What you need to know about piggybacking windows

When you hear the word piggyback it probably stirs up an image of two people, the first person being carried on the back of the second person. When talking about window installation the word piggyback should conjure up a similar image. Let me explain. Instead of people, envision your brand new window about to be installed, and the old windows entire frame is still in place. Your new window is then inserted and carried by your old windows frame, the very same window you wanted replaced. That doesn’t seem right to me, and is definitely not as carefree as getting a ride on a friends back. This brings up some concerning issues about piggybacking windows that everyone should remember when looking for new renovation windows.

This is how bad a window looks when the install process is Piggyback.

Breeze through windowWCW-Piggyback-768x1024

Issue 1 Responsibility:
When new vinyl windows are installed inside the old aluminum frame they are also piggybacked on the old windows installation. The installation of your old window could have been done over 40 years ago. Who is now responsible for your window and its weather seal? I personally don’t like basing window installation and weather proofing on someone else’s work who I have never met. In school that’s called cheating and cheating off of someone you don’t know isn’t very smart.

Issue 2 Glass Size:
Piggyback windows are measured to fit inside your old window’s frame, not the larger original window’s opening. This reduces the amount of glass in your new window. I always like my view to be as unobstructed as possible.

Issue 3 Window Efficiency:
When you piggyback your new energy efficient window, it is just covering up and hiding the old inefficient aluminum window. Does that seem like it would maximize your new window’s efficiency? In fact some sources say it is 20% less energy efficient.

Issue 4 Interior Trims AKA Vinyl Trims:
Piggybacked windows are measured smaller then your home’s full size window opening. On the inside this creates gaps on all 4 sides of your new sleek window. These gaps subsequently need to be covered up by bulky wood or vinyl trim reducing the space on your window sills.

Issue 5 The Coverup:
Remember the condensation that would built up on your old aluminum windows and you were constantly wiping up the moisture so it would not support the growth of mold? Once your new window encases and covers up your old aluminum window any condensation that occurs from then on is trapped and mold is free to grow. In 10-15 years there could be quite the science experiment hidden behind your window.


Don’t get me wrong I understand why piggybacking is done, because it is faster to install, easier to install, and it take less thought when measuring to install. However I don’t understand how this is beneficial for you, the homeowner. In fact this method of install only benefits the installer. If you are getting a quote from a company that is looking to piggyback your new windows make sure to get a free in home estimate from us, West Coast Windows. We only quote the full removal of your old windows to maximize the installation, weather proofing, and performance of your new energy efficient vinyl windows. When you compare the quotes I know you’ll be pleasantly surprised.