Sash Window Repair
in Belgravia SW1
Serving Belgravia, Chelsea, Knightsbridge, Pimlico and surrounding areas — free survey, no call-out fee, 5-year guarantee.
✓ No Call-Out Fee
✓ 5-Year Guarantee
✓ Same-Day Response
✓ Fully Insured
Belgravia’s stucco-fronted terraces and garden squares represent some of the finest period architecture in London. These are grand, meticulously maintained properties where the sash window is not just a functional element but a defining architectural feature.
Hartwell Sash brings the precision and care that these properties demand. We work quietly, cleanly, and to the highest standard — restoring windows that are worthy of the buildings they belong to.
What we do — done properly
Every service is carried out with care and precision. We work on grand period properties and Listed Buildings — and we understand what these windows need.
🌬️ Draught Proofing
Cold air and noise eliminated permanently — without changing the appearance of your windows. We replace staff bead and parting bead with precision brush pile seals and fit a brush seal at the meeting rail.
- Full inspection of frame, sashes and existing beads
- Both sashes carefully removed from the frame
- Staff bead replaced with brush pile bead — both sides
- Parting bead replaced with brush pile bead — both sides
- Brush seal fitted to meeting rail — eliminates central gap
- Sashes re-hung, balanced and tested
🔧 Sash Cord Replacement
Windows that slam shut or won’t stay open — fixed properly. We replace all four cords and rebalance both sashes as standard.
- Staff beads carefully removed to access the sash
- Both upper and lower sashes removed and inspected
- Weight box opened — cast iron weights cleaned and checked
- All four cords replaced with quality waxed sash cord
- Pulley wheels oiled and tested for smooth running
- Sashes re-hung, balanced and tested
🪟 Glass Replacement
Cracked, broken or misted panes replaced carefully — preserving the original timber frame. Heritage glass available for Conservation Areas.
- Free survey to assess glass type and frame condition
- Glass sourced to match original specification
- Sash removed, old glass carefully taken out
- New glass fitted, sealed and putty finished
- Sash re-hung and tested — area left clean
🪵 Timber Repair & Repainting
Rotting timber repaired, not replaced wherever possible. Professionally repainted to protect your windows for years to come.
- Full inspection to assess extent of damage
- Damaged timber cut back to sound wood
- Epoxy filler or replacement timber used to rebuild
- Sections shaped and sanded to match original
- Windows primed, undercoated and finished professionally
- Ironmongery cleaned, adjusted or replaced
🏠 Sash Replacement — When Repair Is Not Enough
We always try to repair before we replace. But when a window is genuinely beyond saving, we supply and fit heritage timber sash windows made to match the original design of your property. Not uPVC — timber, made properly.
- Free survey to confirm whether repair or replacement is the right decision
- Where the box frame is sound, we replace only the sash units — preserving shutters, architraves and original plasterwork
- New sashes manufactured to measure in timber with slim sightlines
- Ironmongery and pulley wheels replaced as standard
- Glazed with single glass, slimline double glazing or heritage glass as required
- Fitted, balanced, sealed and painted — property left clean and tidy
Why Belgravia homeowners choose Hartwell Sash
Restore First
We never recommend replacement when repair will do the job. Your original windows are always our priority.
Period Specialists
Victorian, Georgian, Edwardian — we understand Conservation Areas and Listed Buildings across London.
5-Year Guarantee
Every job is covered by a 5-year workmanship guarantee. Fully insured and fully accountable.
Free survey in Belgravia
We visit your property, assess every window and give you an honest quote — no call-out fee, no obligation, no pressure. Same-day response guaranteed.