Windows and doors aren't just about decor and design. They also help you stay warm in winter and cool in summer. Best of all, the right windows and doors can save on energy consumption. That's money in the bank for homeowners, and a better environment for us all. CaneProof: Premium Energy Efficiency Our uPVC window and door profiles delivers some of the best energy ratings in the industry. Why? Because the exclusive multichamber design has more air space than comparable vinyl windows. The added air space acts like insulation, reducing noise and keeping your home comfortable all year round.

Energy Ratings Guide

Ratings help you compare whole-product energy performance.

Terms
Here are 3 energy performance properties that describe how energy is transferred and how performance is quantified.

U-factor: assesses resistance to heat flow. Quantifies the insulation value of a window assembly (glazing, edge effects, sash, and frame) and can depend on weather conditions. The lower the number, the better the performance.

Vinyl (uPVC) windows and doors outperform other types.

Source: Residential windows: a guide to new technologies and energy performance,
            John Carmody et al., 2nd ed., 2000.

SHGC (solar heat gain coefficient): relates to the amount of heat transmitted by sunlight. The lower the rating, the less heat is transmitted.

Infiltration: Heat loss and gain by air leakage through cracks or joins in the window assembly. The lower the number, the better the performance.