas­sive design, build­ings in the north­ern hemi­sphere are designed with south-fac­ing win­dows to bring in as much sun­light and heat as pos­si­ble into the home in the win­ter.

In the sum­mer, shad­ing sys­tems over these win­dows block direct sun­light from enter­ing the home, keep­ing the inside cool­er. With more than 300 sun­ny days in El Paso each year, there’s a lot of ener­gy to be gained and the home could be over­heat­ed with­out pre­cau­tions. Pas­sive hous­es often incor­po­rate triple-glazed win­dows, as well as over­hangs and shad­ing, to avoid over­heat­ing.

For instance, this pas­sive house uses tra­di­tion­al-look­ing over­hangs above win­dows in direct sun­light, while still incor­po­rat­ing the archi­tec­tur­al feel of the home.

Land­scap­ing can also be used to help man­age direct ener­gy gains. In cold­er cli­mates, shade from trees can be a lim­i­ta­tion to solar heat­ing, but on hot Texas sum­mer days, strate­gi­cal­ly plant­ed trees can help man­age solar over­heat­ing.

Thermal Mass


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One of the key com­po­nents of pas­sive design is ther­mal mass. That’s when you use build­ing mate­ri­als that help to reg­u­late con­sis­tent inter­nal tem­per­a­ture even while exter­nal con­di­tions change with weath­er or time of day. Select­ing build­ing mate­ri­als designed with ther­mal mass in mind is crit­i­cal to the suc­cess of pas­sive design.

Archi­tects and home builders fre­quent­ly choose nat­ur­al or tra­di­tion­al build­ing mate­ri­als like stone, con­crete, and brick because of their ther­mal mass prop­er­ties. These mate­ri­als absorb and hold heat bet­ter than wood or steel.

If you’re look­ing for an engi­neered solu­tion, ICF wall sys­tems such as Bau­tex Blocks and Bau­tex Wall Sys­tem use insu­lat­ed con­crete, which is ide­al­ly suit­ed to keep Texas homes cool­er dur­ing sum­mer heat and to pre­serve warmth on cold­er win­ter days. Plus, Bau­tex prod­ucts have the added advan­tage of being more cost effec­tive than many oth­er tra­di­tion­al options.

Night Purging

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If you’re warm, open a win­dow.” We’ve all been told this at least once in our lives. There is noth­ing new about night purg­ing as a way to pas­sive­ly cool a space. Night purg­ing is as sim­ple as leav­ing your win­dows open at night to help cool off liv­ing areas after a warm day.

Pas­sive design uses the basic prin­ci­ple of night purg­ing and then takes it fur­ther, bring­ing in cool night air through ven­ti­la­tors or specif­i­cal­ly designed mechan­i­cal units. And where these units gen­er­ate heat through motors, this heat can be recov­ered and recy­cled into domes­tic hot water sys­tems, fur­ther low­er­ing ener­gy demands and costs.



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Air­tight­ness is crit­i­cal to the suc­cess of pas­sive design. Why go to all the trou­ble of build­ing a home that bal­ances its own air tem­per­a­ture if that air is just going to escape out of poor­ly sealed walls and win­dows? But improved air­tight­ness also runs the risk of poor ven­ti­la­tion, leav­ing the indoors feel­ing stale.

The design­ers of Tex­as­’s first pas­sive house acknowl­edged this is a com­plex prob­lem requir­ing a detailed solu­tion. A heat pump can adjust the indoor tem­per­a­ture as need­ed while an ener­gy recov­ery ven­ti­la­tor draws in out­door air, fil­ters it, cir­cu­lates and flush­es out stale inte­ri­or air. Final­ly, a humid­i­fi­er man­ages humid­i­ty of occu­pant com­fort.

A side ben­e­fit of pas­sive design’s air­tight­ness require­ments is that homes often enjoy improved indoor air qual­i­ty in com­par­i­son to tra­di­tion­al­ly designed hous­es. With reg­u­lar fil­tra­tion, prop­er humid­i­ty and ade­quate fresh air exchanges, over­all air qual­i­ty is improved, mak­ing pas­sive homes ide­al­ly suit­ed for res­i­dents with aller­gies and envi­ron­men­tal sen­si­tiv­i­ties.

Are You Ready for Passive Design?

As the demand for pas­sive design and Net Zero com­mu­ni­ties grows in Texas, it’s impor­tant to under­stand the stan­dard require­ments and what it will take to go from con­cept to con­struc­tion. Bau­tex’s line of ICF alter­na­tives can help get you there. To find out how we can help, con­tact us today.