Energy-efficient new homes, certified for South Texas

BUILT TO SAVE® is a voluntary, energy efficiency certification program that identifies new homes built to outperform similar homes built only to minimum building code requirements. BUILT TO SAVE® certified homes are inspected and tested by an independent third-party RESNET certified energy rater and are guaranteed by the rater to have met the strict requirements of the program.

HERS IndexLower is more efficient

2026 Leading Energy-Efficient Builders in the Rio Grande Valley: Caza Group, Divine Custom Homes and Affordable Homes of South Texas

A Built to Save® home: lower utility bills, third-party certified, more comfort, sealed tightly, better indoor air

≤ 63

HERS score to qualify, or 5% more efficient than code

2015 IECC

Minimum energy code every home must meet

RESNET

Independent rater inspects before drywall and tests at completion

Public

Any certified home can be looked up by address

Building homes in the Valley, or buying one?

For builders

Certify your RGV homes with Built to Save®

Certification turns “energy efficient” from a sales claim into a score an independent rater measured. Buyers can look up every certified home by address.

Directory and Guide placement: your company in the Built to Save® builder directory and, once your first home is certified, in the program's two-page ad in the RGV New Homes Guide
MVEC cash incentives on certified homes in MVEC territory — See current builder rebates
Trademark use: put the Built to Save® mark in your print and online marketing while your membership is active
A public record buyers trust: each certified home appears in the database with its certificate

For homebuyers

Buying a new home in the RGV

A certified home comes with a written HERS score, where a standard reference home scores 100 and lower is better. To qualify, a home must have a HERS score of 63 or below, or be 5% more energy efficient than code.

Raters and suppliers: find a RESNET rater or register as a supplier member.

The process

How does Built to Save® certification work?

A builder registers with the program, then hires an independent RESNET-certified rater. The rater models the plans, inspects insulation and air sealing before drywall, and runs blower-door and duct-leakage tests at completion. Homes with a HERS score of 63 or below, or 5% more energy efficient than code, earn certification and a listing in the public database.

Builder registers

Membership renews every year and covers all of the builder’s certified homes.

Rater models the plans

Before construction starts, an independent rater reviews the floor plans and the Manual J load calculation.

Pre-drywall inspection

With the walls still open, the rater checks insulation, air sealing and duct sealing.

Final testing

Blower-door and duct-leakage results set the final HERS score

Read the full energy-efficient home certification process in Texas

Builders already certifying with Built to Save®

Valley builders who put their homes through independent testing and list them where buyers can check.

Member since 2014

Affordable Homes of South Texas

See featured builders →Rio Grande Valley

2026 Leading Builder

Member since 2014

Divine Custom Homes

See featured builders →Rio Grande Valley

2026 Leading Builder

Member since 2019

Caza Group, LLC

See featured builders →Rio Grande Valley

2026 Leading Builder

For Rio Grande Valley builders

How do Builders join Built to Save®?

Register your company online, then hire any independent RESNET-certified rater for each home you want certified. The rater inspects before drywall and tests at completion. Homes with a HERS score of 63 or below, or 5% more energy efficient than code, earn the certificate and a public database listing. Membership renews each year, and MVEC rebates help offset inspection costs in its territory.

What it costs: $175 a year for membership, $205 per certified home for the certificate and panel decal, and about $450 per home paid to your rater. MVEC rebates offset inspection costs in its territory.

Aerial view of a new-home subdivision in the Rio Grande Valley

Three steps to
certified homes

Step 1Register your company online.
Open the form ↗
Step 2Hire any RESNET-certified rater.
Find a rater ↗
Step 3Pass the tests, get certified and listed.
See how it works ↗

Watch how to register

The video walks through the online builder registration form. Have your company contact details, EIN and a high-resolution logo file ready before you start.

7 min 35 sec · YouTube

What changes when a home is certified?

To qualify, a home must have a HERS score of 63 or below, or be 5% more energy efficient than code. On the HERS scale the reference home scores 100, and lower is more efficient. The rater measures the score on site with blower-door and duct tests, so buyers get a tested result instead of a builder’s description.

Home Energy Rating System (HERS) IndexLower is more efficient

More of what you want

Less of what you don't

Where are Built to Save® homes built?

Certified builders work across the Rio Grande Valley of South Texas, including McAllen, Edinburg, Mission, Pharr, Weslaco, Harlingen, San Benito and Brownsville. MVEC cash incentives apply to homes in Magic Valley Electric Cooperative’s territory.

Ask at the sales office

“Does this home have a Built to Save® certificate, and what’s its HERS score?” Check an address

Quick answers

Built to Save® questions

For builders

What does it cost a builder to join Built to Save®?

Builder membership costs $175 a year. Each certified home adds $205 for the certificate and the electrical-panel decal. The rater's pre-drywall and final inspections typically cost about $450 per home, paid directly to the rater.

How does a builder join Built to Save®?

Register online and renew your membership each year. Builders certify at least one home a year to keep using the Built to Save® trademark and stay listed as an active member.

What rebates can Built to Save® builders get?

Magic Valley Electric Cooperative (MVEC) pays cash rebates on certified homes in MVEC territory to offset inspection costs. Current amounts are on the builder rebates page.

Who sponsors Built to Save®?

Magic Valley Electric Cooperative (MVEC) sponsors Built to Save®. MVEC also funds the program's builder rebates on certified homes in its service territory.

For homebuyers

What is Built to Save® certification?

A voluntary energy-efficiency certification for new homes in the Rio Grande Valley of South Texas, sponsored by Magic Valley Electric Cooperative (MVEC). Every certified home has a HERS score of 63 or below, or is 5% more energy efficient than code, verified by an independent RESNET-certified rater.

What HERS score does a Built to Save® home need?

A home must have a HERS score of 63 or below, or be 5% more energy efficient than code, to qualify. Every home must also meet the 2015 IECC as a minimum.

Who inspects a certified home?

An independent RESNET-certified energy rater. The rater inspects the home before drywall and tests it again at completion.

How do I check whether a home is certified?

Search the certified homes database by address, or ask the builder for the home's certificate and HERS score.

Updated October 2026