FHB Logo Facebook LinkedIn Email Pinterest Twitter X Instagram Tiktok YouTube Plus Icon Close Icon Navigation Search Icon Navigation Search Icon Arrow Down Icon Video Guide Icon Article Guide Icon Modal Close Icon Guide Search Icon Skip to content
Subscribe
Log In
  • How-To
  • Design
  • Tools & Materials
  • Restoration
  • Videos
  • Blogs
  • Forum
  • Magazine
  • Members
  • FHB House
  • Podcast
Log In
Ask the Experts

Envelope Vs. Enclosure?

The building enclosure includes four control layers, which may be separate or close together depending on the assembly.

By Kohta Ueno Issue 323 - June 2024
  • X
  • facebook
  • linkedin
  • pinterest
  • email
  • add to favorites Log in or Sign up to save your favorite articles
Drawing bu Martha Garstang Hill, adapted from John Straube.

Is there a difference between the terms “building envelope” and “building enclosure”? They seem to be used interchangeably in the building community, but do they mean the same thing?

—Samantha Maver; Trumbull, Conn.

Kohta Ueno, principal engineer at Building Science Corp., replies: “Building envelope” and “building enclosure” are currently used synonymously, but “building enclosure” is the more up-to-date term. Both describe the part of the building (above grade or below grade) that physically separates the interior environment from the exterior environment. Therefore, walls, roofs, foundations, floor assemblies, and glazing typically make up the building enclosure.

Let’s Dive Deeper

The terminology “building enclosure” comes from Eric Burnett, a professor who has educated and influenced an entire generation of building scientists in North America, including both of my mentors, Joe Lstiburek and John Straube. Professor Burnett is a stickler for exactness; one of his points is that historically, “building envelope” has not included the below-grade enclosure, which definitely separates interior from exterior. His common refrain is, “You put letters in an envelope, and you put people in an enclosure.”

I can’t say that I completely understand the semantics, but out of deference to “Dr. B.” (who has thought far more about this topic), I always use “building enclosure” … although I still understand “building envelope.” Also, many of the technical bodies such as ASHRAE and the Building Enclosure Councils have switched to “building enclosure.” The takeaway: Use “building enclosure” if you want to sit at the big kids’ table.

On modern houses built to code, the building enclosure will include four principal control layers: a water control layer, an air control layer, a vapor control layer, and a thermal control layer. These jobs can be split up among multiple materials, or be combined in one.

More to Keep in Mind

The International Residential Code, in the section on energy efficiency, uses the term “building thermal envelope,” which refers to the location of the thermal control (insulation) layer. Therefore, the thermal envelope may be within the boundary of the building enclosure—for example, imagine a ventilated attic, where insulation is at the floor of the attic space. Taped drywall with air-sealed penetrations on the ceiling provides air and vapor control, preventing air and vapor leakage from conditioned space to the ventilated attic.

Loose-fill insulation on top of the drywall provides thermal control. The ventilated air space of the attic also provides vapor control: interior-to-exterior moisture leakage into the attic is “ventilated away” before condensing on cold surfaces. And lastly, water control is provided by the shingles and underlayment on the roof sheathing.

When combined, the four control layers make up the building enclosure—so while some control layers are at the ceiling, the entire ventilated attic space is part of the building enclosure.

Need Help?

Need help with issues like figuring out the difference between building envelope vs. building enclosure? Get answers you can trust from the experienced pros at FHB. Email your question to [email protected].

From Fine Homebuilding #323

RELATED STORIES

  • Evolving an Energy-Efficient Envelope
  • FHB House Video: The Building Envelope
  • Podcast 601: Envelope Leaks, Rebuilding a Cabin, and Adding Water to Hydronic Heat

Fine Homebuilding Recommended Products

Fine Homebuilding receives a commission for items purchased through links on this site, including Amazon Associates and other affiliate advertising programs.

Insulation Knife

If you like insulating with mineral wool, this knife makes cuts that are clean, neat, and easy — it's much better than a utility knife which can be slow and messy.
Buy at Amazon

Disposable Suit

This suit provides full body protection to help you stay clean from head to toe when installing insulation. We recommend wearing sweats underneath for additional coverage.
Buy at Amazon

Great Stuff Foam Cleaner

It’s important to clean and maintain a professional foam-dispensing gun, and this product fits the bill. It has a spray applicator for general cleaning, plus it screws onto the dispensing gun so you can clean the inside.
Buy at Amazon

Sign up for eletters today and get the latest how-to from Fine Homebuilding, plus special offers.

Signing you up...

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
See all newsletters
See all newsletters
×

Get home building tips, offers, and expert advice in your inbox

Signing you up...

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
See all newsletters
See all newsletters

New Feature

Fine Homebuilding Forums

Ask questions, offer advice, and share your work

  • X
  • facebook
  • linkedin
  • pinterest
  • email
  • add to favorites Log in or Sign up to save your favorite articles

Log in or create an account to post a comment.

Sign up Log in

Become a member and get full access to FineHomebuilding.com

More Ask the Experts

View All
  • Installing Prefinished Cabinet Molding
  • Tall Deck on a Sloped Lot
  • Hard-to-Use Electrical Outlets
  • HVAC for a Slab-on-Grade House
View All

Up Next

Video Shorts

Featured Story

FHB Podcast Segment: Sometimes Spray Foam Makes Sense, Sometimes It Doesn't

Spray foam is a great invention, but it's not always necessary.

Featured Video

Micro-Adjust Deck-Baluster Spacing for an Eye-Deceiving Layout

No math, no measuring—just a simple jig made from an elastic band is all you need to lay out a good-looking deck railing.

Related Stories

  • FHB Podcast Segment: Sometimes Spray Foam Makes Sense, Sometimes It Doesn't
  • All About Continuous Insulation
  • A Practical Approach to Exterior Insulation
  • FHB Podcast Segment: Designing and Building an Efficient Slab-On-Grade Home

Discussion Forum

Recent Posts and Replies

  • |
  • |
  • |
  • |
  • |
  • |
View More Create Post

Highlights

Fine Homebuilding All Access
Fine Homebuilding Podcast
Tool Tech
Plus, get an extra 20% off with code GIFT20

Video

View All Videos
  • FHB Podcast Segment: Insulating the Roof of a Small Balloon-Framed House
  • FHB Podcast Segment: Old Home Insulation Troubles - How to Find the Right Contractor
  • FHB Podcast Segment: Is There a 'Right' Spot for a Vapor Retarder in this Climate Zone?
  • FHB Podcast Segment: Ductwork in a Vented Attic
View All

Attics

View All Attics Articles
  • HVAC for a Slab-on-Grade House
  • Strategies for Making an Old House Airtight
  • Podcast Episode 649: Sealing Crawlspaces, Problem Porches, and AC in Attics
View All Attics Articles

Fine Homebuilding Magazine

  • Issue 331 - June 2025
    • A More Resilient Roof
    • Tool Test: You Need a Drywall Sander
    • Ducted vs. Ductless Heat Pumps
  • Issue 330 - April/May 2025
    • Deck Details for Durability
    • FAQs on HPWHs
    • 10 Tips for a Long-Lasting Paint Job
  • Issue 329 - Feb/Mar 2025
    • Smart Foundation for a Small Addition
    • A Kominka Comes West
    • Making Small Kitchens Work
  • Issue 328 - Dec/Jan 2024
    • How a Pro Replaces Columns
    • Passive House 3.0
    • Tool Test: Compact Line Lasers
  • Issue 327 - November 2024
    • Repairing Damaged Walls and Ceilings
    • Plumbing Protection
    • Talking Shop

Fine Home Building

Newsletter Sign-up

  • Fine Homebuilding

    Home building tips, offers, and expert advice in your inbox.

  • Green Building Advisor

    Building science and energy efficiency advice, plus special offers, in your inbox.

  • Old House Journal

    Repair, renovation, and restoration tips, plus special offers, in your inbox.

Signing you up...

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
See all newsletters

Follow

  • Fine Homebuilding

    Dig into cutting-edge approaches and decades of proven solutions with total access to our experts and tradespeople.

    Start Free Trial Now
    • Facebook
    • Instagram
    • X
    • LinkedIn
  • GBA Prime

    Get instant access to the latest developments in green building, research, and reports from the field.

    Start Free Trial Now
    • Facebook
    • YouTube
  • Old House Journal

    Learn how to restore, repair, update, and decorate your home.

    Subscribe Now
    • Facebook
    • Instagram
    • X
  • Fine Homebuilding

    Dig into cutting-edge approaches and decades of proven solutions with total access to our experts and tradespeople.

    Start Free Trial Now
    • Facebook
    • Instagram
    • X
    • LinkedIn
  • GBA Prime

    Get instant access to the latest developments in green building, research, and reports from the field.

    Start Free Trial Now
    • Facebook
    • YouTube
  • Old House Journal

    Learn how to restore, repair, update, and decorate your home.

    Subscribe Now
    • Facebook
    • Instagram
    • X

Membership & Magazine

  • Online Archive
  • Start Free Trial
  • Magazine Subscription
  • Magazine Renewal
  • Gift a Subscription
  • Customer Support
  • Privacy Preferences
  • About
  • Contact
  • Advertise
  • Careers
  • Terms of Use
  • Site Map
  • Do not sell or share my information
  • Privacy Policy
  • Accessibility
  • California Privacy Rights

© 2025 Active Interest Media. All rights reserved.

Fine Homebuilding receives a commission for items purchased through links on this site, including Amazon Associates and other affiliate advertising programs.

  • Home Group
  • Antique Trader
  • Arts & Crafts Homes
  • Bank Note Reporter
  • Cabin Life
  • Cuisine at Home
  • Fine Gardening
  • Fine Woodworking
  • Green Building Advisor
  • Garden Gate
  • Horticulture
  • Keep Craft Alive
  • Log Home Living
  • Military Trader/Vehicles
  • Numismatic News
  • Numismaster
  • Old Cars Weekly
  • Old House Journal
  • Period Homes
  • Popular Woodworking
  • Script
  • ShopNotes
  • Sports Collectors Digest
  • Threads
  • Timber Home Living
  • Traditional Building
  • Woodsmith
  • World Coin News
  • Writer's Digest
Active Interest Media logo
X
X
This is a dialog window which overlays the main content of the page. The modal window is a 'site map' of the most critical areas of the site. Pressing the Escape (ESC) button will close the modal and bring you back to where you were on the page.

Main Menu

  • How-To
  • Design
  • Tools & Materials
  • Video
  • Blogs
  • Forum
  • Project Guides
  • Reader Projects
  • Magazine
  • Members
  • FHB House

Podcasts

  • FHB Podcast
  • ProTalk

Webinars

  • Upcoming and On-Demand

Podcasts

  • FHB Podcast
  • ProTalk

Webinars

  • Upcoming and On-Demand

Popular Topics

  • Kitchens
  • Business
  • Bedrooms
  • Roofs
  • Architecture and Design
  • Green Building
  • Decks
  • Framing
  • Safety
  • Remodeling
  • Bathrooms
  • Windows
  • Tilework
  • Ceilings
  • HVAC

Magazine

  • Current Issue
  • Past Issues
  • Magazine Index
  • Subscribe
  • Online Archive
  • Author Guidelines

All Access

  • Member Home
  • Start Free Trial
  • Gift Membership

Online Learning

  • Courses
  • Project Guides
  • Reader Projects
  • Podcast

More

  • FHB Ambassadors
  • FHB House
  • Customer Support

Account

  • Log In
  • Join

Newsletter

Get home building tips, offers, and expert advice in your inbox

Signing you up...

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
See all newsletters
See all newsletters

Follow

  • X
  • YouTube
  • instagram
  • facebook
  • pinterest
  • Tiktok

Join All Access

Become a member and get instant access to thousands of videos, how-tos, tool reviews, and design features.

Start Your Free Trial

Subscribe

FHB Magazine

Start your subscription today and save up to 70%

Subscribe

We hope you’ve enjoyed your free articles. To keep reading, become a member today.

Get complete site access to expert advice, how-to videos, Code Check, and more, plus the print magazine.

Start your FREE trial

Already a member? Log in

Privacy Policy Update

We use cookies, pixels, script and other tracking technologies to analyze and improve our service, to improve and personalize content, and for advertising to you. We also share information about your use of our site with third-party social media, advertising and analytics partners. You can view our Privacy Policy here and our Terms of Use here.

Cookies

Analytics

These cookies help us track site metrics to improve our sites and provide a better user experience.

Advertising/Social Media

These cookies are used to serve advertisements aligned with your interests.

Essential

These cookies are required to provide basic functions like page navigation and access to secure areas of the website.

Delete My Data

Delete all cookies and associated data