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Home - FireFly Builders
Free Estimates: 605.881.5981

Firefly Builders is one of South Dakota's premier General Contractors.

We specialize in new custom homes, AG and commercial buildings along with many other construction projects in the Black Hills and surrounding area. We have been building for over 20 years and have a well-known reputation for our attention to detail.
As a premier builder, we want you involved in every step of the building process; from the initial design, to the completion of your new project. It is our mission to assure you are happy with your new project.
Let us help you make your project a reality!



  • General Contracting
  • New Construction
  • Renovations
  • Concrete
  • About FireFly
  • generalcontracting image1Firefly Builders provides general contracting, design-build, and construction management services that exceed the very high expectations of our clients. We provide the best quality, value, and client experience through every step of a project, we work closely with our client, designers, subcontractors, and vendors. We do this to create teamwork on each and every level, but when it comes to our commitments, we don’t compromise.

    Firefly Builders is a family-oriented company, and our clients are our extended family. In fact, many of our current projects are with clients we have served in the past. They know they can rely on our commitment—to safety, quality, value, teamwork, efficiency, and excellence in all our services and products—because we earn that trust every day. From foundations or renovations to design assistance and full-service construction of complex multiuse projects, we tailor each project to the individual needs of the client.

    As a general contractor, we like to "get our hands dirty". We take a "hands-on" approach to every project, maintaining the highest safety and quality standards in the contracting and remodeling business. We would like you to consider us your one point of contact for any details or issues involved with your remodeling or building project; consider us your "one-stop-shop". We can provide all of the services and materials needed to complete the project, plus we will offer support at all phases of the project. We have the resources to address any issues, assist special needs of the client and provide continuous budgeting assessments throughout the duration of your project.

    Our job as General contractors is not only to construct and remodel; We will also assist you by preparing a detailed schedule for the project, constantly evaluate our performance and approach, and always seek better alternatives to serve you.

  • remodels image1

    Firefly specialized in designing and building affordable new construction of all sizes and budgets throughout the Black Hills area.

    Building a home is one of the most important investments of your hard-earned money. Equally important are the many hours of your time dedicated to realizing your dream. That’s why to us, its paramount that we have your faith and trust as your builder.

    Not all new home construction is expensive, any style home can be custom built, from a cabin in the woods to a mansion with all the latest features. We can tailored to the specific needs of the customer. We can rely on our many years in the industry to give insight and guidance through the custom design process helping you design a unique floor plan or finding a stock plan.

    Have faith in our knowledge and experience to deliver a truly unique home building solution from start to finish.

  • remodels image1We are a full-service home remodeling company with over two decades of experience. There’s no project too big or too small. Each renovation and client is important to us and deserves quality craftsmanship. We take pride in transforming renovations into living spaces our clients are excited about.

    Home improvement projects should add several kinds of value, 2 in particular – personal enjoyment and return on investment when you decided to sell your home. Firefly Builders will help you make the best, most effective upgrades that fit your budget and timeline.


    Take the heart of your home and make it special. After all this is where friends and family gather, make it something everyone loves by updating appliances, swap out cabinets, update fixtures or new custom flooring.


    Your bathroom should be a place you want to spend time in. Take away stress with a luxury spa feel by adding private vanities, heated floors, or a whirlpool tub.


    Finishing your basement is one of the fastest and most cost-effective ways to add and entirely new story to your house. It can greatly increase your quality of living by adding more bedrooms or a great place to entertain guests.


    Need more space, but love where you currently live? Adding an addition not only increases your square footage but also adds value to your home without having to change what you already love about your home.

    Exterior Fixes

    Give your home an exterior home makeover. Change your curb appeal by updating primary focal points with a new porch or energy efficient windows.

  • concrete image1Simply the best concrete paving contractors in South Dakota.

    Concrete Repair, Removal & Replacement

    Concrete repair, removal and replacement projects are another part of our specialty. We can fill minor cracks in concrete or saw-cut, remove, and replace sections of concrete. During concrete replacement projects, we provide amenities such as bollards, islands, drains and footings. We also offer concrete finishing and specialty services including pavement markings and striping.



     We perform most concrete construction projects including:

    • Parking lots Walkways
    • Slabs
    • Driveways
    • Foundations
      • Wood
      • Block
      • Poured
      • ICF

    We also do specialty concrete construction including:

    • Gutters
    • Curbs
    • Trench Drains
    • Catch basins
    • Dumpster pads
    • Sidewalks Islands
    • Loading docks Ramps.





    Decorative Concrete

    We are experts in stamped, colored, or exposed aggregate concrete. This includes decorative patios, walkways, sidewalks large or small. Firefly can remove and dispose of all your old concrete materials and we take great care in making sure to avoid damaging lawns and landscaping. We have many years of experience working with tight construction schedules and coordinating our work with other contractors.





  • whyus image1Firefly Builders Inc. was formed in South Dakota with only one thing in mind; to be one of the top general contractors in the Midwest.

    After many years we can proudly say we have achieved great success by providing our clientele with exceptional work and outstanding customer service on their new construction and renovation needs.

    Our expertise makes us uniquely qualified to assist you with your project needs. We've built a reputation of hard work and excellence by helping customers like you reduce costs and improve quality.

    We are committed to work only with the best materials and the best team of subcontractors in order to ensure that all of our customers’ goals are fully met, and their needs fulfilled! We also provide services to other major General Contractors who agree on the fundamental fact that the best way to be successful and provide their customers with the best quality and service is to hire professionals.

  • Our Approach

    Our Approach

    As a builder, Firefly provides single-source accountability throughout the entire building process. We understand that building the home of your dreams is a delict balance of imagination and preparation. We work closely with you to zero in on the design characteristics of your project while providing all the requirements you desire. We can help you design a home that is great looking, practical, functional, and affordable.

  • Our Flexibility

    Our Flexibility

    Sometimes a home improvement project, for whatever reason, needs to be taken in steps. Maybe your dream patio just needs the concrete poured this season and the deck will be added the next year. In any situation, we want to work with you, your budget, and your timeline. Firefly Builders understands this process and will work with you in planning the best scenario. We handle all phases of home improvement. No project is too big or too small. Contact us today to talk about your new project and how we can help.

  • Why Work with Firefly?

    Why Work with Firefly?

    Our goal is to change the home building industry, to make a difference in our clients lives and to provide an unmatched building experience. We do this by providing the highest quality craftsmanship and by using the most innovative technologies. Our reputation is built on integrity, trust, and loyalty to our clients; we are proud to stand by that.

    Contact Us

Project Quote Request

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Contact Us

Wayne Koistinen - 605-881-5981
Larry Koistinen - 605-881-0844
Zach Lafontaine - 605-569-2092

Customer Testimonials

  • Firefly Builders, Inc is a great company to hire to build your new house. They get the job done in a timely manner and do an awesome job. We could not be happier with the service, quality, and the kindness shown by Firefly. It was an amazing experience and my new home looks great. We would recommend Firefly to anyone needing a General Contractor.

    Brandon and Karla Young

  • Pro Form Concrete, LLC has done business with Firefly Builders, Inc and found their Company excellent to do business with. Very professional, personable, and prompt, we found that they have a real understanding of the general contracting business as it pertains to the subcontractor & homeowner, realizing what information the subcontractor needs as it relates to what the home owner’s expectations are.

    Thanks for giving us your business!

    William Ritola – Owner - Pro Form Concrete LLC

  • My company Watford City Homes Inc. has been doing business with Firefly Builders, Inc for several years. They have been a great company to work with. Wayne the owner of the company is a man of his word. If he tells me something he stands behind it. Very rare in this day in age. I have not been able to find a problem they can’t help me out of. The last job Firefly did for me was 10 hours from the office. Wayne went way beyond what he was paid to do to help me. While his family sat in a hotel room he stayed an extra day just to help me and my customer with their new home. If you ever need a contractor to treat you like family, this is the company to hire. I will never forget the great job they have done for me.

    Shane Moran
    Managing Director
    Watford City Homes Inc.

  • Firefly re-sided my house recently. When I was looking for a contractor the lumber yard recommended them. I had heard of the company, but was tentative about hiring them since I did not know their work personally. On that one recommendation I hired them, and I am so thankful that I did!. The crew was polite, knowledgeable, and efficient. They were very good about keeping me in the loop regarding progress, and making sure I was satisfied. When they were conscientious about leaving the job site clean and picked up each night (it is amazing how many contractors do not do this!). They work HARD , and some long hours at times, to get the job done. Their quality was exceptional, and though they were not the cheapest, they were worth every penny! I look forward to using them for future projects and hope you will too!

    Rick Furnish