New Window Installation Company servicing Valparaiso, IN. Energy Efficient Replacements is a leading window installation company with over 14 years in business. Get comfortable today by replacing your leaking windows and doors. From the moment your new windows are installed you will notice a huge difference in comfort and noise reduction. Choose from many window styles including: Double Hung Windows, Sliding Windows, Fixed / Picture Windows, Casement Windows, Awning Windows, Bay Windows, Bow Windows and Hopper Windows. No matter the style and configuration you are looking for, Energy Efficient Replacements has the answer.