Sash Window Specialist
A sash window specialist restores, repairs, and replaces traditional sliding sash windows. They combine heritage joinery skills with modern techniques to preserve the character of period properties while improving thermal and acoustic performance.
What does a sash window specialist do?
Sash window specialists preserve and improve traditional windows, including:
- Full sash window restoration (re-cording, re-glazing, timber repair)
- Draught-proofing with concealed brush or compression seals
- Slim-profile double glazing retrofitting into existing frames
- Timber decay repair using splice repairs and epoxy consolidation
- Replacement sash windows in traditional styles
- Secondary glazing installation
- Listed building window work to conservation standards
- Hardware restoration and replacement (locks, lifts, pulleys)
Do sash window specialists need qualifications?
Sash window restoration is not a specifically regulated trade, but it requires specialist joinery skills and heritage building knowledge. For listed buildings, the work must satisfy conservation officers and may need Listed Building Consent.
Experienced specialists understand the balance between preserving original fabric and improving performance. Membership of conservation bodies or heritage craft organisations indicates specialist knowledge. Some specialists are accredited by Historic England's register of conservation practitioners.
What to look for when hiring a sash window specialist
When choosing a sash window specialist, consider:
- Conservation experience — If your property is listed or in a conservation area, ensure the specialist has experience with planning and consent requirements.
- Restore vs replace approach — A good specialist will always assess restoration first. Original windows often have better timber than modern replacements.
- Draught-proofing system — Ask about the draught-proofing method. Concealed systems are unobtrusive and can reduce draughts by up to 80%.
- Slim-profile double glazing — Modern slim units (11–14mm) can fit existing sash frames, providing double glazing without changing the appearance.
- Portfolio of period properties — Ask to see examples of completed work on properties of a similar age and style to yours.
Frequently Asked Questions
How much does sash window restoration cost?
Sash window restoration costs £500–£2,000 per window depending on condition and scope. Draught-proofing alone costs £200–£400 per window. Slim-profile double glazing in existing frames costs £400–£800 per window. Replacement timber sash windows (new build to match) cost £2,500–£4,000+ per window.
Should I restore or replace my sash windows?
Restoration is usually preferable where possible. Original sash windows are often made from slow-grown timber that outlasts modern softwood. Restoration with draught-proofing and slim double glazing can achieve performance close to new windows at lower cost, while preserving character and property value. Replacement is appropriate where timber decay is too extensive to repair economically.