Home Addition Architect

What can we do for you?

01. Pre-Design

Pre-design starts with listening to your story, your lifestyle, and what you want the addition to do. We then run a feasibility study that reviews local building and zoning codes, including height, floor area, setbacks, and critical areas, so you know what your property allows before design begins.

02. Design

In design, we turn your goals into floor plans that show the arrangement of rooms, dimensions, and how the new space connects to the old. We address natural light, sustainable features, and room layouts, and we use 3D modeling of interiors and exteriors so you can see the addition before it is built.

03. Permits

For permitting, we prepare the building permit drawings and handle the process of obtaining the permit. If the city issues review corrections, we respond to them and revise the plans as needed.

04. Construction

For construction, we provide construction drawings and details that translate the design into actionable plans for your builder or contractor. These include elevations, sections, and critical construction details, with instructions on materials, finishes, and construction techniques. We detail every element so the addition is structurally sound and compliant with local building codes.

Don't just take our word for it.

Here's what our clients have to say.

"RD's team provided us with a very special creative process designing our home...If you are seriously looking to elevate your next project, work with Refine Design!"

Shy F.

Mountain Lodge

"Stone and Julia were very professional and extremely helpful in designing our project. Their patience and attention to detail were integral in configuring a change of use building."

Dustin D.

Ballard DADU

"They not only helped bring our vision to life, but offered a point of view we had not thought of. I highly recommend this duo - they are incredibly easy to work with."

Kendall F.

Gig Harbor Remodel

"No words can describe how exceptional Julia and Stone are at their work...Not only did they research extensively into the building codes but they poured so much thought into the design."

Yu Chi S.

Seattle Bathroom Remodel

"It was great working with Refine Design Architecture for our cabin expansion. They listened to our requirements, offered feedback and produced designs that fulfilled our vision"

Antonio G.

Leavenworth Cabin Addition

"Their work was on schedule, on budget, and their ideas were very helpful. If you're searching for an architectural team that can fit the bill, look no further."

James M.

Accessibility Retrofit

Have questions?
We have answers.

Every home addition has its own site, structure, and zoning questions. Here are the ones we hear most often, answered plainly.

What is the home addition design process?

Our home addition process runs in four phases: pre-design and feasibility, design, permitting, and construction drawings. We guide you through each step and keep the dialogue open and transparent.

Pre-design: we listen to your goals and review local building and zoning codes, including height, floor area, setbacks, and critical areas.
Design: we develop floor plans and 3D models of the interior and exterior.
Permits: we prepare the building permit drawings, handle the permit process, and respond to review corrections.
Construction drawings: we give your builder the details needed to build the addition.

Do I need an architect for my home addition?

We recommend an architect for most home additions, because new space has to connect structurally to your existing house, meet zoning and building codes, and look like it belongs. Your local building department sets the specific requirements for your project. An architect takes on the technical work in several ways:

Reviewing height, floor area, setbacks, and critical areas before design starts.
Designing the addition to complement your home's existing design.
Preparing the permit drawings and responding to review corrections.
Detailing the construction drawings so the addition is structurally sound and code compliant.

How much does a home addition cost to build?

The construction cost of a home addition depends on its size, type, structural work, materials, and site, so we do not quote a single number without knowing your project. Larger additions and ones that change the existing structure involve more work than a simple extension. Self-contained spaces like mother-in-law suites and ADUs include a kitchenette, bathroom, and living space. Garage conversions must address insulation, heating, and ventilation. We review feasibility early and prepare detailed construction drawings that tell builders which materials, finishes, and techniques to use, so you can discuss scope and budget with contractors from clear information.

How long does a home addition take?

The timeline for a home addition depends on the size and complexity of the project, the condition of the existing structure, and how your local jurisdiction handles permit review, so we do not promise a standard duration. Design, permitting, and construction each take their own time. Structural changes, critical areas, and city review corrections can all extend the permitting phase. A feasibility study at the start helps surface zoning and code limits early, before they can slow the design.

What does a home addition architect cost?

A Home Addition Architect's fee depends on the scope of services and the complexity of your project, and we tailor our services project by project to fit your goals. Your project may call for some or all of the following services:

A feasibility study of local building and zoning codes.
Floor plan design and 3D modeling.
Building permit drawings and handling the permit process.
Construction drawings and details for your builder.
Interior design, including material, fixture, and finish selection.

Tell us what you are planning and we will explain what the services involve.

Why hire an architect for a home addition?

An architect designs your addition so it works structurally, meets code, and looks like part of the original house. We study your existing home and design each addition to complement it, whether it is a bedroom, a home office, or an ADU. We address natural light, sustainable features, and room layouts. We handle zoning and permit work, then detail the construction drawings your builder will use. Because we use a hands-on, transparent process, you stay informed at every step.