Our home has old single pane sliding windows with no frames. They don’t retain the house heat well and mildew has built up along the sills. Is there any reasonably inexpensive replacement alternative?

The windows you refer to sound like a once popular “Pierson” slider, made in Canada and installed in thousands of homes the 1950’s and 1960’s. They were stylish in their day because they were sashless. But even with their outer storm window component they were drafty because they did not have stiles to seal their glass panes at the mid-rail.

With the cost of energy continuing it’s climb it is cost effective to replace these windows. There are Federal grants available that you may qualify for that will help you pay for this energy efficiency upgrade. A home “energy audit” completed by a certified energy auditor will help you get started with your project.

 Often your local window and glass companies can replace this type of window without having to cut into your existing siding or interior walls. They will manufacture a modern thermo-pane window that will retrofit into your existing window opening without modifying or damaging interior or exterior wall finishes. This can save you money and time in costly finishing repairs and your payback period in fuel savings with thermopane windows will be significantly reduced because your siding and drywall won’t need re-finishing.