Room Additions in Central Illinois
Moving is expensive, stressful, and means leaving a neighborhood and community you already know. Most homeowners across Tremont, Pekin, Morton, Washington, and the greater Peoria area don't actually need a new house actually they just need more space in the one they already have. A room addition built by Mathes Construction gives you exactly that. We've been building additions onto existing homes across Tazewell and Peoria counties since 1977 and bedrooms, sunrooms, family rooms, home offices, and more and every addition we build is designed to tie into your existing structure so cleanly that it looks like it was always part of the original house. No subcontractors, no corner-cutting on the structural work, and a written estimate before a single nail gets driven.
WHY CHOOSE MATHES CONSTRUCTION FOR YOUR ROOM ADDITION
A Room Addition That Looks Like It Was Always Part of Your Home
Adding onto an existing home is one of the most technically demanding jobs a residential contractor can take on. It's not just framing walls and putting up drywall. You're tying into an existing foundation, matching rooflines, integrating with existing electrical and plumbing systems, and making sure the new space performs the same way the rest of your house does in a Central Illinois winter. Get any of that wrong and you end up with a room that feels cold, looks like a tacked-on afterthought, or worse has structural issues that show up years later. Mathes Construction has been building room additions across Tremont, Pekin, Morton, Washington, Bartonville, East Peoria, and the greater Peoria area since 1977. We know how to read an existing structure, plan the addition properly, pull the right permits for Tazewell and Peoria counties, and build something that adds real square footage and real value to your home without looking like it was glued on as an afterthought.
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Foundation, framing & roofline integration
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Electrical, plumbing & insulation in-house
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Permits handled for Tazewell County
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Room additions across 8 IL cities
What Goes Into a Room Addition And Why It Matters
A lot of homeowners in the Peoria area get surprised by how much planning goes into a room addition before construction even starts. You need a foundation that ties into the existing one properly. You need a roofline that sheds water correctly and doesn't create ice dams in a Central Illinois winter. You need electrical that connects to your existing panel without overloading it, and insulation that meets current Illinois energy codes. Then there are permits like Tazewell County and Peoria County both have their own requirements, and skipping that step causes serious problems when you go to sell the house. At Mathes Construction, we handle every part of that process. We've been navigating local permit requirements and building codes across this area since 1977, and we don't hand that responsibility off to the homeowner to figure out on their own.
Room Addition Projects We've Built Across Central Illinois
Over nearly five decades, we've built room additions of all kinds for homeowners across Tremont, Pekin, Morton, Washington, Bartonville, East Peoria, Peoria, and Mapleton. Growing families who needed an extra bedroom but didn't want to uproot their kids from their school district. Empty nesters who finally had the chance to turn unused space into a proper home office or sunroom. Homeowners in older Tazewell County houses who needed to expand their living room or add a mudroom because the original layout just didn't work for modern life anymore. Every one of those additions was built by our own crew, tied properly into the existing foundation and roof structure, permitted through the right county channels, and finished to match the rest of the house inside and out. When we were done, the addition didn't look like an addition. It looked like the house was built that way from day one.
Structural Work Done Right
Room additions live or die on the structural
details like foundation ties, roofline integration,
load-bearing wall work. We've been handling
the structural side of additions across
Central Illinois for nearly 50 years.
Nothing gets glossed over.
Permits & Code
We pull all permits required for Tazewell
and Peoria county room additions and make
sure every part of the build meets current
Illinois residential code. You won't have
a problem when it comes time to sell or
refinance your home.
We Serve in 8 Cities
Mathes Construction serves on Tremont, Pekin, Morton, Washington,
Bartonville, East Peoria, Peoria, and
Mapleton so if you need more space added
to your home anywhere in Tazewell or
Peoria County, Mathes Construction is
the crew to call.
SERVICES WE OFFER
Everything We Build & Remodel
From the ground up or a single room refresh. Here's what Mathes Construction handles across Central Illinois.
Mathes Construction provides Full-service home remodeling across Tremont, Pekin, Morton and surrounding areas. One crew, one contractor, start to finish.
- Interior & exterior remodeling
- Whole-home or single room
Mathes Construction redesign and rebuild kitchens across Central Illinois with smart layouts, quality materials and work that holds up for years.
- Full kitchen gut & rebuild
- Cabinets, countertops & fixtures
From a simple refresh to a complete bathroom renovation with clean work, solid materials, no shortcuts and done right the first time.
- Tile, vanity & fixture upgrades
- Full bathroom gut & renovation
Need more space but love where you live? We build seamless additions that match your home's existing structure and style across Tazewell County.
- Structural additions & expansions
- Matched to your home's existing build
Mathes Construction build Durable, low-maintenance decks and patios built for Central Illinois weather and designed around how you actually use your outdoor space.
- Wood, composite & custom builds
- Multi-level & ground-level decks
Custom-built pergolas that add shade, structure, and real curb appeal and we built to hold up through Illinois seasons and look great doing it.
- Freestanding & attached pergolas
- Custom size, style & material options
ABOUT OUR ROOM ADDITION WORK
Room Additions That Add Space Without Adding Headaches
The biggest mistake homeowners make when hiring for a room addition is treating it like a standard remodeling job and going with whoever gives them the lowest number. Additions are different. They involve your home's structural integrity, your existing foundation, your roofline, and your utility
systems and when those things aren't handled by someone who genuinely knows what they're doing, the problems don't show up during construction. They show up two winters later when the new room is drafty, or five years later when you're trying to sell and the home inspector finds work that was never properly permitted in Tazewell County. Mathes Construction has been building room additions onto existing homes across Tremont, Pekin, Morton, Washington, Bartonville, and the greater Peoria area since 1977. We understand how older Central Illinois homes are built, where the structural load points are, and how to tie a new addition into an existing house so that it performs properly in every season like not just looks good on the day we hand you the keys.
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Foundation & roofline
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Insulated for Central Illinois winters
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Fully permitted
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Room additions since 1977
Frequently Asked Questions
Questions About Room Additions in Central Illinois
Adding onto your home is a big decision and most homeowners have a lot of questions before they start. Here are the honest answers to what we hear most from people across
Tremont, Pekin, and Tazewell County.
Still Have Questions?
We’re here to help you!
How much does a room addition cost in Central Illinois?
Room additions vary more than almost any other project because the scope can be so different. A basic bedroom addition might start around $40,000–$60,000. A larger family room or sunroom addition with more complex roofline work, full electrical, and HVAC integration can run $80,000–$120,000 or more depending on size and finishes. We won’t quote you a number until we’ve walked the property, looked at your existing structure, and understood exactly what the addition requires. That’s the only way to give you a number that’s actually accurate.
Do I need a permit for a room addition in Tazewell or Peoria County?
Yes and always. Any structural addition to a home in Tazewell County or Peoria County requires a building permit, and the work needs to be inspected at key stages of construction. We handle the permit process for every addition we build. Skipping permits on an addition is one of the most expensive mistakes a homeowner can make and it creates serious problems when you refinance or sell the house down the road.
How long does a room addition take to build?
A straightforward single-room addition typically takes 8–12 weeks from permit approval to finished interior. Larger additions with more complex structural work, custom rooflines, or full HVAC and plumbing integration can run 14–20 weeks. Weather plays a role in Central Illinois too and we plan project timelines around it so foundation and framing work isn’t done in conditions that will affect the quality of the build.
What types of room additions do you build across Central Illinois?
We build bedroom additions, family room additions, sunrooms, home office additions, mudrooms, and expanded living areas for homeowners across Tremont, Pekin, Morton, Washington, Bartonville, East Peoria, Peoria, and Mapleton. If you’re in Tazewell or Peoria County and need more space without moving, give us a call.
Have Any Questions?
Whether you're planning a remodel or just exploring your options. Reach out & we'll get back to you promptly.
Let’s Work
Your Trusted Partner in Central Illinois Construction.
From Tremont to Peoria and across Tazewell County, Mathes Construction is ready to bring your project to life with honest pricing, real craftsmanship and decades of local experience.
Phone Number:
(309) 349-4342
Opening Hours:
Mon-Fri: 08:00 - 17:00 Sat-Sun: Closed
Office Location:
8600 Dillon Rd, Tremont, IL 61568