Q.  Is there any glass area lost with the new windows?

A.  Because a replacement window is a self contained unit and has it's own master frame to fit into your existing wood frame, most people are unhappy with the amount of glass that they loose with their new window.  Many replacement windows have and extremely heavy extrusion which tends to add a bulk to the window.  Look for a window with a low profile extrusion that will give you strength, but also the most glass area possible.  New technology has made it so that you hardly notice any glass area loss.

Q.  How are the frame and sash profiles assembled?

A.  There are several different ways to assemble windows.  The oldest and one of the most common are screwed assembles.  This means the main frame and sash profiles are screwed together mechanically.  This is not desirable because your window after years of use, opening and closing, can go out of square and rack in the opening preventing the window from operating smoothly and maintaining it's thermal efficiency.  The best quality windows are now fully welded at the master frame and sash profile.  This gives you a strong corner in the sash as well as the master frame, so your window will remain square and operate smoothly for years to come.

Q.  What other features should I look at for thermal efficiency in a replacement window?

A.  A replacement window should have stripping on two sides of the sash.  Wherever the sash meets the main frame is insulated with fine seal type weather stripping.  an interlock at the meeting rail is also very important.  This means that each sash interlocks with the other providing a nice, tight seal against air infiltration at your meeting rail, as well as preventing anyone from being able to jimmy your lock open from the outside.  The locking system should consist of at least 2 cam action type locks on any window over 24 inches.  These locks should pull the sash tight together where the interlock meets at the meeting rail providing even a tighter seal at this area.

Q.  What type of spacing system is used in the insulating glass?

A.  Windows are 90% glass and this is what gives you the most of your thermal efficiency in your window.  There are many glass options and spacing systems that are used in insulating glass.  Most windows are made with an aluminum or some type of metal spacer which conducts cold.  Aluminum and steel transfer heat and cold very readily through glass.  Your better off with material that provides you with a warm edge type spacing system, where the glass is touching material that does not allow the transfer of this heat and cold.  Swiggle strip is one such spacing system.  This is a continuous spacer that is warmedged and provides superior insulated glass and extended life against seal failure.  Low E and argon gas are also options to discuss with your contractor.  These products increase the R value of the glass and reduces fading of drapery and furniture.

Q.  How is window installed?

A.  Take a poor quality window and install it extraordinarily and have it perform well.  You could take an extraordinary window and install it poorly and it will not perform well.  It's very important that the window is secured in the opening, squared properly, insulated and caulked properly, and installed by a trained professional mechanic to insure proper operation and thermal efficiency of the window.  Make sure your window company explains the steps they take when installing your window.  Will they remove rotted wood frame; is there an added cost to job?  Ask questions!!