Home additions
More home, designed around how you actually live
Whether you're adding a sunroom, a master suite, or an entirely new floor, Bay State Design & Construction builds additions that feel like they were always part of the plan. Custom design, in-house blueprints, permits, and construction — start to finish.
Team Experience
Projects
rating Average
Our Approach
Home additions that feel like they were always there
Most people come to us at a turning point. The family is growing. A parent is moving in. You've outgrown the house but you love the neighborhood. Whatever the reason, an addition is one of the bigger decisions you'll make as a homeowner — and one of the easier ones to get wrong if the design and construction aren't in sync from day one. At BSDC, they are. We design your addition in-house, draw the structural documents, pull the permits, and build it ourselves. What that means for you is a space that looks and feels like it was always part of your home — not something that got bolted on.
Sometimes an addition is the starting point for something more — an ADU, in-law suite, or self-contained living space on your property. If your project is headed that direction, our FlexUnit™ service might be the smarter path.
Reasons to Add on
When does a home addition make sense?
- Your family has grown and the house hasn't kept up
- You want a parent or family member close without sacrificing privacy
- You've priced moving and adding on pencils out better
- You need a dedicated space that doesn't exist yet — a home office, a guest suite, a garage
- You want to convert unused outdoor space into something year-round
- You love where you live and want to invest in it long-term
What we can build
How home additions comes to life
Here's what is possible with a home addition. Have ideas of your own already? We'd love to hear them during your free consult.
Our Portfolio
Snapshots of recent projects
REviews
Hear from happy homeowners
Great guys and easy to work with! I couldn't be happier with my beautiful new kitchen!
The best! Gave a super reasonable estimate and walked me through all the steps and timeline , finally have my (dream) kitchen.
I highly recommend Bay State Design & Construction to anyone looking for reliable, skilled, and professional construction services.
These guys are amazing! Helped me build a two story addition with a master suite and I couldn't be more thrilled with the product.
The guys from Bay State design were prompt well priced and kept my project moving without missing a step. Great work guys!
I hired these guys to build an attached garage at my house. Throughout the entire process they went above and beyond all expectations and their pricing was super fair.
This team is very professional, communicative and great to work with. Gio provided comprehensive building plans for me within a short timeframe, as promised.
How it Works
Typical kitchen remodel process
Site Visit & Consultation
Lorem ipsum dolor sit amet, consectetur adipiscing elit. Suspendisse varius enim in eros elementum tristique. Duis cursus, mi quis viverra ornare, eros dolor interdum nulla, ut commodo diam libero vitae erat. Aenean faucibus nibh et justo cursus id rutrum lorem imperdiet. Nunc ut sem vitae risus tristique posuere.
We visit your home, meet with you, and walk through your vision, goals, and any structural considerations.
Detailed estimate
Lorem ipsum dolor sit amet, consectetur adipiscing elit. Suspendisse varius enim in eros elementum tristique. Duis cursus, mi quis viverra ornare, eros dolor interdum nulla, ut commodo diam libero vitae erat. Aenean faucibus nibh et justo cursus id rutrum lorem imperdiet. Nunc ut sem vitae risus tristique posuere.
We develop a thorough estimate based on your agreed scope of work — no surprises, no vague line items.
Contract & Design Session
Lorem ipsum dolor sit amet, consectetur adipiscing elit. Suspendisse varius enim in eros elementum tristique. Duis cursus, mi quis viverra ornare, eros dolor interdum nulla, ut commodo diam libero vitae erat. Aenean faucibus nibh et justo cursus id rutrum lorem imperdiet. Nunc ut sem vitae risus tristique posuere.
Once you accept the estimate, we send over a contract and schedule a design session to lock in materials, finishes, and layout.
3D Render & Construction docs
Lorem ipsum dolor sit amet, consectetur adipiscing elit. Suspendisse varius enim in eros elementum tristique. Duis cursus, mi quis viverra ornare, eros dolor interdum nulla, ut commodo diam libero vitae erat. Aenean faucibus nibh et justo cursus id rutrum lorem imperdiet. Nunc ut sem vitae risus tristique posuere.
We produce a 3D rendering of your space and all structural construction documents entirely in-house.
Permits & materials
Lorem ipsum dolor sit amet, consectetur adipiscing elit. Suspendisse varius enim in eros elementum tristique. Duis cursus, mi quis viverra ornare, eros dolor interdum nulla, ut commodo diam libero vitae erat. Aenean faucibus nibh et justo cursus id rutrum lorem imperdiet. Nunc ut sem vitae risus tristique posuere.
We apply for all required permits and order long-lead materials as soon as they're issued — keeping your project on schedule.
Construction & inspections
Lorem ipsum dolor sit amet, consectetur adipiscing elit. Suspendisse varius enim in eros elementum tristique. Duis cursus, mi quis viverra ornare, eros dolor interdum nulla, ut commodo diam libero vitae erat. Aenean faucibus nibh et justo cursus id rutrum lorem imperdiet. Nunc ut sem vitae risus tristique posuere.
Work begins. We manage every phase of construction and every required inspection through final sign-off so nothing gets missed!
Bay State Design & Construction
Why homeowners choose BSDC
One point of contact, start to finish
No chasing down architects, contractors, or permit offices. You have one team and one person to call, from first sketch to final walkthrough.
We design around your budget
Many firms design the dream, then hand you a bill that doesn't match it. We start with your number and build the plan around it — no sticker shock.
Your vision survives the build
A lot gets lost when the design firm hands off to the contractor. We can draw the plans and build to them. AKA: what you approved is what gets built.
Your timeline is ours to protect
When design and construction live under one roof, no one else's schedule can slow yours down. We control the process so you're not waiting on a separate third party to move forward.
Frequently Asked Questions
Home addition FAQs
Yes, always. Additions involve structural work, and permits exist to make sure it's done safely and to code. We handle the entire permitting process in-house — filing, follow-up, and managing every inspection from start to finish.
It depends heavily on scope. A mudroom or breezeway may wrap up in a few weeks. A multi-story addition or basement build runs longer — often several months. We'll give you an honest timeline during the estimate, not a number designed to get you to sign.
That's the goal every time. We look at your roofline, siding, trim, and interior finishes and design the addition to feel continuous with the rest of the house. A good addition shouldn't look like an addition.
A three season porch is designed for spring through fall — screened or windowed but not insulated or climate controlled. A four season porch is fully insulated with heating and cooling, so you can use it year-round. We build both and can help you decide which makes sense for how you want to use the space.
Yes. Most of our additions include at least one of these. Plumbing, electrical, and mechanical work are all handled in-house, so there's no coordinating with outside trades.
An ADU is an accessory dwelling unit — a self-contained living space on your property, sometimes called an in-law suite or guest house. We build them as part of our FlexUnit™ service. If that's where your project is headed, that page is worth a look.
Every project comes with a 1-year workmanship warranty. If something isn't right with our work, we come back and make it right.
Thinking about adding on?
More space, thoughtfully designed and properly built. Let's see your property and figure out what makes sense.