ADU and DADU design

Runtime:

discussed individually*
Project’s cost:

discussed individually**
Architectural supervision:

discussed individually

* Depends on the Project

** Price depennds on the style and complexity of the Project.

An accessory dwelling unit is a small home on your lot: a backyard cottage (DADU) or a unit attached to the house, built into a basement, an attic or over a garage (AADU). It can house parents, grown children or guests, work as a studio or bring rental income. We design ADUs in Seattle, Bellevue and Kirkland, from the first check of what your lot allows to drawings prepared to local code and signed by licensed professionals we work with.

Small houses are something we know well. The Minimalism House in the Carpathians fits a one-bedroom home into 75 m² (about 800 sq ft), with a living area, a kitchen, panoramic windows, wood and metal, and the cottage settlement in the same mountains includes compact one-bedroom houses planned to keep construction and maintenance costs low.

Our portfolio

Embracing Silence: The Enchanting One-Bedroom "Minimalism House" in the Carpathians

Cottage settlement in the Carpathian Mountains, Ukraine 2023

Examples of our work

ADU and DADU design: Embracing Silence: The Enchanting One-Bedroom

ADU and DADU design: Cottage settlement in the Carpathian Mountains, Ukraine 2023

Stages

01

04

Lot check

Zoning, setbacks, height, coverage, trees, utilities and access.

02

04

Position and layout

Options for where the unit stands and how its rooms work.

03

04

Concept and interior

Facades, materials and the interior shown in renderings.

04

Drawings

The permit set and construction drawings to local code, signed by licensed professionals we work with.

Q&A

What is the difference between an ADU and a DADU?

A DADU is detached, a separate small house in the yard. An attached ADU is part of the main house: a basement, an attic, an addition or a space over a garage.

Can I build an ADU on my lot?

Most residential lots in Seattle can have one or more ADUs. Size, height and position depend on the lot, so we check the current code for your address first.

How big can it be?

It depends on the city and the lot. We show what your lot allows and design the most useful plan within it.

Do you prepare permit drawings?

Yes. Our architects prepare the drawings to local code, and licensed professionals we work with sign them.

Can an ADU be rented out?

In Seattle and under Washington law an ADU can be rented. Short-term rental has its own rules and license.

Do you design the interior too?

Yes, the interior, built-in furniture and materials, so a small home is finished as one project.

Do you have any more questions?

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Home Additions

House Plans

Passive House and Sustainable Design

Landscape design

Contact us

dezzign.architects@gmail.com
+14254719496
Seattle, USA & Kyiv, Ukraine
Mon - Sat: 9.00 - 20.00

Backyard cottage (DADU) - a separate small house in the yard, with its own entrance and outdoor space.
Attached ADU - a unit in the basement or attic, or an addition to the house.
ADU over a garage - a home above a new or existing garage.
Garden studio - a small building for work, art or guests.
Home for parents - a single-level unit with a step-free entrance and a bathroom that works for later years.

What Your Lot Allows

Before drawing anything we check zoning, lot size, setbacks, height, lot coverage, protected trees, utilities and access for construction. Seattle's ADU rules have changed several times since 2019 and again with Washington's 2023 housing laws, so we work from the current code for your address, not from old guides. Bellevue and Kirkland have rules of their own.

A Small Plan That Lives Large

In a few hundred square feet every inch is used: an open living area and kitchen, a bedroom that fits a real bed and a closet, a bathroom with a walk-in shower, a place for a washer and dryer and built-in furniture. High windows and skylights bring in light without looking into the neighbor's yard, and a vaulted ceiling makes the main room feel larger.

Built for the Climate

We detail ADUs for the Pacific Northwest: a rainscreen behind the cladding, the continuous insulation and efficient windows required by the Washington State Energy Code, a heat pump and good ventilation, so a small house stays dry and inexpensive to run. See passive house and sustainable design.

Privacy for Both Households

The ADU and the main house each need their own entrance, path and outdoor space, windows that do not look into each other and, for attached units, sound insulation between floors and walls. We place the unit on the lot with this in mind and plan the garden around it with landscape design.

How We Work

We start with the lot, the budget and who will live in the ADU, then prepare options for its position and layout, a concept with renderings, the permit set and the interior. Our architects prepare the drawings to local code, and licensed professionals we work with sign them. See also home additions and custom home design.