Is it better to repair or replace old sash windows?

At Sash Window Experts, we can carry out a full repair, refurbishment or replacement services for your timber sash windows, as required. In many cases, simply repairing the defect may suffice. This option is certainly cheaper in the short term; however, it may not be the best long-term solution. Our expert surveyors will be able to advise the best course of action, having carried out a site survey. We will always recommend the best product/service for your needs.

Do I need planning permission to have my sash windows replaced?

The answer to this question depends on the type and location of your property. If your home is situated in a Conservation Area or the building is listed, you will need planning permission (and Listed Building Consent) before making any significant alterations. If there are no planning restrictions, you may be able to proceed straight away. Always check with your local planning authority if you’re not sure. If consent is required, Sash Window Experts can help with the necessary paperwork and guide you through the process.

Will it be necessary to erect scaffolding for the works?

This depends on the location of the affected windows and the exact nature of the work to be completed. Once we have carried out our site visit, we will be able to tell you if scaffolding will be required. In most cases, we can carry out sash window repairs from inside the home. Should scaffolding be needed, we can arrange for an external contractor to put it up at very reasonable rates.

How do I know if my sash windows are beyond repair?

A professional survey is the best way to assess this. Localised timber decay, worn cords, rattling, and sticking sashes are often repairable. Complete structural failure, missing joinery, or severe long-term deterioration may make replacement the better solution.

Can rotten timber sash windows be restored?

Yes, often they can. Decayed areas can frequently be cut out and replaced with new timber sections that match the original profile. The key question is how much sound original material remains.

Can you replace uPVC windows with timber sash windows?

Yes. If original sash windows have previously been removed and replaced with uPVC, we can supply and install traditional-style timber sash windows to reinstate the period appearance.

Will sash window restoration reduce draughts?

Yes. Draught proofing, better fit, renewed components, and careful refurbishment can significantly improve comfort and reduce rattles and air leakage.

Sash Window Replacement and Restoration

Restore original timber sash windows wherever possible. Replace only when repair is no longer the right long-term solution. We’ve brought back to life hundreds of windows that many thought were irreparable.

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At Sash Window Experts, we help owners of period properties decide whether their original sash windows should be repaired, fully restored, or replaced. In most cases, original timber sash windows can be renovated successfully, even when they are draughty, rotten, damaged, or difficult to open. Where restoration is no longer practical, we manufacture and install bespoke replacement sash windows that preserve the character of the property.

For more than 30 years, we have carried out sash window restoration and replacement across Sussex, Surrey and Kent, with a strong focus on period homes, listed buildings, and properties in conservation areas. All our handmade bespoke replacement sash windows are made in our joinery workshop by highly skilled craftsmen who are passionate about giving your period windows the attention to detail they deserve.

Book a free survey to find out whether your windows can be saved, upgraded, or replaced.

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Sash Window Restoration or Replacement: What Is the Difference?

Sash window restoration

Sash window restoration means retaining as much of the original window as possible while repairing defects, improving performance, and preserving the character of the property.

This may include:

Timber repairs to decayed sections
New sills, pulley stiles, beads, cords, and parting beads
Sash easing and rebalancing
Draught proofing
Repairs to damaged mouldings
Upgrades such as double-glazed replacement sashes where appropriate
New locks and catches

Best for: original sash windows that are structurally repairable but no longer perform well.

Sash window replacement

Sash window replacement is used when the original window is beyond reasonable repair, or where modern replacements such as uPVC have already removed the period character and the client wants it reinstated.

Replacement may involve:

Installing new double-glazed timber sashes into an existing original box frame
Replacing previously removed sashes
Supplying and fitting complete new box-frame sash windows
Matching traditional mouldings, horns, weights, and pulley details

Best for: windows with severe deterioration, missing original joinery, or unsuitable modern replacements.

Why We Usually Recommend Restoration First

Replacing original sash windows should usually be a last resort.

Well-restored timber sash windows can:

Last for decades with the right maintenance
Preserve the original appearance of a period home
Avoid the visual compromise of modern plastic replacements
Meet many practical performance goals, including smoother operation and reduced draughts
Help protect the value and architectural character of the property

Modern uPVC may appear attractive at first because of low maintenance and thermal performance, but it cannot replicate the material quality, detailing, or repairability of original timber sash windows. In many period properties, especially in conservation areas, it is also an inappropriate visual substitute.

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Large sash window before and after renovation

Sash window repair before and after photos

Our Sash Window Restoration Service

Our restoration process is designed to preserve original sash windows while improving their function, appearance, and lifespan.

We can:

Repair decayed timber by piecing in new sections to match the original mouldings
Replace sills, pulley stiles, and outer linings where required
Renew cords, beads, and other worn components
Carry out expert draught proofing
Ease and rebalance sticking or poorly operating sashes
Install locks and traditional centre catches
Upgrade suitable windows with double-glazed sash units
Complete comprehensive renovation of original timber sash windows

Restoration vs Replacement: Which Option Is Right for You?

Option	Best when	Main benefit
Repair	A specific defect needs attention	Lowest level of intervention
Full restoration	Original windows are repairable but performing poorly	Preserves original fabric and character
Replacement sashes in existing box frame	Sashes are unsalvageable but box frame remains viable	Improves performance while retaining part of the original window
Complete new box-frame sash window	Original frame and sashes are missing or beyond repair	Full reinstatement of traditional timber sash windows

In simple terms:

Choose repair or restoration when the original window can still be saved.
Choose replacement when repair would not be structurally sound, visually satisfactory, or cost-effective over the long term.

Our Sash Window Process

1. Initial survey

We inspect the condition of each sash window and identify decay, movement issues, draught problems, glazing limitations, and previous alterations.

2. Honest recommendation

We explain whether each window is best suited to repair, full restoration, replacement sashes, or complete replacement.

3. Clear quotation

You receive a quotation based on the work required, with practical guidance on any planning or conservation considerations.

4. Joinery and preparation

Where new timber elements are needed, these are made in our workshop to match the original detailing as closely as possible.

5. Installation and on-site works

Our craftsmen carry out the agreed restoration or replacement works carefully and with respect for the property.

6. Finishing and performance checks

We check operation, fit, and finish, and make sure the windows are working properly before sign-off.

Our Replacement Sash Window Service

Where repair is no longer viable, we manufacture and install bespoke timber replacement sash windows from our joinery workshop.

We can provide:

New double-glazed hardwood or softwood sash units
Traditional moulding and horn details to match the original design
Replacement sashes fitted into existing period box frames
Complete new box-frame sash windows where the originals have been removed
Single- or double-glazed options depending on the property and specification

★★★★★

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Arrange a No Obligation Survey With Mark

Hi, I’m Mark, owner of Sash Window Experts. I’d love to talk to you about restoring period windows. Please fill out the form or call me on 01403 602701 to arrange your FREE no obligation window survey and to discuss your requirements.

Why Choose Sash Window Experts?

Repairs Specialist

Restoring period windows is at the heart of what we do. With over 30 years of experience, our highly skilled craftsmen have repaired and revived hundreds of sash windows that many would have considered beyond repair. Every project is approached with the care, precision and attention to detail that historic timber windows deserve.

Free Window Survey

Call us today for a free window survey and quotation. Let us assess the extent of the damage and repair requirements, with consideration of your budget. You may be pleasantly surprised to find that sash window repair, rather than replacement, is the best option for your property.

Box Sash Window Experts

Box sash windows are a traditional feature of period homes which add charm and character. We have over 30 years experience in working with, repairing and installing box sash windows.

Our Latest Projects

Sash Window Refurbishment and Bay Window Restoration - Exterior build

Restoration or Replacement FAQs

Is it better to repair or replace old sash windows?: At Sash Window Experts, we can carry out a full repair, refurbishment or replacement services for your timber sash windows, as required. In many cases, simply repairing the defect may suffice. This option is certainly cheaper in the short term; however, it may not be the best long-term solution. Our expert surveyors will be able to advise the best course of action, having carried out a site survey. We will always recommend the best product/service for your needs.
Do I need planning permission to have my sash windows replaced?: The answer to this question depends on the type and location of your property. If your home is situated in a Conservation Area or the building is listed, you will need planning permission (and Listed Building Consent) before making any significant alterations. If there are no planning restrictions, you may be able to proceed straight away. Always check with your local planning authority if you’re not sure. If consent is required, Sash Window Experts can help with the necessary paperwork and guide you through the process.
Will it be necessary to erect scaffolding for the works?: This depends on the location of the affected windows and the exact nature of the work to be completed. Once we have carried out our site visit, we will be able to tell you if scaffolding will be required. In most cases, we can carry out sash window repairs from inside the home. Should scaffolding be needed, we can arrange for an external contractor to put it up at very reasonable rates.
How do I know if my sash windows are beyond repair?: A professional survey is the best way to assess this. Localised timber decay, worn cords, rattling, and sticking sashes are often repairable. Complete structural failure, missing joinery, or severe long-term deterioration may make replacement the better solution.
Can rotten timber sash windows be restored?: Yes, often they can. Decayed areas can frequently be cut out and replaced with new timber sections that match the original profile. The key question is how much sound original material remains.
Can you replace uPVC windows with timber sash windows?: Yes. If original sash windows have previously been removed and replaced with uPVC, we can supply and install traditional-style timber sash windows to reinstate the period appearance.
Will sash window restoration reduce draughts?: Yes. Draught proofing, better fit, renewed components, and careful refurbishment can significantly improve comfort and reduce rattles and air leakage.