Locally Owned Window & Door Supplier Contemporary and Colonial Products


At 406 Window Co. relationships drive our business. These relationships are developed from our owner, Brian Reay, and his own personal beliefs that have been in the industry for 35 years. Brian started his career as a young man taking home construction classes at the Career Center in high school.

He worked at Knox Lumber for 15 years starting at the bottom working up to management. In 1995, Brian saw an opportunity to start 406 Window Co. carrying on his experiences in building homes, management training, and customer service over to the new business adventure. Montana Window & Door has been family based since the beginning. His wife, Robyn, has supported him in management and marketing throughout the years and continues to be involved. The Reays have three grown children: Lynde, Aaron, and their youngest Austin. All the children have grown up helping in some way with 406 Window Co. as they strive to be the best Billings window and door company!


Our loyal builders who know that building quality homes requires high value products at competitive pricing.


All of the colors of your Life!


The Highest Quality Doors in Billings, MT

Energy Efficiency

Most Energy Efficient Products available

Slider Window


At Alpen we custom manufacture super-insulating, thermally-efficient residential and commercial windows and doors utilizing a unique proprietary combination of component products, including lightweight suspended-film technology and a fully insulated fiberglass framing system.  Our American-made product is custom manufactured by experienced craftspeople driven by the utmost attention to detail and only the highest quality materials.

We have excellent windows to match Clawson Windows.  If you are looking to replace your Clawson Windows near Billings, MT, Sierra Pacific Windows will work great for replacing them.

  • Sierra Pacific is a vertically-integrated company
  • We own the forestland and manage it for sustainable growth
  • We process the wood in our sawmills
  • We convert the shop grade lumber from our sawmills to moulding and millwork (including window and door components) in our millwork facilities
  • We assemble the components from our millwork plants into top quality wood windows and doors in our window assembly plants
  • We ship the windows and doors to your jobsite on our trucks