ADUs, DADUs, Outbuildings & Sheds

Accessory Structures

Making the most out of your property with supporting structures designed for life, work, and play.

Accessory dwelling units (ADUs), detached accessory dwelling units (DADUs), and outbuildings can help you make the most of your property.

As a standalone project or as a component of a larger investment in your home or yard, outbuildings and ADUs add specialized functionality in a small package. With in-house, multidisciplinary teams of architects, interior designers, and landscape architects, Board & Vellum has your project covered from all angles.

Whether you’re exploring options for a home office, art studio, guest cottage, custom bike shed, or just a space to relax, we love solving the unique challenges of designing custom DADUs and accessory structures, no matter what type of space you’re hoping to achieve.

Backyard Reading Retreat – Board & Vellum
Surrounded by Green

Even with the removal of the overgrown vegetation this space was designed to bring a clean and green feel to it, aided by the towering nearby trees and strategically placed lawn and planting beds within the backyard. Backyard Reading Retreat | Photo by Andrew Giammarco.

Surrounded by Green

Even with the removal of the overgrown vegetation this space was designed to bring a clean and green feel to it, aided by the towering nearby trees and strategically placed lawn and planting beds within the backyard. Backyard Reading Retreat | Photo by Andrew Giammarco.

Net Carbon DADU – Board & Vellum
Accessory Dwelling

A raised deck connects this new DADU to the main house on one level, and to the courtyard-inspired DADU patio below. Net Carbon DADU | Photo by Brian Hartman.

Accessory Dwelling

A raised deck connects this new DADU to the main house on one level, and to the courtyard-inspired DADU patio below. Net Carbon DADU | Photo by Brian Hartman.

Backyard Artist Studio – Board & Vellum
Focal Points

A round window creates visual interest by softening the lines of the structure and introducing new shapes to the site. Backyard Artist Studio | Photo by Meghan Montgomery

Focal Points

A round window creates visual interest by softening the lines of the structure and introducing new shapes to the site. Backyard Artist Studio | Photo by Meghan Montgomery

Capitol Hill Landscape – Capitol Hill Craftsman – Board & Vellum
Custom Bike Shed

The Ipe-clad bike shed keeps bikes secure and provides a visually pleasing place to keep trash, recycling, and compost bins out of sight. Capitol Hill Craftsman Landscape Design | Photo by Derek Reeves.

Custom Bike Shed

The Ipe-clad bike shed keeps bikes secure and provides a visually pleasing place to keep trash, recycling, and compost bins out of sight. Capitol Hill Craftsman Landscape Design | Photo by Derek Reeves.

Crow's Nest Cottage – Board & Vellum Interior Design FF&E
Adaptable Furniture

Though unassuming, the custom, handmade coffee table is designed to easily lower to the floor so it doesn't need to be moved when the Murphy bed is lowered.Crow’s Nest Cottage | Photo by Andrew Giammarco.

Adaptable Furniture

Though unassuming, the custom, handmade coffee table is designed to easily lower to the floor so it doesn't need to be moved when the Murphy bed is lowered.Crow’s Nest Cottage | Photo by Andrew Giammarco.

Adding density at the neighborhood scale.

When adding density to a neighborhood, DADUs offer an approach to multi-generational living, adding a rental unit, or increasing space to host guests that protects the neighborhood scale. Dubbed ”middle housing,“ this approach is at the forefront of efforts to create more livable cities.

With evolving code requirements, it’s important your design team recognizes the real-life feasibility of your desired accessory structure, understands the evolving legislative and code changes associated with it, and can take on the challenges of a complex permitting process. As a design firm with experience in both the single-family and multifamily sectors, our team has an unparalleled breadth and depth of knowledge about middle housing projects.

Plus, we’re always staying abreast of updates regarding legislation, so you can be confident your project is being considered with the most up-to-date information available.

A design sketch of a new detached garage with DADU and greenhouse entry, designed by Board & Vellum. – Accessory Structures Design, Architectural Design, DADU Design
Greenhouse Meet DADU

A unique greenhouse entry to a DADU above a detached garage adds not only another use, but stunning visual impact to this accessory structure. Rendering by Board & Vellum team.

Greenhouse Meet DADU

A unique greenhouse entry to a DADU above a detached garage adds not only another use, but stunning visual impact to this accessory structure. Rendering by Board & Vellum team.

Problem-solving across disciplines.

Integrated design teams create holistic projects.

Though smaller than a new home, pursuing an accessory structure can be deceptively complicated. But they’re often equally personal — they require a careful combination of architecture, site design, and interior design considerations to ensure they are code compliant, suited to your property, and perfect for your desired use.

That makes your ADU, DADU, or other accessory building project a great fit for the multidisciplinary team at Board & Vellum. Our integrated teams of architects, interior designers, and landscape architects are dedicated to your project from the outset, considering it holistically through deeply-rooted collaboration across disciplines.

Residential Landscapes

The experience of your home doesn’t end at the walls of your house. Our site design team cohesively blends indoor and outdoor living with beautiful, functional spaces lush with life.

Residential Interiors

From a light touch to comprehensive services, our interiors team loves to collaborate with you to add the details that create beautiful, meaningful spaces you’ll love to call your own.

Ready to create something new?

Move forward with a team that can guide your project to success.

ADUs, DADUs, and outbuildings are incredibly special projects. A microcosm of custom residential design, accessory structures are complex projects with immense scope for imagination.

Each of the accessory structures in our portfolio is as unique as the client we designed them for. We’ve successfully designed — and shepherded through construction — accessory structures with a variety of program goals while navigating additional complexities, such as environmentally critical areas, sustainability certifications, and highly-individualized spaces that not only feel cohesive with the main home, but blend in seamlessly with the property as a whole.

We revel in creating these highly personal spaces that tell the distinct stories of the individuals who use them. Whether you’re creating additional living space, a home office, a studio, or another dream space, Board & Vellum has the experience and knowledge to tackle your distinct accessory structure, inside and out.

Right from the start, our approach brings together key players, so design, budget, permitting, and construction yield as few surprises as possible. The result is a beautiful and tailor-made space, customized for whatever special use you have in mind.

Highlights from our portfolio of accessory structures.

Even small spaces can make big statements. We love creating custom spaces, no matter the size.

Backyard Reading Retreat – Board & Vellum
Transforming an Overgrown Backyard

Backyard Reading Retreat

This backyard and petite shed form an urban oasis: the perfect place to relax and recharge in the busy city with a great book.

A Sustainability-Minded DADU with a View

Net Carbon DADU

Guided by sustainable principles from the foundation to the finishes, this DADU is estimated to be carbon negative.

Two bar stools at the counter in this Petite Condo Kitchen, by Board & Vellum.
A Small, Highly-Functional Kitchen

Petite ADU Kitchen

With an integrated kitchen cabinet system from Henrybuilt, this kitchen has clean lines and is highly functional.

Crow's Nest Cottage – City Cottage – Board &  Vellum Interior Design FF&E
Crow’s Nest Cottage

Crow’s Nest Cottage | Photo by Andrew Giammarco.

Furniture, Fixtures, Art & Accessories

Crow’s Nest Cottage

A tiny, adaptable guest house with a modern, moody, Pacific Northwest vibe: a cottage is full of “creature comforts.”

Backyard Artist Studio – Board & Vellum
16x9-backyard_artist_studio-exterior-view_1-day

Backyard Artist Studio | Photo by Meghan Montgomery

Relaxing Creative Spaces in a Backyard Oasis

Backyard Artist Studio

The addition of a new yoga and artist studio shines in a flourishing backyard with organic siting, playful materials, and creative details.

Capitol Hill Landscape – Capitol Hill Craftsman – Board & Vellum
Site Design & Landscape Architecture

Capitol Hill Craftsman Landscape Design

Crisp, new walkways and plantings, along with a great-looking bike shed, help this home feel anchored in its yard.

Highlights and helpful posts from our blog.

Our blog isn’t written for other architects and designers. It’s designed to be a helpful, approachable resource for you.

Aerial view of a single-family residential neighborhood for a blog post on middle housing.

The Middle Housing Bill FAQ

HB1110 is Washington State’s answer to addressing the housing crisis and the “missing middle.” Here’s what we currently know about the impacts of this legislation.

Board & Vellum's portfolio includes architecture, interior design, and landscape architecture projects, like this backyard cottage.

Why We Need Middle Housing

Here’s our take on why middle housing is an important part of increasing affordability and equity, based on our understanding of Washington State’s Middle Housing Bill.

Backyard Artist Studio – Board & Vellum
Layering of Space

The backyard oasis is comprised of layered spaces and programs — framed by the new garage and studio, and the main house. Backyard Artist Studio | Photo by Meghan Montgomery

Using Drones for Site Planning

We’re breaking down all the ways drone technology can improve your project, create efficiencies, and help you collaborate with your design team.

Considering a project, or curious about something?

Say hello, and send us your questions via the form below. We’re always pleased to make new connections, and eager to get to know you, your project, and your goals.

Get in touch.