Our Story

Mile High Designs was formed in 2005 as a small two man subcontracting crew. With a lot of hard work, we’ve grown into a highly rated family business with a team of valued employees and trade partners ready to transform homes throughout the Denver metro area and mountain communities along Hwy 285 and I-70.

In 2019, after a few cases of mistaken identity and a lot of consideration, we started transitioning to doing business as Highline. There are so many ‘Mile High’ service companies out there and we don’t want to be mistaken for other less than stellar competitors.

But don’t worry, Highline is still delivering the same award winning service that made Mile High Designs thrive. Contact us today and let us know how we can help you.

Our clients love us but we love them more.

Highline: Design & Build
Based on 7 reviews
powered by Google
16:45 01 Oct 21
Ray, Ben, and the entire team at Mile High were extremely professional, easy to work with, and did... extremely high quality work! We are extremely happy with our new deck and deck cover. I would highly recommend them!read more
Ashley Lercara
Ashley Lercara
01:10 14 Oct 20
Great company and great service! I moved into a new house and the deck desperately needed to be... replaced. I contacted Mile High Designs and Ray was very flexible and got me everything I needed for the project. Everyone was professional and made sure everything was done in a timely manner. A special shoutout to Christopher who patiently dealt with my constant questions every step of the way. My deck turned out amazing and I am so happy!read more
Steve Knapp
Steve Knapp
05:44 02 Jul 20
It has been about a year since our project was finished and we are still thrilled with it! Ray was... great to work with, offered many ideas and communicated well through the entire process. His crew was knowledgeable, hard working, and very efficient. They tore down our old wood deck and built a new composite one, adding a gabled deck cover and railing. We love the solid wood beams, cedar plank ceiling, Trex transcend decking (which has not scratched), and low voltage lighting that gives everything a great look after dark. It is our favorite place to go and has added so much value to our home. We highly recommend this company. Thank you Ray and your team for doing such an amazing job!read more
Riley Walker
Riley Walker
17:00 15 Jan 19
Ray and his team built a deck for us and it turned out great. The project was on time, on budget,... and hassle-free. We liked their work so much, we hired them for two more projects.read more
David Cates
David Cates
16:20 20 Aug 18
Quality workmanship at a fair price.
Dave Cates
Dave Cates
16:44 30 Oct 16
This company is the best. They have a lot of professional knowledge and get it right the first time.
Next Reviews
Highline by Mile High Designs
Based on 6 Reviews
Rachael D.
Rachael D.
2021-10-01 22:57:44
Selling Real Reviews for Your BusinessGuaranteed confidentiality and quality of reviewsAll accounts of real users, with reviews and friendsYelp accounts...
Joni J.
Joni J.
2021-05-18 10:22:52
Selling reviews Yelp, googleWe write reviews, promote your companiesGuaranteed confidentiality and quality of reviewsAll accounts of real users, with...
Rexford H.
Rexford H.
2020-03-26 19:07:52
The bid process of getting a new deck was frustrating and exhausting to say the least. I recieved 8 bids ranging from 28k to 65k all giving me a wide...
Cooper S.
Cooper S.
2017-12-10 12:56:18
I've been looking for an honest, straight forward and talented contractor and the name Mile High Designs kept coming up. Took a look at the website and...
E M.
E M.
2013-03-17 11:09:39
Ray Dertz and Mile High Designs completed a 500 sqft covered patio to our home in the Summer of 2012. From the beginning of the project to months after,...

Best of Houzz 

Since 2016
Ray Dertz in Littleton, CO on Houzz
Ray Dertz in Littleton, CO on Houzz

Check out what we're building in your neighborhood.
What can we build for you?

Testimonials from our wonderful clients.

Thoughtful design. Thoughtful customer service.


Complimentary project management software on all projects.

  • 24/7 access to project details on Buildertrend site and app
  • Secure messaging
  • Progress photos
  • Scheduling calendar


The Highline Team

Ray Dertz

Owner &

General Manager


On-site Project Leader

All of our employees are covered by workers comp coverage.

We're open for business!

What can we do for you?



Take advantage of unanticipated openings in our schedule. Our guys are finishing up some of our projects faster than anticipated and leaving small gaps in our start schedule. We have openings for new clients who are ready to begin their projects before spring. These limited openings are first come, first served and won’t last long. 
INTERIOR HIATUS: We are focusing on outdoor projects and are not currently accepting interior project inquiries. Sorry for any inconvenience.

Highline: P.O. Box 631596 Littleton, CO 80163

P: 303-503-5597

F: 720-362-5214