More On Home Additions
What We Build
Designed for DC Homes
DC was built with foundations that made sense in 1920. Six feet of clearance. Moisture that comes and goes. A space that has technically existed the whole time you have owned your home and done nothing for you.
A basement dig out changes that. The floor gets excavated to create real ceiling height. The foundation walls get underpinned. The waterproofing gets done properly so dry means dry.
What clients do with it varies. A basement ADU that offsets the mortgage. A guest suite with actual privacy. A home office that is not also the dining room. In a city where adding above ground means navigating height limits and lot coverage rules, going down is often the most straightforward path to real square footage. Many older DC basements also have moisture and drainage problems quietly causing damage. A properly executed dig out fixes them at the source.
How It Works
Design & Engineering Working Together
Most renovation projects are design problems. A basement dig out is an engineering problem that ends with a design problem.
Before anything gets drawn, you need to know what the soil under your home is doing, what the foundation walls can handle, and how water moves through the site. In a DC rowhouse, you also have neighbors on one or both sides. Excavating next to a shared wall is not something you improvise.
Basement dig outs go wrong when engineering, design, and permitting are not talking to each other. The waterproofing spec gets missed. The ceiling height is two inches short because of a mechanical run nobody flagged. The permit stalls because egress was not checked before drawings were finalized. Blue Star handles all of it under one roof. Structural decisions shape the design from the start. Permitting runs in parallel. The finished space reflects what was actually planned, not what survived the handoffs.
We think through all of it first:
- Soil conditions and structural assessment before design starts
- Foundation underpinning that accounts for neighboring properties
- Waterproofing and drainage that keeps the space genuinely dry
- Egress windows for natural light and DC code compliance
- Ceiling height planning around existing mechanical systems
- Neighbor coordination in rowhouse blocks
The difference between a dig out done well and one done poorly does not show up in the listing photos. It shows up three winters later.
Why Blue Star
The Right Team Makes All the Difference
A basement dig out is one of the most technically demanding projects a DC homeowner can take on. Soil conditions, foundation integrity, moisture management, and rowhouse party walls all have to be understood before design begins. It takes a team that knows the engineering as well as the architecture.
Blue Star is an Architect-Led Design Build firm, and on a basement dig out that distinction is everything. When the architect and builder are the same team, structural decisions shape the design from the start and nothing gets missed between the drawing table and the job site. Our process is built around three things: Lifestyle Driven Design, Craftsmanship with Architectural Details, and a Transparent Process.
Lifestyle Driven Design
What you do with the space once it is dug out is entirely up to how you live. A rental unit, a guest suite, a home office, a family room. We start by understanding what your household actually needs before anything gets drawn, then design around that.
Craftsmanship & Quality Details
A basement done well looks like it was always part of the house. We are deliberate about waterproofing, ceiling height, mechanical coordination, and every finish decision that determines whether the space performs the way it should for years to come.
A Transparent Process
Basement dig outs require structural permits, staged inspections, and in some cases historic review and party wall coordination. We manage all of it and keep you informed at every step. You will know what your project requires, what the timeline looks like, and what drives the budget before any work begins.
What Has Been Sitting Under Your Home This Whole Time?
If you have a crawl space, a low-ceiling storage area, or a basement collecting moisture, it is worth a conversation about what is possible.
We ask questions, look at what you have, and tell you honestly what the project would involve and cost. Some homes are strong candidates. Others need a different approach. You will leave knowing which one yours is.
If this has been in the back of your mind for a while, that is exactly the right time to call.
Recognized by the Industry, Trusted by Our Clients
Thank you to our wonderful clients, exceptional employees, trusted partners and all those who help us produce wonderful work! We’re proud to be a multiple PRO MidAtlantic awards winner again in 2026 – 8 years in a row.
- Dream
- Design
- Build
- Enjoy
Most DC homeowners have a basement they have been meaning to do something with. Too low to finish. Too damp to use. Full of things that could live anywhere else.
Blue Star designs and builds basement dig outs that turn that space into something people actually want to be in. Real ceiling height. Real waterproofing. Real rooms. Same address, more home.
We are based in Washington DC and have spent more time than we care to admit thinking about what is under DC rowhouses. The soil conditions, the foundation situations, the moisture patterns. It is a specific city with specific problems and we know how to solve them.
Happy Clients
Blue Star’s best trait is their attitude. Everyone is unfailing polite, even when things got hard. And when things went wrong, which I fully anticipated would happen, you guys did the right thing every single time.
When you buy from Eric and his team, you can rest assured that they will address problems your inspectors couldn’t see.
The craftsmen used were excellent. We were impressed with their work and attitude and ability to creatively work around issues. The addition seamlessly integrates into the rest of the house and it’s hard to believe that the new spaces haven’t always existed as part of the original home.
Blue Star loved the architectural and design challenges I handed them, and each time I came up with a new idea, they were driven to figure out the best way to deliver.
I was very pleased with my experience with Blue Star. The reason for the top 5-star rating is three fold- the quality of the work, the prices they obtained for materials and the design elements. I did a large renovation (kitchen, 3 bathrooms, HVAC, plus knocked down some walls) which took about 4 months.
Blue Star came in on budget and ahead of a very, very tight and critical schedule. We highly recommend them to anyone considering a renovation.