Constraction reviews in Boulder, Colorado

We had Alex rebuild the curved step on our deck. He was professional, friendly and prompt, from the initial visit and estimate, continuing through the entire construction process. It's clear he cares about doing quality work and we were very pleased with the result. He left things tidy at the end of each day, and at the end of the project he cleaned up entirely. Having worked with our share of contractors, I can tell you Alex is one of the good ones, and can wholeheartedly recommend him.

Alex is very professional and knowledgeable. He reinforced my deck that was sagging due to the weight of my hot tub. He kept me informed throughout the project.
Alex is meticulous and easy to work with. His associate, Jake compliments Alex and they work well as a team. I highly recomend Cosman Construction.

Alex built us a new back deck with cable railing to better enjoy the view. The work was very high quality and completed quickly. Alex was responsive to all the minor requests and questions we had. You get what you pay for - highly recommend.

I used Cosman Construction for a deck install, fence install, and some other landscape work. They are not cheap but you absolutely get what you pay for. The final project is beautiful and we are completely satisfied. Alex and crew were very professional and knowledgeable. They paid meticulous attention to quality and detail and have the tools and expertise to make sure everything is done correctly - they removed an old concrete deck slab, sunk concrete for a deck, built a composite -topped deck, graded much of the yard with new dirt, and built a new privacy fence. Throughout they were great with communication - always on time and in contact. They explained all aspects of the project and went above and beyond to make sure we got exactly what we wanted.

I had an exceptional experience with Alex and the Cosman Construction team. Their pricing was reasonable, and they provided practical recommendations on what needed to be done. They collaborated with me to determine the best solutions within my budget for my deck remodel/repair. Their efficiency was impressive, and the results were excellent. Alex is very knowledgable about deck and fence construction and has a great eye for aesthetic beauty as well. I highly recommend Cosman Construction and will unquestionably enlist their services for my future projects.

Alex and crew built a small deck in front of my kitchen and office entrances. They also built planter boxes, a fence and gate, and laid a concrete pad and sidewalk for the hot tub.

The quality of their work was very high. I expect that from a Boulder contractor. The thing that was most impressive and rather surprising to me was the flexibility and positive attitude Alex displayed throughout the course of the job.

When I would change the plan, or ask him for suggestions about how to make it "more the way I imagined it" the morning they were about to start on a new aspect, Alex went with the flow, made suggestions and stayed positive in a way I've rarely if ever seen in my experiences of spending hundreds of thousands of dollars on home improvement.

Could not recommend Cosman Construction highly enough.

I recently had Cosman Construction build a brand-new deck for my home, and I couldn’t be happier with the results! Their attention to detail and craftsmanship are second to none. From the very first consultation, they communicated clearly and consistently, making sure every question I had was answered.

The deck itself turned out beautifully—sturdy, stylish, and exactly what I envisioned. On top of that, they worked efficiently, stayed on schedule, and were respectful of my property throughout the process. If you’re looking for a reliable, high-quality construction team for your next project, I highly recommend Cosman Construction!

Cosman Construction and their team are amazing to work with! Super creative, responsive, well priced and fast! We had a small project and they were able to quote it and complete it within a week. I’m sure they won’t always be able to achieve that, so no promises for you ;) They took their time and did the installation perfectly and it looks so classy. Thank you Alex and crew. I will forever be grateful.

We had the best experience with Alex and his crew, Michael and Jay!! They really are great people and fun to spend a few weeks with! The three are highly professional, very knowledgeable, and create beautiful decks together. Alex spent lots of time with us working through our questions and concerns while explaining the process and his recommendation on how to proceed. He was there for us every step of the way and nothing was too much to ask. I can't recommend Cosman Construction enough. Great product! Great people! We love our new outdoor living space! Thank you, Alex Cosman!

We have a new deck thanks to Cosman Construction! Alex did an excellent job from start to finish; It looks great from the black railing on top to the beautiful hardware anchoring the posts to the foundation at the bottom. In fact, the entire support structure underneath exudes strength and the details of fine craftsmanship are pleasing. We appreciate Alex's attention to detail, his patience as we decided what we wanted, and the quality of the materials used. He gave us lots of options in both design and materials. The team/crew on the job were steady workers and great to have around while the work was being done.

Alex and his partner did a stellar job replacing a porch stoop and step with something that was much better looking, Class-A fire-resistant, and would withstand an earthquake. They repaired pre-existing water damage to adjacent house joists and improved the flashing so the surrounding area was as sound as the stoop itself. It's only a 4x6' stoop but with a steel understructure secured on concrete pylons anchored about 18" into the ground. Cosman does not do flimsy. It also looks good. They show up on time, are flexible with design decisions, and don't cut corners for the sake of expedience.

Extremely satisfied with our experience with Cosman Construction! Alex is fantastic to work with...very personable, professional, responsive, and transparent. The quality of the work is amazing...high standards for engineering and structural integrity plus an eye for beauty and aesthetics. We love our beautiful new deck!

They build beautiful decks and are great to work with! They made the design phase really easy as well. We had a unique project with some timing issues created by waiting on xcel to relocate a line before we could finialize the deck. Alex was very patient and flexible with the time delay that had nothing to do with his crew or scope of work, and finished up the deck as soon as possible. The look and feel of our new deck is amazing!