Building Energy-Efficient and Affordable Homes in Hot and Humid San Antonio


Home builders like River Star Homes and building material man­u­fac­tur­ers like Bautex Systems are tackling the challenge of building energy-efficient and afford­able homes in hot and humid San Antonio, Texas.

Building energy-efficient homes in San Antonio begins with the design of a tight and well insulated building envelope. When builders utilize the Bautex Wall System they create highly insulated, moisture-resistant, and airtight homes that are critical in the hot and humid climate of San Antonio.

Afford­able Housing Shortage in San Antonio

Building energy-efficient, low main­te­nance and afford­able homes in San Antonio is needed to accom­mo­date San Antonio’s growing pop­u­la­tion and shrinking inventory of rea­son­ably priced and quality homes. The challenge to builders and archi­tects in San Antonio is to construct homes a new buyer can both afford to buy and live in.

Specif­i­cal­ly, in San Antonio, energy-efficient design is essential for ensuring low long-term energy and main­te­nance expenses. New homes must be afford­able and energy-efficient to meet the housing demands of San Antonio.

Building Energy-Efficient and Afford­able Homes in Hot and Humid San Antonio 

Designing an energy-efficient home in San Antonio must consider the climate and geography of the region. San Antonio lies in south-central Texas, about 140 miles from the Gulf of Mexico. Most of the time, easterly, south­east­er­ly winds off the Gulf of Mexico dominate San Antonio.

The steady flow of wind brings moisture to the area, resulting in a humid sub­trop­i­cal climate. Much of the year, the relative humidity in San Antonio is above 80 percent in the early morning. Humidity drops to near 50 percent in late afternoon.

The average monthly tem­per­a­tures in San Antonio range from the 50s in winter to 80s in summer. However, summers are often long and hot with daily maximum tem­per­a­tures above 90 degrees over 80 percent of the time. Address­ing the extreme heat and humidity in San Antonio is critical to building an energy-efficient and afford­able home.

Critical Elements of Energy-Efficient and Afford­able House in San Antonio

Builders and archi­tects of afford­able homes in San Antonio must consider energy-effi­cien­cy for all con­struc­tion. However, when con­struct­ing afford­able housing in San Antonio, energy-effi­cien­cy is essential to ensuring that a homeowner can handle the day-to-day expenses and long-term main­te­nance costs inherent in home ownership.

Critical elements of an energy-efficient home in San Antonio include proper building ori­en­ta­tion, con­tin­u­ous insu­la­tion in the walls and roof, airtight building envelope, quality and properly installed windows and doors, and a well designed HVAC system.

Energy-Efficient Homes in San Antonio Need Robust Building Envelopes

Critical design elements for a robust building envelope include con­tin­u­ous insu­la­tion and air and moisture barrier. A con­tin­u­ous air and moisture barrier minimizes air infil­tra­tion and moisture intrusion, which is essential to creating an energy efficient and durable home in San Antonio. Moisture resis­tance is critical to stopping rot and the growth of mold and mildew, which can diminish the indoor envi­ron­men­tal quality (IEQ) of a home.

Con­tin­u­ous insu­la­tion elim­i­nates thermal bridging through the building envelope and maintains the energy per­for­mance of the insu­lat­ing material. Up to 25% of con­ven­tion­al­ly framed walls has no insu­la­tion. Therefore, the insu­la­tion in the stud cavities only provides a fraction of the rated R‑value that is adver­tised by the man­u­fac­tur­er. Con­tin­u­ous insu­la­tion systems provide the full rated performance.

The envelope must consider all the exterior elements of the house: the walls, roofing, foun­da­tions, doors, and windows.

High Per­for­mance Walls of Energy-Efficient Homes

The walls are a critical component to stopping heat gains and producing a robust envelope of an energy-efficient house. Several natural occur­rences affect the effi­cien­cy of the walls: con­duc­tion, con­vec­tion, and thermal radiation. The walls of an energy-efficient building should have low-thermal-con­duc­tiv­i­ty and a high effective R‑value4. The design of an energy efficient wall also incor­po­rates materials with high thermal mass which amplifies the per­for­mance of the walls. . Energy-efficient walls are a critical element of an efficien tbuilding envelope.

Building an Energy Efficient Home in San Antonio with the Bautex Wall System 

The Bautex Wall System is a superior, high thermal mass product for producing a durable building envelope for an energy-efficient and afford­able home in San Antonio. The Buatex Block meets the thermal per­for­mance mandated by the IRC and provides a high-level of con­tin­u­ous insulation.

The Bautex insulated concrete blocks provide an R‑14 con­tin­u­ous insu­la­tion that meets, the latest building and energy codes (2015 IECC). Also, applying the Bautex AMB 20 air and moisture barrier to the Bautex Blocks produces a moisture-resistant, airtight house, critical in humid San Antonio.

The Bautex Wall System is the ideal choice for energy-efficient wall con­struc­tion for afford­able homes in San Antonio.

The Roof of an Energy-Efficient Home

  • A cool roof is crucial to the design of a home in San Antonio. Cool roofs protect against solar heat gain and keep the attic and house cool. Thermal mass materials for a cool roof like clay, tiles, or slate that are reflec­tive or have light colored pigments that reflect the sunlight are excellent options for cool roofs. 

Insu­lat­ing The Foun­da­tion on an Energy-Efficient Home

Installing a con­tin­u­ous layer of rigid foam insu­la­tion on the exposed slab edges of concrete foun­da­tions will increase the energy effi­cien­cy of a home. A sig­nif­i­cant amount of heat flow can occur from the inside of a home through the foun­da­tion where it is exposed to the outside. Including this insu­la­tion detail is extremely ben­e­fi­cial, but is rarely done correctly. 

The Glazing System of an Energy-Efficient Home

Home Ori­en­ta­tion of an Energy-Efficient Home in San Antonio

Site ori­en­ta­tion of a house is critical for taking advantage of the sun’s energy. For instance, in the Northern Hemi­sphere homes should be oriented north-south. The north-south ori­en­ta­tion limits direct sunlight during the summer (which lessens cooling demands) while max­i­miz­ing sunlight during the winter (which reduces heating requirement).

Room Location of an Energy-Efficient Home in San Antonio

Room con­fig­u­ra­tion is also an essential design con­sid­er­a­tion of an energy-efficient home in San Antonio.

  • North facing rooms have good sun most of the day and are perfect for the main living spaces like living, family, land dining rooms.
  • East facing rooms have good sun in the morning and are cool in the late afternoon, which is ideal for bedrooms, kitchens, and breakfast nooks.
  • South-facing spaces have low levels of sunlight and are nice areas for garages, laundries, and bathrooms.
  • West facing rooms get the late day sun, which is not good for kitchens and bedrooms.

Windows of an Energy-Efficient Home in San Antonio

Windows of an energy-efficient home in San Antonio should face north or south. Avoid east- and west-facing windows because they con­tribute more to over­heat­ing than north- or south-facing windows.

Ductwork Location of an Energy-Efficient Home in San Antonio

For an energy-efficient new house in San Antonio, locate the ductwork inside the home’s envelope. Ducts placed in uncon­di­tioned spaces can increase cooling expenses by 15 percent. Fur­ther­more, in hot and humid regions moisture will collect on the over­heat­ed ductwork.

San Antonio Needs Energy-Efficient and Afford­able Housing

Builders in San Antonio, Texas, like River Star Homes, are chal­lenged with con­struct­ing afford­able and energy-efficient homes for the area’s growing pop­u­la­tion. Building homes in hot and humid San Antonio require detailed attention to energy-efficient design. 

Energy-efficient design will ensure home­own­ers have afford­able energy costs and durable homes. Please visit Bautex™ Wall Systems for more infor­ma­tion on building energy-efficient and afford­able homes in San Antonio, Texas.

1Thermal con­duc­tion is when warm molecules spon­ta­neous­ly move towards and collide with cooler molecules. The effective R‑value of a home’s wall assembly is its resis­tance to con­duc­tion (the movement of hot molecules towards cooler molecules).

2Thermal con­vec­tion is the transfer of heat from a warmer space to a colder space by the flow of liquid or air molecules. A tightly sealed building envelope stops this flow, often with an air and moisture barrier.

3Thermal radiation transfers heat from a warm area to a cooler area by elec­tro­mag­net­ic waves, which for homes is mainly the sun’s rays.

4A build­ing’s wall assembly resis­tance to this flow is measured by its effective R‑value. The effective R‑value includes all the materials used in its con­struc­tion: the studs, siding, drywall, fiber­glass batts, plywood or OSB sheathing, water control plane. The higher the R‑value, the less the con­duc­tiv­i­ties of the wall assembly.

5Thermal mass is the potential of a material to absorb and store heat energy. High thermal mass materials help stabilize tem­per­a­ture shifts within a home by slowing the rate of heat transfer.