The Little Man Business, with Big Customer Service!



Building or Remodeling??

Shop first at your local Building Center!

Roundup Building Center provides personalized service for your construction and remodeling needs at all budget levels not found in "Big Box" stores.





About Us

We share your passion for building. And we welcome the opportunity to know and serve you better.

Thermo-Tech Windows


Thermo-Tech offers vinyl windows and doors in a wide array of standard sizes that make new construction a breeze. Or we can build replacement windows or doors for nearly any replacement project. No need to reframe. Simply order the size windows that you need, all the way down to 1/16th-inch increments. View more products...

Marvin Windows

Marvin Windows

Update existing space with replacement windows. Or add the perfect finishing touch with designer window and door hardware or other custom-crafted options, each ensuring that every element of your home is completely built around you. View more products...

Integrity Windows

Windows made with Ultrex components expand and contract at the virtually same minute rate as glass, so each window remains tightly sealed with no leaks, seal failures or stress cracks. It’s so strong, we have to use diamond-edge blades to cut the pieces to size. Imagine what that level of durability can endure in your home. View more products...

Integrity Windows

Larson Windows

Larson Storm Windows

Larson Storm Windows offer the best protection and best quality in the storm window market. From our high-tempered aluminum master frames and wrap-around marine glazing to our heavy-duty metal handles, you’ll know you’re getting the perfect combination of superior durability and beautiful style when you choose Larson storm windows for your energy efficient house. View more products...

Andersen Windows

With over 50% more clarity than our aluminum insect screens, virtually invisible TruScene® insect screens let more sunlight and fresh air in, while keeping even the smallest insects out. View more products...


Andersen Windows


Gerkin Windows


Gerkin Windows are sold and found in most parts of the Northern half of the U.S. and Canada. We have taken the initiative to continue company growth with new designs, and quality new products. This philosophy and commitment is the legacy of Gerkin Windows & Doors.