in Chicago
every addition
& insured
Home additions Chicago: add the space your home is missing
Bofran Builders is the design-build team for home additions Chicago and suburban homeowners call when they need more space — room additions, second stories, bump-outs, sunrooms and ADUs that connect seamlessly to the home you already love. Family-owned, licensed and insured since 1999.
A home addition built to feel like it was always there
Adding more room is about more than square footage — it's about making your home work for your family. We build additions that connect to what's already there, so the new space never feels like an afterthought.
As a licensed Chicago general contractor, we manage every detail of your addition: design, permits, foundation, framing, roofing, drywall, electrical, HVAC and finishes. From second stories and bump-outs to finished basements and ADUs, you get one accountable team from first sketch to final walkthrough — and a home that feels bigger but still feels like home. Planning outdoor living as well? We build decks and porches that tie into the new space. Need the numbers first? Try our home addition cost calculator or read the full Chicago home addition cost guide.
- Design-build under one roof — no juggling separate architects and crews
- We pull and manage every Chicago building permit and inspection
- In-house framing crew, so the bones of your addition are done right
- Transparent, itemized pricing — no surprise change orders
- Built for Chicago weather with materials that hold up season after season
- Backed by a 5-year warranty and a 30-day post-project check-in
Every kind of home addition
Not sure which type fits your house and budget? Tap through the options below to compare typical cost, timeline and what each addition is best for — then run your own numbers in the calculator.
Room Additions
The most flexible way to grow your home — an extra bedroom, a home office, a bigger bathroom or a family room. We tie the new foundation, framing and roofline into the existing structure so it reads as one continuous home, inside and out.
- Extra bedroom, office, playroom or bath
- Full foundation, framing, roofing & finishes
- Great for growing families who want to stay put
Second-Story Additions
Perfect for Chicago ranch homes and bungalows on tight lots. We add a full second floor — bedrooms, baths, even a primary suite — when there's nowhere left to build out. This is structural work, and our in-house framing crew is built for it.
- Add 2–4 bedrooms and a full bath upstairs
- Keeps your yard and lot footprint intact
- Reinforced foundation & load paths engineered to code
Bump-Out Additions
A bump-out borrows just a few feet to transform a cramped kitchen, bathroom or eating nook. It's the most budget-friendly way to gain functional space without the cost of a full room addition or new foundation run.
- Expand a kitchen, bath or breakfast nook
- Often the lowest cost-per-project addition
- Minimal disruption to the rest of the house
Kitchen Extensions
Open up the kitchen, add an island, and connect it to a bright dining or living area. Kitchen extensions carry a higher per-square-foot cost because of cabinetry, plumbing and appliances — but they're consistently among the highest-return additions at resale. If your project is more remodel than addition, see kitchen remodeling in Chicago.
- Open-concept kitchen, island & dining space
- Full plumbing, electrical & appliance integration
- Among the strongest returns on investment
Primary Suite Additions
Add a true owner's suite — spacious bedroom, walk-in closet and spa-style bath. A primary suite addition is one of the most desirable upgrades for Chicago homes that were built without one, and it adds real square footage where buyers value it most.
- Bedroom, walk-in closet & en-suite bath
- Can sit on the main level or top a second story
- High buyer demand in city and suburban markets
Sunrooms & Four-Season Rooms
Bring the outdoors in with a glass-wrapped room you can use 365 days a year. A 4-season room is fully insulated and climate-controlled; a 3-season room is a lighter, lower-cost option for spring through fall. Both add bright, flexible living space.
- 3-season ($100–$200/sq ft) or insulated 4-season build
- Floods adjacent rooms with natural light
- Doubles as a dining, lounge or plant room
Garage Additions & Conversions
Build a new garage, add living space above it with a rooftop deck, or convert an existing garage into a heated room, studio or in-law space. Conversions are among the most affordable ways to add finished square footage because the shell already exists.
- New garage, garage-top suite, or full conversion
- Lowest cost-per-sq-ft of any addition type
- Great for a studio, gym, office or in-law space
Attic Conversions
Turn an unused attic into a bedroom, office or flex room. We add insulation, proper egress, stairs, electrical and finishes to bring it fully up to code — gaining a whole floor of usable space without changing your home's footprint.
- New bedroom, office or bonus room
- Code-compliant egress, insulation & stairs
- No change to your lot or exterior footprint
ADUs & In-Law Suites
An Accessory Dwelling Unit gives you a self-contained living space — for aging parents, adult kids or rental income. With Chicago's expanding ADU rules, this is one of the most future-proof additions you can make. We handle the zoning, permits and full build.
- Independent kitchen, bath & living area
- Multigenerational living or rental income
- We navigate Chicago's ADU ordinance & permits
Home addition cost calculator
Get an instant, Chicago-specific ballpark for your project. Choose your addition type, set the square footage, and pick a finish level — your estimated cost range and potential added home value update in real time. You can also open the full home addition cost calculator with every option explained.
Estimates are planning ranges based on 2025–2026 Chicago-area pricing and your inputs — actual cost depends on design, site conditions, materials, permits ($500–$5,000) and finish selections. New foundation work typically adds $20–$40/sq ft. For a firm, itemized number, request a free on-site estimate.
What home additions actually cost in Chicago
Most Chicago home additions run $150 to $320 per square foot, but the type of addition and your finishes move that number a lot. Here's how it breaks down — and how a few common project sizes tend to land.
Cost per square foot by type
| Addition type | Cost / sq ft |
|---|---|
| Garage conversion | $50–$150 |
| Basement finishing | $70–$155 |
| Sunroom (3-season) | $100–$200 |
| Attic conversion | $100–$200 |
| Bump-out / room addition | $150–$300 |
| Sunroom (4-season) | $200–$400 |
| Second-story addition | $200–$400+ |
| ADU / in-law suite | $200–$400 |
| Kitchen extension | $250–$500 |
By project size
| Size | Typical total |
|---|---|
| 240 sq ft garage conv. | ~$70,000 |
| 100 sq ft kitchen ext. | ~$75,000 |
| 400 sq ft room add. | $60K–$120K |
| 500 sq ft addition | $75K–$150K |
By location
| Area | Cost / sq ft |
|---|---|
| Chicago | $160–$320 |
| Glenview | $158–$315 |
| Evanston | $155–$310 |
| Oak Park | $152–$305 |
| Naperville | $150–$300 |
Cost drivers to keep in mind: foundation work (+$20–$40/sq ft), Chicago permits ($500–$5,000), union vs. non-union labor (10–30% difference), and per-system utility integration ($5K–$15K) for kitchens, baths and ADUs. See the full Chicago home addition cost breakdown.
An addition is an investment, not just an expense
A well-built addition is one of the most reliable ways to raise your home's value — and unlike a move, it lets you keep your neighborhood, your school district and your commute. In high-demand Chicago neighborhoods, the right addition often recoups most of its cost while giving your family years of everyday use.
The biggest returns tend to come from additions that fix what buyers notice most: a missing bedroom, a cramped kitchen, or the lack of a primary suite. Square footage in the right place is what moves an appraisal.
Three clear steps from idea to move-in
No mystery, no runaround. You always know what's done and what's next. Most additions take 3–6 months start to finish, depending on size and type.
Plan the project
We start with a free consultation and on-site assessment, talk through how you want to use the space, and develop a design and a clear, itemized estimate. No obligation, no pressure.
Permits & final details
We handle all Chicago permit applications, drawings and approvals, finalize your material selections, and lock in the build schedule — so everything is buttoned up before a single wall goes up.
Build & your new space
Our crew builds — foundation, framing, roofing, systems and finishes — keeping you updated the whole way. We finish with a final walkthrough, then a 30-day check-in and your 5-year warranty.
A Chicago addition contractor that keeps it simple
We're a family-owned business that's been building and renovating in Chicago since 1999. Here's what you get when the owner is on your job.
Licensed & insured
A licensed and insured Chicago general contractor, so your addition meets local code and your investment is protected from day one.
Clear communication
Direct owner involvement and frequent updates. You'll always know what's happening on your project and what comes next — no chasing.
Competitive pricing
Strong local supplier relationships let us source high-quality materials without the premium price — and pass the savings to you.
In-house framing crew
The bones of your addition are built by our own framers — straight walls, solid floors and a structure that stays true for decades.
Permits handled
We manage every permit, drawing and inspection so your addition is fully Chicago-code-compliant — and you never set foot in a permit office.
Seamless integration
We match rooflines, siding, trim and floors so your new space blends with the old — an addition that looks original, not bolted on.
Home additions Chicago & the suburbs
Bofran Builders proudly builds additions for homeowners across Chicago and nearby suburbs. We know the permit quirks, lot rules and architectural styles of each community — from city bungalows to suburban ranches — and tailor every addition to fit right in.
Don't see your neighborhood? Get in touch — we likely serve your area too.
Chicago Neighborhoods
- Lincoln Park
- Lakeview
- Wicker Park
- West Loop
- Bucktown
- Logan Square
- And more
Nearby Suburbs
- Glenview
- Evanston
- Oak Park
- Park Ridge
- Northbrook
- Highland Park
- And more
Built to last — and backed in writing
- 5-year warranty on all home additions, in writing
- 30-day post-project check-in to make sure everything is perfect
- Priority support if you ever need a repair
- Ongoing maintenance advice to protect your investment
Thinking about an addition? Get a clear, itemized number for your home.
What our clients say
"Our architect recommended Bofran Builders and we couldn't be happier. Frank and his team worked with us throughout building our new home, making excellent suggestions. Built on schedule despite permit obstacles — and more affordable than other contractors. The craftsmanship is phenomenal."
"The deck and staircase construction on a residential building was completed fast, under budget and with high quality. Even the city inspector was impressed with the workmanship."
"They did a great job replacing both support beams on our rooftop pergola — a tricky job with heavy materials in a tight space. I appreciated the attention to detail matching the existing accents and the timeliness to finish."
Home addition FAQs
Most Chicago home additions run $150 to $320 per square foot. A single-room bump-out is typically $150–$300/sq ft, a second-story addition $200–$400+/sq ft, and a kitchen extension $250–$500/sq ft. As a rule of thumb, a 500 sq ft addition lands between $75,000 and $150,000 depending on type, finishes and foundation work. Try our cost calculator for a number tailored to your project.
On average, Chicago home additions take 3–6 months from planning to final walkthrough. Garage additions and sunrooms can finish in 4–8 weeks, while second-story additions usually take 12–20 weeks. We break every project into three phases — planning (1–2 weeks), permits and final details (2–4 weeks), and build (8–16 weeks) — so you always know the timeline.
Yes. Chicago building codes require permits for most additions and major structural work, and fees typically range from $500 to $5,000. As your general contractor, we manage all permit applications, drawings and inspections so your project stays on track and fully up to code. Read more about why permits matter.
In most cases, yes. For room additions, bump-outs, garage and attic conversions you can usually remain in your home throughout. Larger projects like second-story additions may require temporarily relocating part of the household during the most intensive phases. We plan the sequence to minimize disruption and seal off active work areas to keep the rest of your home livable.
A well-built addition can increase property value by roughly 50–75% of its cost, and additions in high-demand Chicago neighborhoods often recoup more. Adding a bedroom, a bigger kitchen or a primary suite is one of the most reliable ways to raise resale value — while letting you stay in the home and neighborhood you love instead of buying a larger property.
We build the full range: room additions and bump-outs, second-story additions, kitchen and bathroom extensions, primary suite additions, 3- and 4-season sunrooms, garage additions and conversions, attic conversions, rear extensions, basement finishing, and ADUs / in-law suites. Browse them all in the addition types section above.
Start with how you want to live, your lot, and your budget. Out of room on your lot? A second story keeps your yard. Need just a bit more in one room? A bump-out is the most affordable option. Want flexible or income-producing space? Consider an ADU or garage-top suite. We'll walk your home, talk through the options, and recommend the best fit during your free consultation. For the full sequence, read how to plan a home addition.
It's easy. Call us at (773) 969-9097, fill out our online form, or email bofranbuilders@gmail.com. We'll schedule a consultation to discuss your project and provide a detailed, no-obligation estimate.
Ready to add the room you need?
Tell us about your home addition and we'll reach out within one business day with next steps and a clear, itemized estimate — from a Chicago contractor building since 1999.
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