Room Additions
Create More Space with a Room Addition
If your home feels tight but you love where you live, a room addition might be the answer. We help families across Spring Hill and the Kansas City area add space that blends beautifully with what they already have. From second stories to sunrooms, we build additions that feel intentional and improve everyday living.

We are known for delivering projects that look like they have always been part of the house. Our team matches rooflines, materials, and finishes so your new space feels seamless. With over 16 years of experience, we bring the right mix of creativity, craftsmanship, and clear communication.
What We Build
Room additions come in all shapes and sizes. We design and build guest rooms, master suites, sunrooms, bonus rooms, kitchen expansions, and even second-story additions. Whether you need more space for family, hobbies, or everyday function, we create layouts that work with your lifestyle. Every detail is planned to align with your home’s original style and structure. From matching rooflines and siding to seamless interior finishes, your new space will look and feel like it has always been there.
Our Process
We start with a consultation to learn your goals, layout needs, and timeline. Then we design the space, secure permits, and begin construction. Our team manages everything from foundation to final trim, keeping you informed throughout. Once the work is complete, we walk through the space together, handle final details, and provide a warranty for lasting peace of mind.
Proven Craftsmanship, Personalized Service
Local Experience
We’ve been building in Spring Hill and the Kansas City area for over 16 years. We know the codes, climate, and what works best for local homes.
Seamless Design
Our additions are crafted to match your home inside and out. Rooflines, materials, and finishes are carefully chosen for a natural fit.
Fixed Pricing
No surprises here. We offer clear, upfront pricing so you can plan with confidence and avoid unexpected costs.
Start-to-Finish Service
From design to final walkthrough, our team handles every step. You work with the same crew the whole way through.
Trusted by Local Families
We are a local team with over 16 years of experience in room additions and remodeling across Spring Hill and the Kansas City area. You work with the same trusted crew from start to finish. Our fixed pricing keeps things clear, and we treat your home with care and respect. If you are ready to add space that fits your lifestyle, contact us today to schedule a consultation. We are here to help you plan with confidence and build with quality.
See Why Homeowners Recommend Us

"Their workmanship and attention to detail were spot on!"
Wow, Allen Building SP. did a fantastic job for us. Lincoln and Mike are the best! Their workmanship and attention to detail were spot on! If we had concerns they were addressed right away. We have recieved so many compliments on our bathroom. It looks beautiful and functions perfect! Thanks Trae
Doug S
Lenexa, KS

"Everyone is trustworthy, friendly, and most of all, very talented in their area of expertise"
This is our second time to use Allen Building Specialties for a remodel. Trae has a gift for choosing good people to work with on the team. Everyone is trustworthy, friendly, and most of all, very talented in their area of expertise. We absolutely love every room they remodeled from 2 bahtrooms, the kitchen and family room. They are easy to work with and stay on schedule. We feel lucky to have found them!
Mike C.
Overland Park, KS
" I have referred 3 friends to Allen Building Specialties so far and all of them have had a wonderful experience, as well!"
We had a fantastic experience with Allen Building Specialties. Trae and his staff are friendly, professional and courtious. Our project was completed in a timely manner and his bid came below several other estimates we received. Trae has already completed 2 remodel projects for us and we are in the process of starting a third! I have referred 3 friends to Allen Building Specialties so far and all of them have had a wonderful experience, as well!
Kate M.
Overland Park, KS
" The end result is high quality and very reasonable cost. "
This company exemplifies honesty, expertise, and talent. The end result is high quality and very reasonable cost. Allen Building Specialties work is perfection and it was a joy to have them in our home. We have never said ALL of these things in one sentence about a single contractor before.
Kara H.
Lenexa, KS
"The quality of work was excellent and Trae and his crew finished within budget and ahead of schedule"
The professionalism of Trae and his colleagues is outstanding. We had Allen Building Specialties finish our basement. The quality of work was excellent and Trae and his crew finished within budget and ahead of schedule. We are extremely happy with the finished product and will look to use them again on future projects.
Ryan M.
Lee's Summit, MO
"We are THRILLED with our remodel and we actually ENJOYED the process!"
What sets Trae Allen apart from other contractors is 1) his adherence to the schedule and 2) his excellent communication system. Regarding communication, everyone involved in the project is on an email software system so there is total accountability and written proof of all orders and changes. We are THRILLED with our remodel and we actually ENJOYED the process! Not something you hear very often after a construction project!
Susan R.
"High quality work, by high quality individuals!"
High quality work, by high quality individuals! Owner Trae Allen & his team are as meticulous as they come. They finished our basement last fall and we love spending time in the added space!
Jake S.
"They were so professional and easy to have in the house "
Trae and his team did an outstanding job on our upstairs remodel. They were so professional and easy to have in the house that unlike during past experiences with other contractors, we didn’t feel “invaded”. The project was also completed on time. Our upstairs is now so beautiful that it’s an absolute pleasure to hang out up there with our kiddos. We’re looking forward to working with Trae again, when we tackle our master suite remodel.
Meg S.
"He is organized and was excellent in his communication."
Trae is professional and friendly. He knows his craft and cares for his customers. He is organized and was excellent in his communication.
Theresa
"I have received many compliments on the finished product and am grateful for this talented team that made it all come together."
Having complete trust in a team with your home and family is tough to find. With Trae and team, they made a kitchen remodel as seamless as it could be. Their attention to detail and quality craftsmanship was excellent. Their communication was timely and responsive. The invoicing process was detailed, organized and delivered zero surprises. I have received many compliments on the finished product and am grateful for this talented team that made it all come together.
Denise S.
"They did excellent work and we have received many compliments on our addition!"
Trae and his team were wonderful to work with! They were pleasant, professional, detail oriented, and facilitated our project with ease. Trae and his team added a front porch to our home and we could not have been happier with the outcome. They did excellent work and we have received many compliments on our addition! We would highly recommend Allen Building Specialties.
Sarah H.
"Trae and his team are friendly, trustworthy, and knowledgeable"
Trae and his team are friendly, trustworthy, and knowledgeable. They refinished our basement and their work is excellent; we are thrilled with the outcome. Having a contractor to work with all of the third parties involved was necessary and Trae ensured that everything was completed at the utmost level of quality. They completed the job within the timeline agreed to. I highly recommend them.
Kristen N.
"Everyone at Allen Building Specialties is exceptional and a pleasure to work with."
We have now used Allen Building Specialties for 4 projects and we couldn't be more pleased. After working with a couple other contractors and finding them very undependable and with poor workmanship, we finally found Allen Building Specialties. We have worked with Mike the most. Mike is the definition of going above and beyond what is required and expected. Everyone at Allen Building Specialties is exceptional and a pleasure to work with
Kristen N.
"Every person who showed up on the job was great and did wonderful work."
Allen Building Specialties transformed my outdated kitchen into my dream kitchen. Every person who showed up on the job was great and did wonderful work. I have received so many compliments on his work and recommend them to anyone who is looking for a remodel. You will not be disappointed!
Erin O.
"The best part for me - when he laid out the timeline he hit the mark."
Trae and his company did an outstanding job for us. He helped us with a commercial buildout of our coffee shop. Trae provided constant contact, mixed with ways to save on our overall buildout as we went along. The best part for me - when he laid out the timeline he hit the mark. No 2, 3, 4 weeks delay/time or cost overruns like you hear from time to time with other contractors.
Michael J.
"The finished product was exactly as we had pictured and the final cost was exactly as contracted!"
Trae and his company of professionals were a true delight! The remodel was as painless as possible for us, considering that we needed to be living in the house while the work was being done. The finished product was exactly as we had pictured and the final cost was exactly as contracted! Any remodel has unexpected issues, but all of these were dealt with promptly and professionally. Thanks to all of you at Allen Building Specilaties.
Ginny B.
"They were easy to work with, even when challenges came up."
Trae & his crew were recommended to us by a friend. They were very professional, helpful with design ideas & advice, and stayed on schedule. They were easy to work with, even when challenges came up. We've been very happy with the results & have highly recommended them to others looking to remodel.
Judy D.
"Trey was honest and up-front"
Would I recommend Allen Building Specialties? Absolutely! Not just for basement remodeling, but anything that required remodeling, additions, or renovations. I am glad I picked them to do the work and I would use them again.
"They did excellent work and completed it on schedule"
Trae and his team remodeled our kitchen. They did excellent work and completed it on schedule. Everyone he brought into our house was trustworthy, patient, competent, and easy to get along with. They kept the site very clean and structured their work so that we would be without a functioning kitchen for as little time as possible. They stayed completely within the bid except for a few extras we decided to add. Trae was here every day to check on progress and quality. He had some great ideas that looked great in the finished kitchen. We would highly recommend Trae and his crew!
"Our daughter absolutely loves it!!"
We received a recommendation from our realtor to use Allen Building Specialists for a small remodeling job for our home. Everyone involved with this company was very professional, timely, and did a wonderful job. The job involved confirming that a wall between 2 bedrooms was not load-bearing, the wall then removed, followed by patching the walls and ceiling between the rooms. Our daughter absolutely loves it!!
Jenny W.
"Could not be happier with the final product!"
Excellent contractor, very good communication, top notch experience! Will be using them for all of my projects. Trae and team are very professional. Could not be happier with the final product!
Anthony Marriott
"Any future projects we need, Allen Building Specialties will be the first and ONLY phone call we make."
Trae and his workers were great to work with. Trae is knowledgeable about the business and provided us options with our Master Bathroom Remodel. The foreman of our project, Mike, was incredible. His tile work was outstanding and meticulous. We could not be more pleased with the finished project. Any future projects we need, Allen Building Specialties will be the first and ONLY phone call we make.
Donna Z.
" I highly recommend Allen Building and would definitely use Allen Building Specialties again!"
We updated a house we had lived in for 27 years. We built a new fireplace at end, added hardwood floors, updated kitchen cabinets, updated ceiling, and lighting. Trae was wonderful. He was very professional, always returned my calls promptly, helped me to stay in my budget, was very patient as I made decisions and his skill and workmanship were beautiful. I did not have a decorator help, and I would show him pictures of what I wanted, and he always understood. He is honest and I trusted him completely. I highly recommend Allen Building and would definitely use Allen Building Specialties again!
Jan D.
"We were thrilled with the finished product!"
Trae, and his crew, removed a wall in our home, and built a new stone fireplace, creating a truly "open concept" between our kitchen and Great Room. Trae shared his knowledge and many good ideas....He and the crew were always professional and very courteous in our home. The project was done within the predicted scope of time and cost. We were thrilled with the finished product!
Bob and Carol J.
"Their workmanship and attention to detail were spot on!"
Wow, Allen Building SP. did a fantastic job for us. Lincoln and Mike are the best! Their workmanship and attention to detail were spot on! If we had concerns they were addressed right away. We have recieved so many compliments on our bathroom. It looks beautiful and functions perfect! Thanks Trae
Doug S
Lenexa, KS
Start Your Room Addition Today
Need more space but not ready to move? A custom room addition could be the perfect solution. Contact Allen Building Specialties, Inc. to schedule a consultation and start planning a space that fits your life and your home.
Room Addition Questions Answered
How long does a typical room addition take?
Most room additions take between 3 to 6 months, depending on size, complexity, and weather. We provide a detailed timeline before work begins.
Will the new space match my existing home?
Yes. We design additions to blend seamlessly with your current structure, matching materials, finishes, and overall style.
Do I need plans before reaching out?
No. We guide you from concept to completion, including layout planning, design, and permitting.
Can I live in my home during construction?
In most cases, yes. We plan work in phases and take steps to minimize disruption and keep your space safe.
Is financing available for additions?
We can connect you with trusted financing partners and help you explore options that fit your budget and timeline.
Upgrade Your Kitchen With Custom Remodeling
Is your kitchen feeling outdated or too cramped? We design and remodel kitchens that work better for how you cook, gather, and live. From open layouts to custom cabinets and quality finishes, we turn the most-used room in your home into a space you truly enjoy.