See an Eco-Friendly Backyard Cottage in 700 Square Feet
In this video, watch how a green builder helps a Seattle couple create an energy-efficient home inspired by Houzz photos
Mitchell Parker
13 March 2021
Houzz Editorial Staff. Home design journalist writing about cool spaces, innovative trends, breaking news, industry analysis and humor.
Houzz Editorial Staff. Home design journalist writing about cool spaces, innovative... More
Anna and Donovan Watt had planned to build a studio rental apartment over a new garage in the backyard of their recently purchased four-bedroom home outside Seattle. But after they met with green builder Sean Conta, their vision changed. Conta showed the Watts that they could build a 700-square-foot, two-bedroom backyard cottage within their budget using efficient and sustainable building practices. “It made us start to think we can actually live in this versus [just using it] as a rental for somebody else,” Donovan says.
Once they saw Conta’s renderings of the proposed cottage, the Watts decided to build the cottage — with inspiration from Houzz photos — move into it and rent out the four-bedroom house instead.
Once they saw Conta’s renderings of the proposed cottage, the Watts decided to build the cottage — with inspiration from Houzz photos — move into it and rent out the four-bedroom house instead.
Photos by Jesse Young
House at a Glance
Who lives here: Anna Watt, a project manager and community manager in the tech industry; her husband, Donovan, a video game animator; their miniature Australian Shepherd, River; and their cat, Lambert
Location: Shoreline, Washington
Size: 700 square feet (65 square meters), plus a 200-square-foot (19-square-meter) deck
Builder: Sean Conta of Targa Homes
In 2017, the Watts moved to Shoreline from the San Francisco Bay Area, where they had been priced out of their dream of owning a single-family home. Anna has family around Puget Sound in Washington state, and Donovan has family in Vancouver, about a 2½-hour drive north of Shoreline, so the area made sense for the couple, who also love the outdoor activities in the area, such as fishing for salmon and crabbing. Plus, they liked the large, flat quarter-acre lots in the suburban neighborhood.
After they bought and moved into their four-bedroom home, they had conversations with Conta for about a year regarding the backyard cottage design. Conta had spent five years in the green-building-certification industry, assessing projects to verify that they followed green-building-certification requirements, and he also had worked as a consultant to other builders on how to build green homes. When he met the Watts, he was just starting his own green-building firm, and the Watts became his first clients.
Conta framed the house using 90 percent reclaimed lumber and set the foundation on 23 Diamond Pier footings, a type of pin-pile construction that elevates the house a few feet off the ground. He did the latter for several reasons. It’s a little cheaper and faster to build this type of construction versus a traditional concrete slab foundation, and it was something he could build himself (he did it in six days) with very low impact to the site. “There was no excavation or digging, so no disruption of the hydrology of the soil,” he says.
Watch now: Go inside this eco-friendly backyard cottage in the latest episode of Houzz TV
House at a Glance
Who lives here: Anna Watt, a project manager and community manager in the tech industry; her husband, Donovan, a video game animator; their miniature Australian Shepherd, River; and their cat, Lambert
Location: Shoreline, Washington
Size: 700 square feet (65 square meters), plus a 200-square-foot (19-square-meter) deck
Builder: Sean Conta of Targa Homes
In 2017, the Watts moved to Shoreline from the San Francisco Bay Area, where they had been priced out of their dream of owning a single-family home. Anna has family around Puget Sound in Washington state, and Donovan has family in Vancouver, about a 2½-hour drive north of Shoreline, so the area made sense for the couple, who also love the outdoor activities in the area, such as fishing for salmon and crabbing. Plus, they liked the large, flat quarter-acre lots in the suburban neighborhood.
After they bought and moved into their four-bedroom home, they had conversations with Conta for about a year regarding the backyard cottage design. Conta had spent five years in the green-building-certification industry, assessing projects to verify that they followed green-building-certification requirements, and he also had worked as a consultant to other builders on how to build green homes. When he met the Watts, he was just starting his own green-building firm, and the Watts became his first clients.
Conta framed the house using 90 percent reclaimed lumber and set the foundation on 23 Diamond Pier footings, a type of pin-pile construction that elevates the house a few feet off the ground. He did the latter for several reasons. It’s a little cheaper and faster to build this type of construction versus a traditional concrete slab foundation, and it was something he could build himself (he did it in six days) with very low impact to the site. “There was no excavation or digging, so no disruption of the hydrology of the soil,” he says.
Watch now: Go inside this eco-friendly backyard cottage in the latest episode of Houzz TV
The Watts gave Conta full creative license on the design and building aspects, while Anna spearheaded a lot of the decisions on paint colors, tile and furniture. She used Houzz photos to gather inspiration. For example, Anna used this photo by DeForest Architects to inspire the look of the exterior, which is 100-year-old reclaimed fir wood and fiber cement siding (HardiePlank) painted gray.
Anna found the gray paint color by looking through questions posted to the photo uploaded to Houzz. DeForest Architects had responded to a question about the paint color on the exterior of the home in the photo, mentioning Knoxville Gray by Benjamin Moore.
Anna bought a sample of that color, and Conta painted a test square on the HardiePanels. Anna gave the thumbs-up. Conta then eyeballed the stain of the wood in the photo to get the honey color eventually used on the cottage. “I could not have brought this house to life without the Houzz platform,” Anna says. “I’m a visual learner.”
One major change to the design came two days before Conta pulled permits for the project. One morning, Anna stepped outside her main home, coffee in hand, and walked to the area in the yard that had been roped off to show where and how the rooms in the future cottage would be arranged. She stood in what was then the planned entryway and realized the morning sunlight would be perfect for the kitchen, which at the time was on the opposite side. She immediately emailed Conta and told him she wanted to flip the floor plan. “I always said I would never be that client,” Anna says. “I’m a project manager. I know what it costs emotionally and literally to redo things. But having that morning sunlight in the kitchen made more sense.”
Without hesitation, Conta reached out to John Benavente, the architectural designer for the project, and modified the plan to flip the layout before submitting it to the city for permits.
Find a homebuilder near you
Anna found the gray paint color by looking through questions posted to the photo uploaded to Houzz. DeForest Architects had responded to a question about the paint color on the exterior of the home in the photo, mentioning Knoxville Gray by Benjamin Moore.
Anna bought a sample of that color, and Conta painted a test square on the HardiePanels. Anna gave the thumbs-up. Conta then eyeballed the stain of the wood in the photo to get the honey color eventually used on the cottage. “I could not have brought this house to life without the Houzz platform,” Anna says. “I’m a visual learner.”
One major change to the design came two days before Conta pulled permits for the project. One morning, Anna stepped outside her main home, coffee in hand, and walked to the area in the yard that had been roped off to show where and how the rooms in the future cottage would be arranged. She stood in what was then the planned entryway and realized the morning sunlight would be perfect for the kitchen, which at the time was on the opposite side. She immediately emailed Conta and told him she wanted to flip the floor plan. “I always said I would never be that client,” Anna says. “I’m a project manager. I know what it costs emotionally and literally to redo things. But having that morning sunlight in the kitchen made more sense.”
Without hesitation, Conta reached out to John Benavente, the architectural designer for the project, and modified the plan to flip the layout before submitting it to the city for permits.
Find a homebuilder near you
The front door opens into a small entryway. Anna chose a pendant light that visually obscures the mini-split heating unit on the wall behind it while still allowing air to flow through. “Plus it looks great next to the wood wall,” she says of the pendant.
The same reclaimed-wood siding used on the exterior is wrapped around the entryway to cover the wall behind the TV. “It looks like a column of wood that’s supposed to be there,” Anna says. “We kept the same stain as the outside so it felt like the exterior is coming in naturally. It’s now my favorite part of the home. It really warms up the space. And it feels good to reuse 100-year-old wood that would have otherwise gone to waste.”
Mirror: Mira in natural, Umbra; pendant: Infinity wicker sphere in rustic brown, KOUBOO
The same reclaimed-wood siding used on the exterior is wrapped around the entryway to cover the wall behind the TV. “It looks like a column of wood that’s supposed to be there,” Anna says. “We kept the same stain as the outside so it felt like the exterior is coming in naturally. It’s now my favorite part of the home. It really warms up the space. And it feels good to reuse 100-year-old wood that would have otherwise gone to waste.”
Mirror: Mira in natural, Umbra; pendant: Infinity wicker sphere in rustic brown, KOUBOO
The living room is narrow and long, and Anna chose a sofa that fits proportionally, looks good, offers plenty of seating and includes a pullout bed for overnight guests. Here, River, a 35-pound Australian shepherd, lies on the couple’s new rug.
Conta put windows mostly at or above eye level (including near the 13-foot-high ceiling) to bring in natural light while allowing for a bit of privacy from the main house at the front of the lot. “It makes a huge difference in a small space,” Anna says.
The Watts also added frosted-glass windows to the rear of the main house before they moved into the cottage.
Sofa: Melrose reversible chaise sleeper in silver, Apt2B; rug: Loren collection in terra cotta and blue, Loloi Rugs; coffee table: modern round in white marble, Walker Edison; pouf: Zona, Kosas
Watch now: See more of this charming home built using green building methods
Conta put windows mostly at or above eye level (including near the 13-foot-high ceiling) to bring in natural light while allowing for a bit of privacy from the main house at the front of the lot. “It makes a huge difference in a small space,” Anna says.
The Watts also added frosted-glass windows to the rear of the main house before they moved into the cottage.
Sofa: Melrose reversible chaise sleeper in silver, Apt2B; rug: Loren collection in terra cotta and blue, Loloi Rugs; coffee table: modern round in white marble, Walker Edison; pouf: Zona, Kosas
Watch now: See more of this charming home built using green building methods
To maximize square footage, Conta skipped adding hallways inside the home. Donovan uses the bedroom through the door on the right seen here as his home office for his work as a video game animator. The middle door opens to a full bathroom. The couple’s bedroom is through the door at the far left, near the kitchen.
Conta built the home to have an airtight envelope, which means heat doesn’t escape through cracks from poorly constructed framing and cold air doesn’t leak in. This allows for efficiency in heating the home, because a heating unit doesn’t need to constantly be run to make up for lost heat going out.
An energy recovery ventilator, or ERV, pulls stale air out of the house, recovers the heat from that outgoing air and transfers it to incoming filtered air. This means the air coming in is clean and already at a temperature of, say, 65 degrees when it enters the house. And that means the mini-split heating unit doesn’t have to spend as much energy heating air to a comfortable 70-degree indoor temperature as it would if it were attempting to heat incoming air that’s at the temperature of a chilly 45-degree Seattle day, for example.
“It’s very airtight, and there’s a continual supply of fresh, filtered air 24 hours a day,” Conta says. “We get forest fires up here, so on a supersmoky day, the air inside this house is much cleaner than [in] the average house.”
The building shell is also superinsulated. If you were to look at a cross section of the house’s main walls, you would see the layers from the interior of the home to the exterior: Sheetrock, blown-in fiberglass insulation between 2-by-4-inch reclaimed studs, 4-by-8-foot sheets of plywood sheathing, a water-resistant barrier (WRB), 2 inches of mineral wool board, 1-by-4-inch rain screen strips, and then the exterior siding (either reclaimed wood or fiber cement, depending on which wall). “The mineral wool board is sort of like a wool sweater for the house,” Conta says.
Conta built the home to have an airtight envelope, which means heat doesn’t escape through cracks from poorly constructed framing and cold air doesn’t leak in. This allows for efficiency in heating the home, because a heating unit doesn’t need to constantly be run to make up for lost heat going out.
An energy recovery ventilator, or ERV, pulls stale air out of the house, recovers the heat from that outgoing air and transfers it to incoming filtered air. This means the air coming in is clean and already at a temperature of, say, 65 degrees when it enters the house. And that means the mini-split heating unit doesn’t have to spend as much energy heating air to a comfortable 70-degree indoor temperature as it would if it were attempting to heat incoming air that’s at the temperature of a chilly 45-degree Seattle day, for example.
“It’s very airtight, and there’s a continual supply of fresh, filtered air 24 hours a day,” Conta says. “We get forest fires up here, so on a supersmoky day, the air inside this house is much cleaner than [in] the average house.”
The building shell is also superinsulated. If you were to look at a cross section of the house’s main walls, you would see the layers from the interior of the home to the exterior: Sheetrock, blown-in fiberglass insulation between 2-by-4-inch reclaimed studs, 4-by-8-foot sheets of plywood sheathing, a water-resistant barrier (WRB), 2 inches of mineral wool board, 1-by-4-inch rain screen strips, and then the exterior siding (either reclaimed wood or fiber cement, depending on which wall). “The mineral wool board is sort of like a wool sweater for the house,” Conta says.
Anna wanted to keep the kitchen simple, with white Shaker cabinets and locally sourced madrone wood countertops.
The couple had planned to connect the home to the deck with a big custom garage door, but they saved $5,000 by going with French doors instead. “It was much more cost-effective,” Anna says. “The French doors produce the same effect in summer when you open them up.”
Stools: Poly and Bark Paxton in tan, Edgemod Furniture
The couple had planned to connect the home to the deck with a big custom garage door, but they saved $5,000 by going with French doors instead. “It was much more cost-effective,” Anna says. “The French doors produce the same effect in summer when you open them up.”
Stools: Poly and Bark Paxton in tan, Edgemod Furniture
The window on the cabinet wall lets in the morning eastern sunlight that convinced Anna and Donovan, seen here, to flip the original layout.
Watch now: Go inside this 700-square-foot backyard cottage
Watch now: Go inside this 700-square-foot backyard cottage
The floating shelves are made of the same reclaimed lumber as what clads the exterior and the TV wall. Conta stained and sealed the wood here to hold up better to kitchen activity.
He added an outlet on the wall above the peninsula countertop so the Watts can plug in the speaker he gave the couple as a gift. “He thought so far ahead,” Anna says. “That really speaks volumes to working with a professional. They think ahead for you.”
Conta also placed outlets above the cabinets so the couple can plug in lights to uplight the wall.
He added an outlet on the wall above the peninsula countertop so the Watts can plug in the speaker he gave the couple as a gift. “He thought so far ahead,” Anna says. “That really speaks volumes to working with a professional. They think ahead for you.”
Conta also placed outlets above the cabinets so the couple can plug in lights to uplight the wall.
The couple chose cork flooring because it’s a sustainable, renewable material. It’s made from the bark of the cork oak tree. The bark regrows every nine years and can be harvested again without harm to the tree. The cork also holds warmth well and offers some spring underfoot, and its natural patterning hides dirt and pet hair. In addition to dog River, the couple has a longhair cat (part Maine coon, part Norwegian forest) named Lambert.
Anna wanted to keep the bathroom simple, as with the kitchen. A wood vanity complements wood tones found elsewhere in the house, and white tile keeps things classic. The floor tile has radiant heating below. “It’s amazing to go from the room-temperature cork to these warm heated tiles in the bathroom,” Anna says.
A large window near the ceiling brings in light while maintaining privacy. The window also frames views of evergreen trees that can be seen from the living room sofa when the bathroom door is open, even when the shower curtain is closed. “Beautiful sunlight filters through the trees and glows through that window into the living room,” Anna says.
A large window near the ceiling brings in light while maintaining privacy. The window also frames views of evergreen trees that can be seen from the living room sofa when the bathroom door is open, even when the shower curtain is closed. “Beautiful sunlight filters through the trees and glows through that window into the living room,” Anna says.
In the main bedroom, Conta added radiant-heat panels on the ceiling. “It kind of creates that campfire-cozy warmth,” he says.
Bed: modern wood queen spindle in Caramel, Walker Edison; nightstands: midcentury two-drawer solid wood in Caramel, Walker Edison
Bed: modern wood queen spindle in Caramel, Walker Edison; nightstands: midcentury two-drawer solid wood in Caramel, Walker Edison
Strategically placed windows frame leafy views while maintaining privacy in the bedroom, allowing the Watts to forgo curtains.
Dresser: three-drawer midcentury modern wood in Caramel, Walker Edison
Dresser: three-drawer midcentury modern wood in Caramel, Walker Edison
A 200-square-foot deck gives the Watts additional living, dining and entertaining space. “Outside time is so valuable to people that live in the Northwest,” Anna says. “I’m really excited to entertain and host friends out on this beautiful deck.”
Watch now: See more of how this backyard cottage was built using green building practices
Get the look: Shop for products from and inspired by this project
Table and benches: three-piece Rosario outdoor wood picnic dining set, GDFStudio; chairs: Aleah outdoor woven faux rattan, GDFStudio
More on Houzz
Watch more episodes of Houzz TV
Find home design professionals near you
Watch now: See more of how this backyard cottage was built using green building practices
Get the look: Shop for products from and inspired by this project
Table and benches: three-piece Rosario outdoor wood picnic dining set, GDFStudio; chairs: Aleah outdoor woven faux rattan, GDFStudio
More on Houzz
Watch more episodes of Houzz TV
Find home design professionals near you
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@bizeebees Thank you! We love our cork floors - best kept secret is that we don't clean as often as we used to on hardwood and vinyl floors because the cork texture hides pet fur and dirt really well! We just use the Swiffer wet jet wood floor cleaner and a vacuum and/or broom to keep clean!
I just have colored concrete for my floor, so it's easy to give it a quick cleaning with a Swiffer. Doesn't quite hide the dust as well as your cork floor! But it's easy to mop it once a month, and it's also my heating and cooling system, so I have multiple benefits from one investment.
I am interested to know the dimensions of the kitchen and living room, as I have a 710 square foot interior, and would like to have a larger kitchen.