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What is one of the first features you notice when looking at a house? The Windows -

Windows should be both energy efficient and appealing to the eyes.

At Contractors Building Supply our dealers will help you find the  best window for your home without your money flying out of it.

Call today, 231.378.2936, for a free estimate on one window or for an  entire house.

Thermolock Manufacturing started out as a small local window manufacturer in Northern Michigan. As the demand for high quality vinyl windows increased, Thermolock expanded its distribution to include Ohio and Indiana.

Today, Thermolock has moved its manufacturing headquarters to Cincinnati, Ohio, where it manufactures windows and doors out of a state of the art 100,000 square foot factory. 

Thermolock Vinyl Windows & Patio Doors can be purchased through distributors from Pennsylvania to Kansas and beyond.

The increasing demand for unique high quality windows will carry Thermolock into  the future.

Energy Savings is the hallmark of window performance and Thermolock takes its commitment to providing energy efficient products very seriously.

Here's how Sherwood windows work for you to save energy. First, Sherwood products are designed with performance in mind. Sherwood uses the highest quality PVC Vinyl and energy efficient multi-chambered designs from Veka, a world leader in the window industry. Sherwood windows meet industry performance standards set forth by independent agencies like the American Architectural Manufacturers' Association (AAMA) and the National Fenestration Ratings Council (NFRC).

Window Info


Thermolock - Hallmark Vinyl Replacement Windows Literature
Thermolock - Hallmark PRO Professional Series Literature
Sherwood Custom Wood Replacement Windows & Patio Doors