OneSource Window Systems provides and installs Windows, Sliding Glass Doors, Terrace Doors, and Balcony Enclosures for Condominiums.  Our experienced installers and project managers are knowledgeable, efficient, clean and respectful, ensuring seamless transition to new, beautiful, energy-saving windows and doors.

Window Installation Service Columbia
Sliding glass doors services Columbia
Balcony Enclosures services Columbia


Balcony Enclosures

Sliding window repair

Frequently asked questions

Why Choose OneSource?

We are a customer service driven company that will always put your total satisfaction as our top priority.

What forms of payment are acceptable?

We accept personal checks, all major credit cards, and ACH electronic payments

Is there a deposit required?

Yes, a deposit of 33% of the total invoice is required with the approval of estimate.

When is the balance due?

Remaining balance due at completion of installation (typically 8-12 weeks from order date)

What is the warranty for the window(s) and door(s)?

Product warranties vary from manufacturer to manufacturer. Warranties will be provided, upon request

Will my sightlines change?

Your new windows or doors may vary slightly from the existing ones. Prior to ordering, all products receive approval by your condominium association to ensure consistency of architectural sightlines.

Will my Threshold (sill) height be different?

Sliding Glass Door threshold (sill) heights will vary from existing ones.

What is the warranty for labor?

OneSource will warranty the labor work for 3 years from date of installation.

Are screens included with my purchase?

Yes, screens are always included with the purchase of windows and sliding glass doors.

I’ve placed an order. When will installation begin?

Products typically ship to our warehouse within 8-12 weeks from the order date. We will schedule your installation once we have verified that all products have been received and are free from defects.

What if I have pets?

Please make arrangements to have them removed or isolated in another room.

What is the typical time frame for installing new window(s) and door(s)?

Typically, most installations can be completed within 1-2 days. Each opening will be completed the same day it has begun with no window or door opening left over night.

Do I need to do anything prior to installation?

Yes, the day before remove all blinds, curtains, and drapes. If you would like us to remove and reinstall; the fee is $75 per window, and $125 per door. To make arrangements please call (240) 755-0435. There should be at least 4 feet of space for our installers to work surrounding the opening.

Do I need to be home when you come to install?

If you choose not to be home during installation, please notify management/front desk to approve our entry into your unit.

Do you dispose of the old windows or doors?


Will you clean the new window(s) and/or door(s) before you leave?


If it is raining or snowing, will you still come to install as scheduled?

We may not work that day, depending on the severity of the weather conditions. If we need to reschedule, we will contact you with our next available installation date.

What is Low E glass

Low E glass has an oxide coating which is invisible to the eye but protects against UV rays which can burn your skin, fade carpets, and damage furniture. In the winter it reflects certain segments of the sun’s light back in to the home to keep it warmer and in the summer it reflects sun segments outside to stay cooler.

What does U-value mean?

It is a measurement of how well a window conducts heat. The lower the U-value the better the window insulates against heat transfer.

What does SHGC mean?

Stands for “Solar Heat Gain Coefficient” and represents the amount of heat from the sun allowed to pass through your window. The lower the SHGC value, the less of the sun’s heat that can pass through the window.