Looking for an energy auditor in Longmont, CO? Describe your project once and up to three certified energy auditors who work in Longmont and Boulder County get back to you with a quote. It's free and there is no obligation.
Longmont is home to about 99,818 people (2024 Census Bureau estimate), a stable community (+0.9% since 2020). With 3,411 people per sq mi, it is a suburban area. Older homes and long heating or cooling seasons make energy audits worthwhile here.
Longmont at a glance
- Population (Census Bureau estimate, 2024)
- 99,818 (+0.9% since 2020)
- Rank in Colorado
- 13th of 271 cities and towns
- Land area
- 29 sq mi
- Population density
- 3,411 people per sq mi (suburban)
- Type
- City (Longmont city)
- Main county
- Boulder County
What to check before hiring in Longmont
- Certification: choose a RESNET or BPI certified professional.
- Rebates: in Colorado, check your utility's programs before booking: some require their own approved auditors.
- Test-in, test-out: a blower door test before and after upgrades shows the result.
- Price drivers: home size, tests included and report detail.
Useful official resources
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ENERGY STAR
Energy efficiency guidance for homes.
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RESNET
Find a certified HERS rater.
Services available in Longmont
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Home energy audit
Whole-home assessment with blower door test and infrared scan, with a prioritized list of upgrades.
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HERS rating
HERS Index rating of a new or existing home by a RESNET-certified rater, for code compliance or programs.
Frequently asked questions in Longmont
How much does an energy audit cost in Longmont, CO?
It depends on the home and the tests. Describe your home: auditors who serve Longmont reply with a quote.
How long does it take?
Usually two to four hours on site.
Will the auditor sell me upgrades?
Some do; an independent auditor gives a neutral list.
Which certified energy auditors will contact me?
Up to three independent certified energy auditors who serve Longmont and the surrounding area, chosen for the service you need. Your details are shared only with your consent.
Source: U.S. Census Bureau, Population Estimates Program (Vintage 2024) and Gazetteer Files (public domain), imported on 10/31/2026. Figures describe the incorporated place or county as published; they are shown for information only.