Historic Window Repair and Rehabilitation

"[T]he repair…of existing windows is more practical than most people realize, …because [they] a lack…awareness of techniques for evaluation, repair, and weatherization."
   Secretary of the Interior National Park Service Preservation Briefs 9 and 13
"I've…assessed the condition of more than a thousand [sashes], and never seen a sash that could not be repaired."
  John Leeke (contractor), Historic Home Works
Any window that can be repaired should be repaired.
  Secretary of the Interior Standards for Rehabilitation Guidelines for Windows

What to Do?

Are Your Windows Steel?

For repair and weatherization of historic steel windows, see the article on Historic Steel Windows Repair, Restoration, and Weatherization.

There is not a single and simple answer, because the repair depends...

Repair goals can range from minimal to extensive. In fact, the less, the better!

Have a plan

The How to Do It section shows what things can be done, from minimal to restoration. Know what the goal is, then plan just the repair needed to get there. Don't overdo it.


Here are ten reasons to restore or repair wooden windows, from the city of Boston.

How to Do It?

Historic windows are simple devices that are constructed of separate simple pieces.

Many repairs of historic windows need only

Basic repairs are as simple for the Do-It-Yourself (DIY) owner and as for a contractor.

Work together with contractors! Save money!

The two courses of action, both covered in detail below

DIY Window Repair and Restoration

The main thing is knowing what to do and how.

Repairs to windows usually are not complicated.. A DIY owner can save money doing some or all of the repairs. For wood windows, many repairs require only simple skills and common tools. Working with metal windows may be more complicated, but with knowledge about them, the DIY owner can learn to do many repairs.

What do you need to know?

You need to know how to do what you need. What you need depends on the goal, the objectives, and the plan.

This web site can help with setting goals and making plans. While the site is thorough on how to repair extensive window damage, it also discusses how to decide how much repair is required

Do It Yourself

The following DIY information is divided into three sections:


Complete Reference Guidebooks for Window Repair and Weatherization.

The guidebooks have information on all aspects of repairing, rehabilitating, restoring, and weatherizing windows. If only a specific repair is needed, then consult the relevant section.

Demonstrations of Complete Window Rehabilitation

The materials here demonstrate the steps in the rehabilitation process presented in the guidebooks. If only specific repairs are required, only the relevant sections of the presentations can be used. Also, consult the materials and demonstrations for specific repairs below

The Michigan Historic Preservation Network and the City of Kalamazoo produced these five videos to demonstrate the process of window rehabilitation. For specific repairs, rather than a full rehabilitation, view just the relevant video. However, knowing all of the steps in window rehabilitation may be helpful even for making limited repairs. More information on each individual step is in the sections below.

Demonstrations of Specific Window Repairs

Most historic wood windows are either the traditional double-hung windows or casement windows. The latter are much simpler.

Specific Problems

Each of these problems is covered in more detail in the collapsable boxes below.

Unsticking Windows


Replacing Window Sash Ropes




Replacing Glass


Sills and Casing


Window Sash


Epoxy Repairs


Stripping Paint and Finish


Repainting Windows


Who Can Help? Hiring Contractors

There are reliable contractors who specialize in the window repair and restoration. They know how to do it correctly.

Since many of the tasks are simple, general contractors, handymen, or house painters may be able to do them. However, employing non-specialized contractors for window repair can be risky.

Replacement window companies will advise you that your windows cannot be repaired and are energy inefficient. Their advice: what you need to do is to buy their new windows! Maybe not.

There are two reasons.

Advice: You need to know what work you need and how it should be done!

Here's how: study the DIY information. Even if you cannot DIY, that is the information that you need to understand what work you need contractors to do, and how they should do it.

Having a plan is very important here again. With a plan that prioritizes the work to be done, an owner can work with a contractor and get the most important work done first and within the budget. Also, if work must be spread out over time for financial reasons, the plan will help the owner and contractor set up the work in a series of affordable stages.


More about Parting Stops