Energy Vanguard Blog

A Few of My Favorite Filter Photos

Let's Stop Using the Word "Breathe" for Buildings

Falling Electricity Rates, Bill Tracking, and Energy Efficiency

Humidity in a Spray Foam Attic

The Cost of Solar Energy Keeps Dropping, But...

7 Things I Learned at the North American Passive House Conference

Grading an Attempt to Get Ducts Inside Conditioned Space

How Dirty Is Your State's Electricity?

More on Air Conditioner Sizing Rules of Thumb

Air Conditioner Sizing Rules of Thumb Must Die

Installing an Exhaust Fan During a Bathroom Remodel

3 Reasons to Remove Attic Floor Insulation in a Spray Foam Attic

Can You Ventilate a Home with Attic Air?

Only One Person Can Fix the Passive House Rift

Why a New Standard for Passive House?

3 Cool Products I Saw at the Passive House Conference in NYC

The 2018 Building Code Makes a Change in Ventilation

How I Achieved a 21% Increase in Airtightness

How Much Insulation Do You Need in a Passive House?

Is Global Energy Use Getting Better?

The Great Ventilation Battle Shifts to RESNET

The Evolution of Passive House in North America

MAD AIR:  Duct Systems, Infiltration, & Their Interactions

Daniel Boone's Dew Point Problem

Signs of a Bad Duct Installation

Ventilating High-Rise Multifamily Buildings — A First Look

In Praise of Those Who Do the Dirty Work

Building Science Word of the Day:  Interstitial

How to Fix a Leaky, Underinsulated Exterior Wall

BPI Pilots New Healthy Homes Evaluator Microcredential

7 Reasons to Gut Your Bathroom When You Remodel

A Sign of a Good Duct Installer

Questions on Building a Passive House in a Humid Climate

The Timeless Nature of Building Science Principles

The Water Efficiency Rating Score (WERS) Launches

An Air Barrier Is NOT a Product

Design Flaws That Can Rot Your House

4 Types of R-Value

Air Flow Pathways in a Leaky Bathroom Wall

2 Home Performance Music Videos You Just Gotta See

Foam Insulation and Global Warming, Part 3

Adventures in Hotel Bathroom Ventilation

The Humid Climate Conference Is Gonna Rock!

Does Your Water Resistive Barrier Really Resist Water?

A Vivid Demonstration of the Benefit of Exterior Insulation

The Misleading "Science" Behind Heat and Insulation

Down and Out Is the Rule for Draining the Rain

The Tale of the New Mexico Dehumidifier

Foam Insulation, Global Warming Potential, and BS

Pushing Through the Hard Parts

What Is Home Performance? Part 1

An Unexpected Benefit of Encapsulating a Crawl Space

Is This the Worst Duct Retrofit Ever?

What's the WERS?

How to Get the Best Possible New Tract Home

Heat Is a BTU-tiful Thing!

An Old Home in New Orleans Gets New Sheathing

HVAC Hacks and Other Screwups — The Backstory

Can You Cool Your Home with Crawl Space Air?

The Surprising Building Science History Behind the Revolving Door

A Tale of Two Roofs - Frost, Snow, and Attic Heat Loss

Unvented Gas Appliance Industry Falls Flat at ASHRAE Meeting

Even New Windows Won't Stop This Heat Loss

What Is the Best Indoor Relative Humidity in Winter?

Increasing Diversity at the Best Home Performance Conference

Another Way to Prevent Your Garage from Making You Sick

The Benefits and Drawbacks of Skylights

7 Wishes for a Green '16

The World of Smart Begins to Grow Up

My Top 10 Energy Efficiency Articles and Ideas of 2015

Big Blowout in the Plastic PortaPotty

Don't Talk to Me About Vapor Barriers!

Are You Confusing Insulation with Air Barriers?

Accidental Dehumidification - A Preventable Mess

Valuing Energy Efficiency in the Electricity Market

A Simple, Inexpensive Way to Better Airtightness

2 Decades of Danny's Home Energy Data

Electricity Demand and the Duck Curve

Do Boilers for Home Heating Actually Boil Water?

10 Uncommon Tips for Winterizing Your Home

Winterizing Your Home? Don't Caulk the Windows!

Enterprise Green Communities — The Best Program You've Never Heard of

Clarifying the Confusing Calculations for Zero Energy Buildings

Do Energy Efficient Homes Cause Asthma?

The Department of Energy Makes a Choice in the Net Zero Debate

The Science of Sag - Flex Duct and Air Flow

7 Tips & Tricks for Blower Door and Duct Leakage Testing

It's Time to Settle the Net Zero Energy Controversy!

Fundamentals of Psychrometrics, Part 3

4 Passive House Conference Talks I Can't Wait to Hear

A Canadian Building Science Treat for Your Weekend!

The Best Way to Cool Your Attic

10 Essential Steps to Building a Pretty Good House

The Secret to Moving Air Efficiently through Your Duct System

My New Favorite Duct Disaster

Must the 3 Little Pigs Die?

The Problem with Relative Humidity

Fun in the Sun: The 2015 Solar Cooking Festival

Will Shading Your Air Conditioner Save You Money?

The Wonderful, Blunderful World of Construction

A Sticky Psychrometric Situation: Wet Bulb Temperature

Could an Energy Code Really Be So Simple?

OSHA Has New Rules for Working in Crawl Spaces and Attics

3 Cool Videos about Hydrophilic, Hydrophobic, & Hygroscopic Materials

Is Evaporative Cooling the Answer to High Air Conditioning Costs?

17 Reasons I Love Working with Buildings

Psychrometrics, Part 2 - The Quantities in the Chart

How to Clean Out Your Air Conditioner's Condensate Line

Psychrometrics - Impenetrable Chart or Path to Understanding?

Does the Nest Learning Thermostat Save Energy?

This Lack of Building Enclosure Design Makes Extra Work

Nest Thermostat Data Unveiled at ACI Conference

Why Did the Chicken Go to the ACI Conference?

Moisture Transport, Sorption Isotherms, and Aliens Drinking Beer

Introduction to the Physics of Water in Porous Materials

Joe Lstiburek's Ideal Double-Stud Wall Design

My Passion for Building Science Education and Bad Contractors

Is This the End of the Double-Wall, Cold Sheathing Scare?

An Interview with Terry Brennan — a Building Science Pioneer

The Paranormal - Building Science Nexus

7 Reasons to Go to the ACI National Home Performance Conference

A New Way to Cool Your Attic - Powered Attic Mini-Split Heat Pumps

California Mistakes Put Spray Foam Insulation on the "Bad List"

Insolation Is Not a Typo for Insulation

The Sad Joke of Higher Furnace Efficiency Standards

A Beautiful Solar Home in Utah Nears Net Zero Energy Use

The Problem of Getting Air for Atmospheric Combustion Appliances

The Energy Vanguard Blog Turns 5

How NOT to Retrofit a Furnace in a Spray Foam Insulated Attic

Modeling Is Not a Four-Letter Word

The Layers and Pathways of Heat Flow in Buildings

Should We Change the HERS Reference Home's Energy Code?

New Mexico Green Builders Create Water Efficiency Rating System

The Drainage Plane Flashing Battle Continues

Solar Electricity: "The Final Source of Energy"

A Year Full of Building Science Conferences

The One Thing I'd Love to See Building Enclosure Workers Do

Fiberglass Insulation Manufacturer Gets Serious About Installation

The 3 Types of Heating and Cooling Loads

The Fundamentals of Heating and Cooling Degree Days, Part 2

The Gap Between Stupid and Hurt Is Narrowing

The Experts Discuss Hygrothermal Analysis

2 Bad Ways to Install Windows the Hard Way

The Fundamentals of Heating and Cooling Degree Days, Part 1

Passive House Builder Hammer & Hand Helps You Fight the Devil

How Much Should You Worry About Asbestos in the Home?

Building Enclosure Blunder in the Basement

The Diminishing Returns of Adding More Insulation

Insulation to Go - Creativity in the Attic

Are You Being Responsible with Numbers?

Amazon to Use Server Farm Waste Heat for Office Heating

RESNET Changes Training Policy with Interpretation

On the Edge: The North American Passive House Conference

An Energy Recovery Ventilator Is NOT a Dehumidifier

All Over the Map — The Imprecision of 24 California HERS Ratings

This Thermostat Setting Can Cost You Money and Make You Sick

My Big Fat Oversized Air Conditioner

Why Is RESNET Limiting Its Options for Improvement?

Moisture and the Quirkiness of OSB

5 Reasons to Attend the Passive House Conference in California

Why Is Clark Howard Giving Bad Energy-Saving Advice?

Are You Making This Mistake with Humidity?

Matt Risinger's Building Science Summer Camp Interviews

The Pen Test — A Control Layers Tool for Architects and Contractors

4 Ventilation Quotes That Will Rock Your IAQ World

Can You Save Money by Closing HVAC Vents in Unused Rooms?

FBI Investigates R-22 Substitute Air Conditioner Refrigerants

A Line in the Sand — The Dew Point Duct Duel

The Sucking and the Blowing — A Lesson in Duct Leakage

Is the Aros Smart Window Air Conditioner Worth the Hype?

Fermi Problems, Blower Doors, and the Compressibility of Air

How Is a Blower Door Like a Hydraulic Jack? Pascal Knows!

How to Determine the Size of Your Central Air Conditioner

Why Is This Obsolete Supply-Only Ventilation Method Still Used?

Our First Hybrid HERS Rater Training - How Did We Do?

The #1 Reason Power Attic Ventilators Don't Help

Hobos in the House - Let the Data Logging Games Begin!

Stockton Project Demonstrates Huge Home Energy Savings

Curiosity Is the Door to Passion

What Is the Difference Between Energy Efficiency and Efficacy?

The James Brown Blower Door Video

The Great Ventilation Debate - Live at Affordable Comfort!

So Close Yet So Far - The Aqua Tower and Passive House

12 Resources for Learning & Teaching Building Science

What Happens When You Put a Plastic Vapor Barrier in Your Wall?

My First Affordable Comfort Conference

Will Open-Cell Spray Foam Insulation Really Rot Your Roof?

With Ceiling Fans, Bigger Is Better

Long Live the One-Week HERS Rater Training!

The 2 Primary Causes of Reduced Air Flow in Ducts

US Department of Energy Reveals Net Zero Mass/Energy House

Who's on Your Insulation Crew?

4 Smart Building Science Learning Opportunities for You

A Great Success: Classic 1970s Passive Solar Home Turned Net Zero

These Ain't Yer Grandpappy's Heat Pumps

Solving a Crawl Space Water Mystery

RESNET Bungles the Adoption of Combustion Safety Testing

Is It Time To Give Up On High-Performance Homes?

A Pi Day Physics Lesson on the Induction Cooktop — With Dancing!

The Ventilation Debate Continues: Interview with Dr. Iain Walker

A Home Performance Trailer as Good as Pap-Paw's Truck

The North American Passive House Conference Is in San Francisco

4 Ways a Bad Duct System Can Lead to Poor Indoor Air Quality

The Stack Effect in Plastic

Why Are Heat Pumps So Dumb About Frost?

John Krigger: Effective Combustion Safety and Efficiency Testing

Will You Be at BE? NESEA's Building Energy Conference, That Is

Frost on Indoor Walls - A Dramatic Insulation Failure

Are We Off Track With Combustion Safety Testing?

Why Does My Heat Pump Frost Over?

What If Home Builders Had to Pay the Energy Bills?

Look for Me by the Question Mark

What's That Ice Chest Doing in This Attic Duct System?

Air Barriers, Vapor Barriers, and Drainage Planes Do Different Jobs

The Two-Inch Nightmare Snow Storm That Brought Down Atlanta

6 Materials That Drain the Rain on the Plane and Keep A House Dry

Ice Spikes, Building Science, & Sci-Fi Movies — A Little Friday Fun

Can Occupants Be Trusted to Control Their Home's Ventilation System?

Does a Gas Furnace Dry Out the Air in Your Home?

When It Comes to Ice Dams, You CAN Fix Stupid!

Go Up, Go Small, and Get Those Ducts Inside Conditioned Space

Building Science Schmilding Science; Let's Do Things Right in 2014

2013: A Look Back at the Year in Building Science

The Case of the Duct That Wasn't There

The Mixed-Up IAQ and Infiltration Blues

Cold Air Is Dry Air

Will Higher Ventilation Rates Reduce Student Absences in School?

Bats Can't Live Under a Thermal Bridge

A December Building Science Bonanza

A Net Zero Energy Home in a Beautiful Green Community

Is Energy Efficiency More Important Than Indoor Air Quality?

Why Did Painters Refuse to Paint Insulated Houses in the 1930s?

Beware of Roofers in Homes with Spray Foam Insulation

Does Your Spray Foam Insulation Need a Thermal or Ignition Barrier?

A First Sentence to Rival Gabriel García Márquez's Firing Squad

The 2013 ACEEE State Energy Efficiency Scorecard: No A's & 43 F's

Fixing an Old House? Follow Einstein's Advice

A Halloween Homage to Those Things That Live—and Die—in Our Homes

Is the ENERGY STAR New Homes Program Dying?

Georgia Power Fills the Void Left by ENERGY STAR

5 Easy Steps to Understanding WUFI - Memento Style

Take a Hot Solar Shower in the Backcountry with the Road Shower

What Happens in the Real World Stays in the Real World

The 2015 Energy Code Will Have a HERS Rating Compliance Path

This Little Ventilation Mistake Can Lead to Comfort Problems

Why Do So Many Expensive Homes Get Walmart-Class HVAC Systems?

Advice to Architects: Draw Those Attic Kneewall Sections Right

Total Energy Use Down in US, Wind & Solar Up

Confessions of a Building Science Zealot

A Surprisingly Common Cause for High Energy Bills

Have You Seen What's in Your Hotel Room Air Conditioner?

Is Mike Rowe Right about the War on Work?

The Secrets of Liars — How to Detect an Internet Solar Energy Scam

What Is the Best Way to Deal with Crawl Space Air?

The #1 Question to Ask before Putting Spray Foam in Your Attic

Don't Try This Recycling Trick at Home!

Patent Troll Tactics Target Infrared Camera Use of Home Inspectors

Why Are Your New Homes Missing out on the $2000 Tax Credit?

Graphite in Insulation — Better R-Value but Can You Write with It?

5 Inescapable Reasons HVAC Contractors Need to Be in Home Performance

The Shocking Truth About Heat Pumps

This Little Hitch Snares ENERGY STAR Homes

Warning: Skipping This Step with New HVAC Systems Can Lead to Misery

Yowza! The Energy Vanguard Blog Crashes the 500 Barrier

Passive House — The Only Place Where Real Innovation Is Happening?

Photo Highlights from the 2013 Building Science Summer Camp

ASHRAE 62.2 Committee Chair Predicts Confusion & Frustration from BSC-01

Are You Making These Mistakes with Your Garage?

11 Building Science Secrets Every Home Builder & Remodeler Should Know

5 Good Ways & 1 Bad Way to Get Your Ducts Inside Conditioned Space

Are You Using Vent Caps for Duct Leakage Tests Yet?

Interview with Dr. Joe Lstiburek — The Ventilation Debate Continues

Do Programmable Thermostats Save Energy?

Is Mushroom Insulation the World's Greenest Insulating Material?

The Importance of Mentoring, in Building Science and in Life

Radon Venting—Do It During Construction or Add a Zero

Lstiburek Has New Ventilation Standard—Resistance May Not Be Futile

Propane in Your Air Conditioner? Bad Idea!

GUEST POST: An ENERGY STAR V3 Success Story in a Round House

Greenwashing Is Alive and Well in the New Homes Market

Beautiful Duct System in a Beautiful Crawl Space! Was I Dreaming?

The High Price of R-22 for Air Conditioners May Close the Loophole

4 Ways to Define Net Zero Energy Use in Buildings

Latent Heat is the Wicked Witch of the South

The Wicked Witch of the West, Phase Changes, and Building Science

A Day in the Life of an Air Conditioner Service Professional

An Interesting Way To Freeze Your Air Conditioner Coil

Tips & Trivia for a New Air Conditioning Season

Are Spray Foam Contractors Putting Themselves at Risk?

The Top 10 Mistakes I Made in Building a Green Home

Man Abandons Man-Cave Because of Hidden Building Enclosure Problems

A Great Tool for Checking Insulation in Walls

3 Reasons Your 3 Ton Air Conditioner Isn't Really 3 Tons

NIST Takes on the Net Zero Energy Home Challenge

Snakes in an Attic — The Ductopus's Cousin Strangles Bath Fans

The Time Value of Money and the Energy Efficient Mortgage

Does Your Air Barrier Work in Both Directions?

Are You Breathing Dead Possum? — Crawl Spaces, HVAC, & IAQ

Physics Taught Me the Chinese Principle of Success

107 Acronyms & Initials for Home Energy Pros

A Building Enclosure Double Disaster - Control Freaks Missing Again

Surprise! I'm an Air Conditioner Compressor Killer

A Really Cool Net Zero Energy Home in the North Carolina Mountains

My Interview with the Inventor of the Turbo Thermo-Encabulator Max

Big News: The R-Value of Insulation Is Not a Constant

Do You Know Your Building Science Climate Zone?

Guest Post: The Fatal Flaw in Advanced Framing, Part 2

Guest Post: The Fatal Flaw in Advanced Framing, Part 1

Guest Post: The Elephant in the Room—HVAC for High Performance Homes

ACCA vs BPI—The Brouhaha Over Home Energy Audit Standards

How Much Energy Is Wasted on Cheap Crap Made in China?!

Throwing the Building Science Learning Curve for a Loop

Breaking News: Tea Party Successful in Outlawing Insulation

Structural Insulated Panels — An Easier Way to Build an Airtight Home

5 Things You Can Do to Build for Success When Business Is Slow

The Mad Hatter, Isaac Newton, and That Old Thermostat

Does a Heat Pump or Air Conditioner Condenser Need to Go Outdoors?

Does Texas Use More Energy for Heating or for Cooling?

Ice Dam Bandaid Solution: Heat Strips on the Roof

What?! You Can't Have an Open Wood-Burning Fireplace in Your Home?

The Energy Nerd's Tour of Green Homes in Georgia

Home Building Is Like Skiing

Vented Crawl Spaces and the Psychrometric Chart Are Not Friends

The Tail-Wagging Labradors of RESNET

The Best New Blower Door Device You're Gonna Love!

Size Matters — How Big a House Can You Test with One Blower Door?

Are You a Conference Commando? — Advice for RESNET and Beyond

How to Install Flex Duct Properly

The Science of Global Warming Is Older Than Quantum Mechanics

In or Out? Where Does the Paper Facing of Batt Insulation Go?

I Blew a Gasket — Air Leakage at Electrical Switches and Outlets

Surrealistic Home Performance Q&A Inspired By A Chicken

Those Annoying Imperial Units!

Why Do Airtight Homes Need Mechanical Ventilation?

A Blower Door Can't Tell You How Much Mechanical Ventilation You Need

The REAL Reason We Need Building Science

The Thermal Bridge To Nowhere

7 Reasons to Come to the RESNET Conference This Year

Guest Post: What Causes Ice Dams and Icicles?

Should Your Business Have a Blog and Use Social Media?

Residential Ventilation Smackdown — The Battle Over Simplicity

A Ventless Gas Fireplace Is a Liability

A Humidifier Is a Bandaid — The Problem Is Infiltration

Forget the People — A Home Energy Rating Is an Asset Label

The 7 Biggest Mistakes That HVAC Contractors Make

The State of Building Science in the Post-Mayan Non-Apocalypse

The Most Orange Articles from the Energy Vanguard Blog in 2012

What's the BTU Output of a Dragon — A Furnace with Wings?

How Can Replacing a Furnace Make You Less Comfortable?

Recirculating Range Hoods — As Effective As Recirculating Toilets

A Day with Professor Straube at the Building Science Experts' Session

Highlights from Joe Lstiburek's 2012 Experts' Session on Spray Foam

Don't Compromise — Get a Low-Level Carbon Monoxide Monitor

Harnessing the Power of Self Delusion to Build a Green Home

Want Bad Air? Put a Heating & Cooling System in Your Attached Garage

Love Is More Important Than Building Science — A Thanksgiving Story

Where Were the Control Freaks!? Suspended Ceilings Are Air Leaks

Why the IEA's 2012 World Energy Outlook Could Be Wrong

Innovative Net Zero — Appalachian State's Solar Decathlon House

The Electricity Multiplier Effect for Home Energy Efficiency

I-Joists, Attached Garages, and the Air Leaks That Poison

Reason #77 for Being in the Home Performance Business — Costumes

My Choice in the 'Building Enclosure' vs. 'Building Envelope' Battle

Review of an Introductory Green Building Textbook

The Haunted House-as-a-System Down the Street

How Do We Get More Diversity in Green Building and Home Performance?

The 3 Rules of Air Sealing

Building Envelope or Building Enclosure: Which Is the Better Term?

Why Does the US Green Building Council Seem So Out of Touch?

Don't Kill Your Air Flow with This Flex Duct Disease

Words That Turn Home Energy Pros Into Building Science Dorks

Habitat for Humanity Leads the Way to Affordable, Green Homes

Why Don't More HVAC Contractors Own Duct Leakage Testers?

ACEEE's 2012 State Energy Efficiency Scorecard Has Your Number

Popular Chain Restaurant in SC Has Ducts That May Be Illegal

Time for a Reality Check on Our 8 Day HERS Rater Training

Fail! — Ignorance of Building Science Is No Excuse

Dr. Joe Lstiburek Surprises Passive House Conference Attendees

Quick Report on the Passive House Conference in Denver

A 20 Year Old Energy Efficient House Goes to Net Zero in Florida

Not All Knowledge Comes from College

Why Is Air Conditioner Capacity Measured in Tons?

A Standout Example of Duct Design...Or Lack Thereof

BCAP Provides Nice Energy Code Resources for 10 Special States

A Good Window Is Still a Poor Wall

The Lesson of the Raining, Dripping, Crying Duct Boots

Sex Advice, Diet Tips, Decorating Ideas, & HVAC Design

A Strange Silence on Dry-Ship R-22 Air Conditioners

What Are the Best Green Building Products?

Don't Be a Baby! It's Time for Your HVAC System to Grow Up!

The Science Behind the Phase-Out of R-22 Air Conditioner Refrigerant

HVAC Secret: An Air Conditioner Loophole the Size of the Ozone Hole

Be a Controlling Building Enclosure Control Freak with Control Layers

Why an Oversized Air Conditioner Is a Bad Idea

US Energy Flows — Inputs and Outputs 1995 to 2010

The Sludge That Kills — Post Mortem of an Air Conditioner

Not All Mini-Split Heat Pumps Are Ductless!

Why Should I Care About the Passive House Program?

Water Loves Cold and Other HVAC Duct Failure Stories

Are HVAC Contractors Using a Business Model That Leads to Ripoffs?

I DO Need Some Stinkin' Building Science Summer Camp!

Don't Do HVAC to Me

The Sixteenth Annual Building Science Summer Camp Has Begun!

This Playground Slide Can Give You a 'Feel' for Building Science

9 Uncommon Tips for Keeping Cool with a Struggling Air Conditioner

Let's Get This Straight — About the Energy Vanguard Blog

Amazing Breakthrough in HVAC System Efficiency and Performance!

How Energy Efficient Is Your Ceiling Fan?

Does a Geothermal Heat Pump Count as a Renewable Energy Source?

Release the Kraken! — The Ductopus Is Bad for Air Conditioning

How to Grade the Installation Quality of Insulation

A Sword through the Ribs of the Building Envelope

Green Curmudgeons, Architects, and Outlawing Batt Insulation

The Easy Way to Convert between Celsius and Fahrenheit

You Don't Need a Vapor Barrier (Probably)

Why I'm Not a Fan of Positive Pressure Mechanical Ventilation

The Deadline Looms for ENERGY STAR Version 3 New Homes

Everything You Ever Wanted to Know about the HERS Index

Two Open Doors to the Attic - A Building Science Nightmare

A Fun Visualization of Air Leakage During a Blower Door Test

A Home Energy Rating Is Not an Award

Two More Scary Indicators of the Peak Oil Problem

Why Do Architects Focus on Art More than Building Science?

Testing for Duct Leakage in a House with an Encapsulated Crawl Space

The 3 Rules of Air Leakage (Plus a Bonus!)

Keep Your Elbow Rigid — A Lesson in Flex Duct Installation

It's Called an Air Conditioner — Not an Air Cooler!

Can Energy Efficiency Programs Stay Ahead of Energy Codes?

We Are the 99% — Design Temperatures & Oversized HVAC Systems

Rain Barrels, Chickens, and Walking the Sustainable Living Talk

Don't Miss This Opportunity if You're Replacing Windows

Asthma and Poor Indoor Air Quality — The Trouble with Homes

3 Ways to Tell if That Contraption Is a Heat Pump or an AC

The Mystery of the Ventilating Dehumidifier

Vapor Retarder? Vapor Barrier? Perms? What the Heck?!

The Pretty Good House, Part 2

This Hole May Be the Biggest Air Leakage Site in Your Home

Mr. Bean Proposes a Radical Change to Energy Codes

A Home Energy Rater Class Is Just the Beginning

Home Performance Flaw #212: Ducts Placed High in the Attic

Historic Preservation and Deep Energy Retrofits — Natural Enemies?

The Cable Guy Did It! — Attic Insulation Gone Awry

Why Doesn't Heat Flow Backwards?

US Green Building Council to Require All-Glass LEED Homes

Quick Review of the 2012 Affordable Comfort Conference

Thermal Comfort: Everyone Wants It but Few Know the ASHRAE Standard

How Much Air Leakage in Your Home Is Too Much?

How to Sheathe an Attic Kneewall — And How Not to

GUEST POST: Spray Foam, Infrared Cameras, & the New Big Holes

Rare Grade I Fiberglass Batt Insulation Sighting

A Net Zero Energy Home in Rural Tennessee

The ACI Home Energy Leadership Summit - Big Thinking for Our Industry

Who Wants Daylight Savings Time — and Why?

GUEST POST: Lessons Learned by a Reluctant Owner-Builder

Check Out Our RESNET Conference Presentation on Internet Marketing

What Would a "Pretty Good House" Look Like? Part 1.

Taking the Pulse of the Home Energy Pro Community at RESNET 2012

Passive House Appeals to Home Energy Raters

Send Raters, Guns, and Money – Adding Value with HVAC Design

What's Your Point? — Thoughts on My RESNET Conference Talk

Working with Non-Green Trade Contractors in Building a Green Home

If You Think Thermostat Setbacks Don't Save Energy, You're Wrong!

The Metric System Is for Lovers—A Valentine's Day Manifesto

Who Knew the Stack Effect Could Be So Controversial?

This Winter Is 37% Warmer than 2010-11 (by Heating Degree Days)

An Elderly Couple in Maine Offers to Trade Their Car for Fuel Oil

You Do NOT Talk About Building Science Fight Club

Heat Rises...and Falls — Stack Effect, Air Movement, & Heat Flow

The Architecture 2030 Challenge and US EIA Projections

State of the Union Address Missed the Boat on Energy Efficiency

Energy and Power and Confusion and Consternation

ENERGY STAR Version 3 Is Live! Where Are the HVAC Contractors?

No Duct System Losses by 2050? ACEEE Thinks So!

9 Steps to Becoming a Successful Home Energy Pro

Your HVAC System Is the Faucet; The Building Envelope Is the Cup

Is an Electric Space Heater More Efficient Than Your Gas Furnace?

Will the Independent Home Energy Auditor Become Extinct?

What's Your Energy Ideology?

Happy New Year from the Energy Vanguard Blog!

Energy Vanguard's 25 Ridiculous, Made-up Predictions for 2012

5 Best 'Drives Me Crazy' Articles of 2011 in the Energy Vanguard Blog

The Energy Vanguard Blog's Silliest Articles of 2011

The Energy Vanguard Blog's 14 Most Controversial Articles of 2011

Neighborhood Planning for Energy Savings — Acknowledging the Sun

A Storm Door Is NOT a Wise Home Energy Efficiency Improvement

Simple Roofs Perform Better

Naked People Need Building Science

Bob Vila and the Vent-Free Gas Fireplace — A Sorry State of Affairs

The Mad Housers - Not Your Average Cup of Tea

How Much Extra Will the HVAC Cost for ENERGY STAR Version 3 Homes?

Hydronic Furnace & Tankless Water Heater — A Great Combo!

Fire! — Understanding What's Happening in Your Combustion Appliances

10 Reasons to Buy a Home Energy Audit on Cyber Monday

Don't Let the Turkey Get You Down! Carbon Monoxide Alert

Do You Need an Extreme Home Makeover to Get a Soundproof Home?

Energy Auditor Training: Caveat Emptor

3 Great Sources for Home Energy Videos

U R A ΔT, and Other Building Science Blandishments

Won’t That Stink? — Living in a Green Home with a Composting Toilet

Guardian Building Products Makes the Right Move

Why Is Guardian Building Products Threatening Energy Vanguard?

The 3 Types of Energy Efficiency Losses in Water Heating

Where Does Your State Rank in Energy Efficiency? ACEEE Can Tell You

8 Energy, HVAC, & Building Science Horrors to Scare You on Halloween

Are You a Building Science Geek, Nerd, Dork, or Dweeb?

I Really Want to Try the Nest Thermostat

Do Cardboard Ducts Belong in a LEED Certified Home?

Why Is Fall a Good Time of Year for Window Condensation?

Building Codes Assistance Project — Your Source for Energy Code Info

A Visual Guide to Why Fiberglass Batt Insulation Underperforms

7 Steps to Commissioning a New Home & HVAC System

An Idea to Simplify the ENERGY STAR New Homes Program

How I Learned to Count by Building a Green Home

5 Reasons Bath Fans Have Such Poor Air Flow

Would You Rather Have Low Energy Rates or Low Energy Bills?

Steve Jobs — An Icon for Change

Blower Door Testers Wanted - Scientists and Engineers Preferred

Down the Drain! — Heat Recovery for Your Hot Water

A Canadian Perspective of the HERS Rating Industry

Home Builders, Rev Up Your HERS Index for the Cross Border Challenge

The Most Important Lesson I Learned in Grad School

Batts, Blown, or Sprayed - What’s the Best Attic Insulation?

Has the Long Emergency Begun? Peak Oil and the Economic Downturn

An Air Conditioner Sizing Benchmark for High Performance Homes

Why Can't Every New Home Be a High Performance Home?

Are Radiant Barriers Cost Effective in New Homes?

To Heck with Duct Design! Let's Just Throw the Vents Anywhere

5 Tips for a Winning Home Performance Conference Proposal

Rooms Not Getting Enough Air? This Duct Design Flaw May Be to Blame

10 Things You Should Know about the Energy Efficient Mortgage

Cajuns, Living Down the Bayou, and Peak Oil

Voting Is Open for RESNET 2012 Conference Sessions

Under Construction: ENERGY STAR Version 3 Home in Atlanta, Georgia

On Submarines and Building Science

The Best Books I've Ever Read — On Building Science and Beyond

5 Questions to Ask When Replacing Your Air Conditioner

Navigating the Twilight Zone: The Hidden Flaw in a Zoned Duct System

Changes to ENERGY STAR Version 3 Announced by EPA

Dew Point — A More Meaningful Measure of Humidity?

11 Secrets to Blogging about Building Science (or Any Topic, Really)

Home Energy Rater Training — Our First Year Review

Perhaps the Worst HVAC Duct Idea Ever — The Panned Joist Return

Power Attic Ventilators Banned by New Georgia Energy Code

Mystery of the Peeling Ceiling - A Building Science Whodunit

Radiant Barriers Don't Work with Spray Foam Insulation on Them

There's Radiation in Your Home! - And Building Science Can Help

You're Free to Ignore the Laws of Building Science

Joe Lstiburek Is the Devil!

16 Random Thoughts on the First Day of Building Science Summer Camp

Breathe! - Get Fresh Air into Your Home with ASHRAE 62.2

An Easy Way to Save Money — Let Your Air Conditioner Breathe!

Building Science Blogger Reaches Crazy Milestone on Special Day!

How Accurate Is REM/Rate as an Energy Modeling Tool?

I Use an Air Conditioner Sizing Rule of Thumb!

Oooh, Shiny Stuff! - Radiant Barrier Fundamentals

Air Barrier Sleuthing - Building Envelope Lessons for DET Verifiers

Remodeling? Here Are 7 Reasons Not to Skip the Air-Sealing!

ENERGY STAR Version 3 vs. the HERS Index

Learn the Lingo - Air Conditioning Terminology & Tidbits

What Exactly is Manual S in HVAC Design and Why Is It Important?

Eccentric Lives, Peculiar Notions, & Building Science Absurdities

The Magic of Cold, Part 2 - Intermediate Air Conditioning Principles

The Magic of Cold, Part 1 - How Your Air Conditioner Works

More Insulation or High Efficiency Heating & Cooling System?

HVAC Therapy for Energy Code Flunkees – “It’s Not Your Fault”

Should You Get Your Air Conditioner's Ducts Cleaned?

More Important than Home Energy Efficiency - Location Efficiency

Does Energy Efficiency Drive Home Builders out of Business?

Case Closed: Get Those Air Conditioning Ducts out of the Attic

The Medical Doctor, the HVAC Guy, & the Crawl Space

Does Your Bonus Room Need More Air Conditioning?

Combobulating the Perfect Wall - The Basics of Control Layers

Energy Security - The Best Report You've Never Heard of

Don’t Let Your Attic Suck - Power Attic Ventilators Are a Bad Idea

Don't Set Your Air Conditioner Thermostat Like This

Another Duct System No-No: The Unsupported Butt Joint

What Does Energy Security Look Like?

Energy Independence Is a Fantasy - Let's Focus on Energy Security

ENERGY STAR Version 3 - A Tool for Transformation in HVAC

Why Do Million Dollar Homes Get Cheapo HVAC Systems?

Does It Make Sense to Move the Building Envelope to the Roofline?

How to Install a Branched-Drain Greywater System in a Green Home

An HVAC Company That Thinks Outside the Box, Literally

Confusion & Complexity - Can Green Building Programs Be Simplified?

Oversized AC, Screwed-up Manual J, ENERGY STAR HVAC Tirade!

The Ductless Mini-Split Heat Pump's Big Brother - CITY MULTI

3 Reasons Your Crawl Space Has High Humidity & Grows Stuff

Duct-Free Zone - The Advantages of Mini-Split Heat Pumps

No Carts Before Horses - Design for Energy Efficiency Early

How to Choose a Company to Do a Home Energy Audit

News Flash: Americans Use Less Energy When It Costs More

Where the #@$%& Did THAT Come from?

Combustion Safety Rule #1: Remove Exhaust Gases from House

The Ductopus or the Centipede - Which HVAC Duct System Is Better?

No More "Damn Architects!" - The Case for Integrated Design

Are Freedom and Building Science Incompatible?

Keep Out! - One Place NEVER to Put HVAC System Ducts

How Hard Will It Be for Builders to Meet the New Georgia Energy Code?

Should Flex Duct Be Banned by Green Building Programs?

A Green Home - It's Just Good Design

The Value of Training in Building Science - Another Perspective

ACI 2011 - A Mad Review of THE Home Performance Conference

Kick the Can! - No Recessed Lights in the Building Envelope

The McMansion Penalty in ENERGY STAR Version 3

RESNET Enters into Strategic Alliance with Int'l Jugglers Association

How I Use Twitter - A Social Media How-To for Home Energy Pros

Happy 50th Birthday, Allison Bailes III, You’re Younger Than Dirt!

3 Problems with Fiberglass Batt Insulation in Floors

Common Sense - The Best Green Building Skill in the World

Should Nuclear Energy Be in the Mix of Preferred Energy Sources?

Google SketchUp for Home Energy Raters - Measurements Made Easy

Finding Balance - Heat Pump Heating Load vs. Capacity

Meeting ENERGY STAR’s Water Management Checklist

If You Think ENERGY STAR Version 3 Is Hard...

The 2011 RESNET Building Performance Conference Rocked!

The HERS Rater Community Gathers in Orlando

Declining Oil Discoveries - The Truth Behind Peak Oil

Why Won't the HVAC Industry Do Things Right?

Can a Single CO Reading Really Confirm Combustion Safety?

Getting Loopy - How Homes without Insulation Lose Heat

Unvented Natural Gas Space Heaters Should Be Removed

The First ENERGY STAR Version 3 Class for HERS Raters

ENERGY STAR Version 3 Requires Grade I Insulation

Unicorns and Good Home Performance Retrofits: Two Elusive Critters

The 2 Best Learning Opportunities for Home Energy Auditors

Making Your Home Safer with a Sealed Combustion Closet

3 Problems with Atmospheric Combustion Inside the Building Envelope

Insulation Does NOT Stop Infiltration

A Few Photos from Day 1 of Our HERS Rater Class

How NOT to Use Your Heat Pump Thermostat

Watch Our Energy Efficient Mortgage Webinar

Georgia Energy Code Update - Blower Door Testing & DET Verifiers

What Is Pressure? - Understanding Air Leakage

Heat Pumps and Hydronics – A Great Team for High Performance Homes

Just Say No to Furnaces in High Performance Homes

A Dramatic Illustration of a Compromised Building Envelope

Building Science 101

Why Is the Energy Improvement Mortgage So Lonely?

Architecture Bling is Like a Needle Through a Balloon

Attic Stairs - A Mind-Blowing Hole in Your Building Envelope

Snow on the Roof - The Poor Man's Infrared Camera

Allison A. Bailes III, PhD - Building Science Guru, Juggler, Writer

Helping an Asthmatic HVAC System to Breathe

Possums, Dilbert, & Happy Caulkers - A Building Science Blog's Growth

The Blower Door Man Is Coming to Town

Living with the Sun - Building Science in a Broader Context

How the Heck Does a Heat Pump Get Heat from Cold?!

What IS Heat Anyway? - Building Science Fundamentals

4 Products for Enhancing Air Flow in Dryer Vents

Georgia Rocks! - New Energy Code Requires Blower Door Test

An Easy to Fix Air Flow Problem That Can Save Energy - and Your Life

Cold Interior Walls, Useless Insulation, and Building Science

The Opportunity of ENERGY STAR Version 3 - Teamwork!

Hidden Air Leakage Sites in Your Attic

ENERGY STAR Homes Version 3 - Lowering the HERS Index

Energy Efficient Design: A Golden Opportunity for Architects

November Memories - Building a House with Structural Insulated Panels

Using Building Science to Transform a Damp, Musty Basement

Looking at the Building Science Issues in an Old, Humid Basement

ENERGY STAR Version 3 Train-the-Trainer Class - Day 2

ENERGY STAR Version 3 Train-the-Trainer Class - Day 1

Home Energy Pros - A Unique Social Network

Greening the Residential Remodel - Habitat for Humanity's New Push

And Now, for Something Completely Different...

Clean Energy and Conservation Voters Guide

Halloween in Your Home - Scary Stuff You May Not Want to See

Your Connection to the Blast Furnace - Attic Kneewalls

Heat Pump Water Heaters: A Better Way to Heat Water with Electricity?

The Optimism of Pessimism in the Age of Peak Oil

5 Reasons House Wrap Is Not an Air Barrier

Between In & Out - Where the Interesting Building Science Happens

A Huge Heat Loss Flaw - A Lesson in Energy Efficient Design

How Hot Is Your Roof? - Insulated Rooflines and Shingle Temperature

The Future of HERS Rater Training and Building Science Education?

A High Performance Home is Defined by the Process, Not the Products

It's Not Just the Box - High Efficiency HVAC Includes the Ducts

The Telltale Sign of Infiltration

A Bad Duct System Trumps High Efficiency HVAC Equipment

Heating or Cooling - Which Costs You More?

What's the Payback on Home Energy Efficiency?

The End of the Incandescent Light - A Victory for Energy Conservation

Rats to You, Daniel Bernoulli! - Understanding Air Pressure

The End of Growth - Mathematics & Peak Oil

Understanding HVAC - The Next Step for Energy Auditors

The Combustion Safety Wake-Up Call for an HVAC Guy

Dilbert Needs a Home Energy Rater!

An Incomplete Building Envelope Doesn't Work

The Foil-Faced Bubble Wrap Sham - Understanding Radiant Barriers

HVAC Design Done Right - Manual J, S, T, & D

Know Your Terms - Heat Pump Efficiency Ratings SEER & HSPF

Reducing the Pressure on HERS Rater Class Students

New Training Required for ENERGY STAR Partners

Don't Forget the Science in Building Science

Matt Simmons - Hero of Peak Oil Awareness

It's the Hole - Understanding What a Blower Door Is for

Infiltration Occurs at the Surface, Not in the Volume

I Don't Need No Stinkin' Building Science Summer Camp!

Mike Barcik - A Stellar Advocate for the Georgia Energy Code

The Groundbreaking New Georgia State Energy Code

Questions to Ask before You Take a Home Energy Rater Class

How to Choose a HERS Rater Training Class

Green Building in Florida- My Southeast Building Conference Wrapup

Energy Efficient Design for Green Modular Homes

Turn Off That Dehumidifier!

A Little Self Promotion about Our HERS Provider Services

Photo Friday - HVAC Filter Horrors

Mind the Gap - Air Leakage at the Top Plates

Do Power Factor Correction Devices Save Energy?

Is the HERS Rater Test Too Difficult?

Is HERS Rater Training a Scam?

Window Condensation - Moisture Problems & Energy Conservation

A New Idea for HVAC Contractors

Energy Vanguard is Now a HERS Rater Training Provider!

The 'Not So Big House' and Energy Efficient Design

Got Manual J? Don't Assume It's Correct.

4 Pitfalls of Spray Foam Insulation

Flat or Lumpy - How Would You Like Your Insulation?

Turn Off Those Ceiling Fans!

Green Modular Homes Defy Stereotypes

Does a High Performance Home Have to Look Weird?

Home Star Energy Retrofit Act Update

A Day in the Life of a HERS Provider

How to Tell If You Have an Oversized Air Conditioner

The Silent Heroes of Energy Efficient Design

The REAL Tragedy of the Oil Industry in Louisiana

My 6 Favorite Sources for Building Science & Green Building Info

The 4 Factors of Comfort

Designed to Earn the ENERGY STAR, Our First Design Project

Creativity, Education, and Green Jobs

5 Keys to Success in Education for Green Jobs

More Energy Saving Dogs from Georgia Power

Myth: A House Needs to Breathe

EEM Update - My Friend Perry's New Home

Little Shop of Duct Design Horrors

Energy Efficiency Versus Energy Conservation

An Oversized Cooling System Isn't Always a Bad Thing

Home Energy Rater Training - A New Approach

Is Building a Green Home Better Than Renovating an Old Home?

The Problem of Pirates and Home Energy Audits

Georgia Energy Code Pushes the Envelope...Literally

A Perfect Candidate for an EEM

Builder Pays Extra for Oversized Cooling Systems

ENERGY STAR 2011 - Version 3 of the New Homes Program

The Only Two Certifications for Home Energy Auditors

What Do Eggs Have to Do with Energy Conservation?

Home Star Rebate Program Gains Momentum

ENERGY STAR Trained Dogs Find Energy Savings

5 Step Program for Solar Energy

Finding Air Leaks with a Wizard Stick

Beware of Home Energy Auditor Certification Scams

The Four Types of Duct Leakage

When Is 100% Efficient Not Good Enough?

5 Myths about Home Energy Efficiency

An Energy Efficient Mortgage (EEM) Bonanza

Vented Crawl Spaces: Some Common Problems

Energy Efficient Mortgage Presentation at RESNET Conference

What's Your Home Energy Efficiency Number?

Cash for Caulkers

Don't Insulate Your Attic!

Energy Vanguard Rater Howard Feldman Meets President Obama!

Peak Oil, Financial Chaos, and Homes