Additions & ADUs - Marnella Homes

Additions & ADUs in Camas, WA for Flexible, Future-Ready Living

Your life has changed, but your home has not kept up. You may need a quiet office, space for aging parents, a private suite for guests, or a small rental to offset your mortgage.

Our additions and ADU service in Camas, WA, helps you add space that feels natural, works well for everyone who lives there, and performs as efficiently and comfortably as the rest of your home.

Is This the Right Fit for You?

This service is a good match if:

You want more space but prefer to stay in your current neighborhood
You are considering a primary suite addition, family room, office, or multi-generational suite
You are exploring an ADU (Accessory Dwelling Unit) for family, guests, or rental income
You care about privacy, sound control, and reasonable layout, not just extra square footage
You want the new space to match or exceed the comfort and efficiency of the rest of your home
You would rather do one well-planned project than a series of small, disconnected additions

If you are looking for thoughtful added space that feels like it has always belonged, this service is built for you.

Additions, ADUs & Multi-Generational Spaces With Marnella

When we design and build an addition or ADU, we are careful not to “bolt on” a room. We look at your existing home, your site, and how the new space will be used, then shape a solution that integrates structure, style, comfort, and performance. That may mean a seamless primary suite on the main level, a light-filled family room that connects more closely to your yard, or a fully self-contained ADU with its own entry, kitchen, and bath. In every case, we pay attention to privacy, sound, and circulation, and we update the envelope and mechanical systems. Hence, the new area is as comfortable and efficient as the rest of the home. The result is extra space that feels intentional, not like an afterthought.

How the Process Works for Additions & ADUs

1. Site & Home Review

We start with a visit to understand your existing home, lot, and utilities. We talk about who will use the new space, how it should feel separate, and your long-term plans (family, work, rental, resale).

2. Concept Design & Feasibility

Next, we explore concepts: where the addition or ADU should go, how it connects (or intentionally separates) from the main house, and what is realistic within zoning, setbacks, and budget. We also look at structure, access, daylight, and parking where required.

3. Performance & Systems Planning

We then plan how the new space will be heated, cooled, and ventilated, and how it will tie into (or operate separately from) your existing systems. This step helps ensure comfort, efficiency, and good indoor air quality.

4. Detailed Scope, Pricing & Approvals

Once the concept and systems approach are straightforward, we finalize the scope, selections, and pricing. We prepare the drawings and documentation required for permits and approvals, and keep you informed of timelines and next steps.

5. Construction & Coordination

During construction, we work to limit disruption as much as the work allows, coordinate trades, and protect areas of the home that are not being touched. We schedule walkthroughs at key points so you can see progress and ask questions.

6. Completion, Orientation & Support

At the end, we walk you through the finished space, explain how everything works, and address any final details. Our warranty and aftercare support continue after move-in, whether the space is for family, guests, or tenants.

Recent Projects: Smart, Integrated Extra Space

What Homeowners Say

Built on Trust. Inspired by You.

Our homeowners are at the heart of everything we do. From thoughtful design to lasting quality, their stories reflect our commitment to creating homes that nurture well-being, comfort, and pride. Hear what makes the Marnella Homes experience truly exceptional.

      EXCELLENT  
   Based on 8 reviews 
    
 
 
 
   
 
 
       Posted on Google  
   
   Shan Stassens 
 
 
 
 Trustindex verifies that the original source of the review is Google. Marnella Homes holds every project to exceptionally high standards. From thoughtful design and detailed energy modeling to professional construction and execution, their team consistently delivers outstanding results.
  
 
      Posted on Google  
   
   Patrick Spriggel 
 
 
 
 Trustindex verifies that the original source of the review is Google. Most people scroll to the bad reviews, but you must read this good one.  And, we are not affiliated with any of the Marnella team other than being a customer. I have been around home building and contractors for decades and know just enough to able to determine what is quality, good quality or great quality.  We purchased a new townhome on E. 6th St. in Vancouver from Tony Marnella.  The technology that comes as the standard offering is absolutely amazing.  Everything has been thought through as if the builder were making for themself.  The quality of the build is crazy high thanks to the Marnella team.  Tony Marnella may be the owner but he is extremely hands-on.  His foreman is picky as if it were his own.  And, Gina, in his office is absolutely amazing.  The team works in concert and they don't miss a single detail. We love our home and the location is a bonus! Look no further if you need a builder.
  
 
      Posted on Google  
   
   Doug Bixel 
 
 
 
 Trustindex verifies that the original source of the review is Google. We were introduced to Marnella Homes through a friend.  Marnella took our custom build project on, improved the design, and completed the project within the allotted schedule.  In today's marketplace, there are very few companies that can do that.  We are very happy with the home!  Thank you Team Marnella!
  
 
      Posted on Google  
   
   Andy Steigleder 
 
 
 
 Trustindex verifies that the original source of the review is Google. Marnella Homes exceeded all our expectations on our custom home. From start to finish, their devotion to the client was clear in every interaction. They truly listened to our needs and made sure we felt involved and informed throughout the entire process. Their attention to detail in their work is exceptional—every finish, fixture, and feature was thoughtfully executed with care and precision. They delivered everything right on time, staying true to their schedule without cutting corners and even redoing work if not meeting their high standards. I would gladly use Marnella again on a new project.
  
 
      Posted on Google  
   
   Qwan Pham 
 
 
 
 Trustindex verifies that the original source of the review is Google. Building with Tony and the Marnella Homes team was a smooth and surprisingly stress-free experience. This was our fourth new home, and we didn’t think it could be this easy. Despite building on the Oregon coast, where it’s often hard to find reliable tradespeople, the entire process—from breaking ground to getting the keys—took just six months. The home is high-quality, energy-efficient, and exactly what we hoped for. We appreciated the clear weekly updates, the detailed schedule, and the billing that matched the cost estimates. After moving in, Gina and Adrian were responsive and quick to take care of any follow-up issues. We’d happily recommend Marnella Homes and would work with them again in the future.
  
 
      Posted on Google  
   
   Laura 
 
 
 
 Trustindex verifies that the original source of the review is Google. Tony and his team built us a beautiful home in about one year.  The estimate was quite a bit shorter, but I think this is just the way things go. Using his home plan, we were able to tailor the space to our design aesthetic and partner along the way to get things right. Our PM, Damon was indispensible, a good listener and responsive.

FAQs

How much does an addition or ADU usually cost?

Costs vary based on size, complexity, and whether it is attached or detached. We will discuss your budget early and then build a detailed scope and price so you know where you stand before committing.

How long does this type of project take?

Design, approvals, and permitting can take several weeks to a few months. Construction often takes a few months or more, depending on the scale. We will provide you with a project-specific timeline before work begins.

How disruptive will the work be to our daily lives?

There will be noise, dust, and some loss of access to parts of your home or yard while we build. We plan with you, protect unaffected areas, and keep you updated so you can work around key phases.

What do you handle and what don’t you do?

We manage design collaboration, structural and mechanical planning, permits, and complete construction of the addition or ADU. We generally do not take on tiny, stand-alone “shed” projects or cosmetic-only work that ignores structure and systems.

Ready to Explore an Addition or ADU in Camas, WA?

If you need more space and want it to feel intentional, comfortable, and future-ready, we would be glad to help you think it through. We will review your home and lot, talk through how you want to use the new space, and map out what it would take to create an addition or ADU that genuinely works for your life in Camas, WA.

Schedule an Addition & ADU Planning Conversation