Outdoor Living

Granny Flats to Guest Houses: ADUs are a Hot Commodity

Bigger isn’t always better 😉 Accessory Dwelling Units, or ADUs, are proof positive that great things do indeed come in small packages. So what the heck is an ADU you ask? Well, simply put, an ADU can be a small outbuilding on the same property as a single-family home that can function as anything from a guest house, granny flat, art studio, home office, you name it. Renovated basements that become separate apartment homes, though, are also considered ADUs. Depending on the state and municipality, typical ADUs can range from 600 square feet up to 1,200 square feet. They can be used by the owner of the main house or rented out. Some ADUs even have a completely different ownership.

Despite their recent rise in popularity, ADUs are not a particularly new concept, just a modern spin on the carriage house or even “pool house that doubles as a guest house” concept. The need for affordable housing, population density and multigenerational living are just a few of the reasons that ADUs are so hot right now. And with local governments getting on board with the ADU trend, it’s becoming easier for homeowners to build and rent out ADUs.

While I was preparing this blog for you today, I came across so many awesome ADUs that I wanted to share. Here are some of my favorites.



For those of you who follow Marcia Moore Design on Instagram and/or Facebook (and if you don’t, please do), you’ll recognize this first ADU, a beautiful red barn reimagined by architect Christopher Strom. Winner of the 2017 Marvin Windows and Doors Architects Challenge for Contemporary Design, this compact cutie has been featured in numerous publications celebrating the joys of living big in a small space.

Created as a separate accommodation for the client’s visiting family, friends and guests, the design for this transitional remodel/addition is reminiscent of a traditional red barn in form and color and just 380 square feet. Strom’s strategic use of glass and volume, however, creates a bright, dramatic space that belies its tiny size.

This adorable guest house was built in 1820 and is located in the heart of Beaufort, South Carolina’s, historic district.

A courtyard separates the guest house from the main house of this California property.

Architectural Design by Steven Erlich | Photo by Erhard Pfeiffer | Architectural Digest


(photo left) At designer Suzanne Kasler’s Atlanta home, the first floor of the guest house serves as a garage.

(photo right) At film producer Steve Tisch’s refined yet relaxed Beverly Hills home, the neo-Regency pool house, also functions as the guest quarters.

Architectural Design by William T. Baker | Photo by Pieter Estersohn | Architectural Digest


Architectural Design by Appleton & Associates | Photo by Roger Davies | Architectural Digest


(photo left) For a client’s guest house and studio/library on the Nevada side of Lake Tahoe, architect Roderick Ashley designed two pavilions. A marble-and-steel sculpture by the project’s landscape architect, Robert Murase, and his son Scott, leads to the guest house.

(photo right)  Floor plans are available through Yankee Barn Homes to build this neo-Victorian-inspired post and beam frame carriage house, which packs a lot of punch into its 1,142 square feet of living space.

Architectural Design by Roderick Ashley | Landscape Design by Robert Murase Photo by Mary E. Nichols | Architectural Digest


Designer Allison Elebash transformed her garage into a happy, sunny guest house in Charleston, South Carolina. Inside the home, a color palette of lemonade yellow, swimming pool aqua, and the warm ivory of homemade vanilla ice cream creates a home that always feels like summer.

DID YOU KNOW? ADU vs. Tiny House

No doubt you’ve heard of The Tiny House Movement. This trend is actually a social movement which embraces downsizing, simplifying and living with less. There are even TV shows, such as HGTV’s “Tiny House Big Living,” that celebrate this lifestyle.

But what’s the difference between a “Tiny House” and an “ADU?”

Basically, they’re very similar, although many tiny houses are on wheels so they can be moved when the urge strikes. And typically, tiny houses are much smaller (some as little as 200 square feet) than ADUs.



Guest houses are great, but many ADUs serve as a primary residence. Building an ADU on your property can be a great solution if you have senior family members who want the independence of living alone with the security of having you nearby. Cue the “granny flat.” Or what about “boomerang kids?” Those adult children who have graduated college but are looking for a way to save money while paying down educational debt? An ADU can get help them get on their feet, but not under your roof.

Aging homeowners might consider building an ADU to accommodate a live-in caretaker, housekeeper or gardener. An ADU can also be an enticing and affordable option for those who wish to be less trapped by house debt, allowing them the freedom to make lifestyle choices that might not be possible with a big mortgage or rent payment. And with Airbnb and VRBO so popular these days, a welcoming ADU can become an extra source of income for homeowners.

Here are a few ADUs that have “home sweet home” written all over them.


This gorgeous carriage house is one of Arthur Miller’s four Brooklyn residences. He lived here in the 1950s until he left to marry Marilyn Monroe. The house is located in the Brooklyn Heights Historic District and is on the National Register of Historic Places.

Photo by Steve Minor


With its arched garage doors, shake siding, and decorated gables, this classic carriage house is full of character. The depth of the garage provides enough space for additional storage or a hobby shop.

If a traditional carriage house or cottage is not your style, take a look at these awesome contemporary ADUs.

Traditional or contemporary, the Granny Flat (no, it’s not a shoe), is perfectly sized and not just for grannies. This ADU can be a great option for a young adult or couple, empty nesters or even someone who just doesn’t want a lot of space or a big mortgage.





Did you Know? An ADU by any other name…is still an ADU.

Here are some of the terms you might have heard:

  • accessory apartment
  • alley flat
  • granny flat
  • granny pod
  • back house
  • backyard bungalow
  • carriage house
  • coach house
  • garage apartment
  • guest house or cottage
  • in-law suite
  • laneway house
  • mother-daughter house
  • multigenerational house
  • ohana unit
  • secondary dwelling
  • sidekick



Second verse better than the first

Reimagining an existing outbuilding into something brand new can be really fun and gives you the opportunity to have a space you might not otherwise have thought possible. Here are a few “redos” that really rock.

Working from home but no real office space in your residence? Maybe an ADU office is the answer!

This office is made from a shipping container!



This two-story house is actually one shipping container on top of the other.

A work-at-home couple took down a dilapidated garage in their North Portland backyard to build a guesthouse they use as an office and for friends, Airbnb guests and community workshops.

For the book lover! A reading retreat right in your own backyard.

Maybe it’s a creative getaway that you would love to have; an art studio maybe?

Think silos are just for storing hay and grain. Think again. The industrial-chic look of the steel structures are making some people look at silos in a whole new light.

(photo left) This silo-turned-party barn is part of the extensive renovation of an antebellum Virginia Homestead.

(photo right) Architect Christoph Kaiser bought a 1955 grain silo from a Kansas farmer over the internet. He then converted the steel structor into a cozy studio for him and his wife.

Did You Know? These ADUs were made famous on TV and in the movies.

Recognize these ADUs?

(photo left) When the Cunninghams think their hardware store is doomed, they decide to rent out the apartment above their garage for $50 a month to Arthur Fonzerelli in the 1970s sitcom Happy Days.

(photo right) It’s a small house in contrast to Gatsby’s enormous mansion, but it’s the perfect place for a writer Nick Carraway to spend the summer in The Great Gatsby.

And finally, here are two out of this world ADUs that just take your breath away…architectural marvels that are just amazing.

(first two photos) This sculptural backyard structure is made from wood panels that curve around each other to create a backyard office as well as a storage space for extra garden things.

(rest of photos) A large shell shaped structure finds itself in the middle of the woods. It is hard to determine what exactly the structure is, and unlike the surrounding caves and rocks, it clearly is not a part of nature – nor is it a ruin. A frame, a shape, made at a completely different place for a completely different purpose. Within this shell-shaped structure  one will find floors constructed, walls separating spaces, and rooms furnished. The scenery conjures a sci-fi film-like image, in which locals an abandoned spacecraft. With time, trees start to grow encircling the spacecraft, harmonizing it into the landscape. (Arch Daily)

For more photos of this amazing home, CLICK HERE.


So what do you think? Is an ADU calling your name? We’re back running full speed at Marcia Moore Design and would so love to help you create a special space all your own. If you’d still prefer to work virtually, we understand and can do that, too. Whatever works best for you and makes you the most comfortable is great with us. Give us a call at 314.395.1114 or CLICK HERE to send us an email.

Stay safe and healthy,

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P.P.S. CLICK HERE to check out our portfolio. We recently uploaded several new projects that we’re super excited about.


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