YES!! A drafty pet door that leaks air into or out of your home will raise your energy bill. Even more so if you live in a climate that has extreme hot or cold weather throughout the year. With cold weather right around the corner you might be looking for the best pet door for winter. Read this taken directly from the Energy Star website:
If your looking the best pet door for the winter months be certain to find one that seals and allows zero air infiltration. It is a fact that Freedom Pet Pass pet doors reduces air infiltration over 190% better than the competition and reduces thermal loses by 35%. An Energy Star home sealing engineer tested the Freedom Pet Pass against the worlds best selling pet door to find this out and more… read full report