DSC_4321As your Columbus remodeling company, we know there is a significant push for energy performance upgrades to existing homes. An important target is often the windows. Old single-glazed windows have such low thermal resistance that their effect on the overall thermal resistance of the walls can be staggering. Improving the performance of the window is therefore central to the goal of reducing the energy consumption of the existing building.

We want to provide information and guidance about rehabilitating, retrofitting, and replacing wood windows in a residential renovation. Deciding which window measure will be most appropriate for the project depends on several factors, including current conditions, desired appearance or aesthetic goals, energy performance goals, cost, disruption to occupants, durability risks, historic requirements, and any other project goals or requirements.

A variety of window technologies can improve window energy efficiency, including gas fills, low-E coatings, and high performance frame options. How these technologies affect a window’s energy performance depends on the sum of all parts. This is where whole window energy ratings help, accounting for the combined effect of glazing, spacers and frame (thermally improved).

Glazing Types

Traditionally, windows have been made from clear glass, but advanced technologies have significantly improved the thermal performance of glass.

Gas fills

Gas fills improved the thermal performance of insulating glazing unites by reducing the conductance of the air space between the layers.


The layers of glazing in an insulating unit must be held apart at the appropriate distance by spacers. Warm edge spacers have become increasingly important as manufacturers switch from conventional double glazing to higher performance glazing.

Frame Types

The material used to manufacture the frame governs the physical characteristics of the window, such as frame thickness, weight, and durability. It also has a major impact on the thermal characteristics of the window.

Emerging technologies

Most of the emerging glass technologies are available or nearly on the market. These include insulation-filled and evacuated glazings to improve heat transfer by lowering U-factors.

  • Glass
  • Dynamic Windows
  • Building Integrated Photovoltaics
  • Measuring Performance: U-Factor

The rate of heat loss is indicated in terms of the U-factor (U-value) of a window assembly. The lower the U-factor, the greater a window’s resistance to heat flow and the better its insulating properties.

Low U-factors are most important in heating dominated climates, although they are also beneficial in cooling dominated climates. ENERGY STAR provides recommended U-factors for your climate. If you have a project in your home (windows or otherwise) that needs some attention, we will gladly come out and survey your residential renovation, and work together to help make your home the best it can be!

We currently build in Westerville, Worthington, Whitehall, Upper Arlington, Powell, Pickerington, New Albany, Lancaster, Hilliard, Gahanna, Dublin, Bexley, Columbus and all of Central Ohio.