Firth Park · S5
Sash window glazing in Firth Park, Sheffield
Around Firth Park clock tower, Firth Park still carries a lot of original glazing — bay sashes and steel casements. Where those are georgian, victorian and edwardian, roughly 1750–1910 the failure mode is predictable: the sash box is hollow and the counterweight pockets leak air, so the loss is around the window as much as through it. Firth Park is not a conservation area, so the decision is purely technical rather than a consent question. Most enquiries here come from owner-occupiers doing one or two rooms at a time, so we price per opening rather than per house. Firth Park is about 3 miles from central Sheffield, so a survey here is a short run for our team off the M1 J33.
Local conditions we design around
A sash box is a ventilated void by design; most of the perceived draught comes through the pulley stiles rather than through the glass.
We avoid any fixing into the pulley stile or staff bead, so the install is fully reversible for a future owner or a conservation officer.
Firth Park stock is Edwardian terraces and 1930s council semis and the prevailing glazing is bay sashes and steel casements, which is why sash window glazing comes up here so often.
We measure the reveal at three heights because sash openings are rarely square after a century of settlement.
Firth Park carries no conservation designation, so the specification is decided on performance alone.
What happens next
- Step 1
Send a photo of the window — with two vertically sliding sashes running in a boxed frame we can usually tell you the likely system before we visit.
- Step 2
Survey in Firth Park: we measure the reveal at three heights because sash openings are rarely square after a century of settlement.
- Step 3
Manufacture to the templated sizes with your chosen finish.
- Step 4
Room-side install with no external access and no alteration to the original frame.
What goes in, and why
| Window type | two vertically sliding sashes running in a boxed frame, usually with a horn detail on the upper sash (Georgian, Victorian and Edwardian, roughly 1750–1910) |
|---|---|
| Underlying problem | the sash box is hollow and the counterweight pockets leak air, so the loss is around the window as much as through it |
| System we fit | vertical sliding secondary units that mirror the original movement |
| Glass specification | 4 mm Low-E for thermal-led jobs, 6.4 mm laminated where noise is the driver |
| Measurement | we measure the reveal at three heights because sash openings are rarely square after a century of settlement |
| Heritage position | nothing is fixed into the sash box itself — the frame is fixed to the reveal lining, so historic joinery is untouched and the work is reversible |
Local reference points
- Area
- Firth Park (S5)
- Town
- Sheffield, South Yorkshire
- Housing era
- Edwardian terraces and 1930s council semis
- Typical windows
- bay sashes and steel casements
- Landmark
- Firth Park clock tower
- Conservation area
- No
- Window style
- Sash Windows
- Period
- Georgian, Victorian and Edwardian, roughly 1750–1910
Quotes are written, itemised per opening, and hold for 60 days.
Every opening is templated on site — we do not price secondary glazing by the square metre.
Measured performance figures come from our own post-install testing, not manufacturer maximums.
Cavity depth does more for acoustic performance than glass thickness, and we design for it first.
Recent installs nearby
Nether Edge Grade II sash retrofit
Six original box sashes fitted with balanced vertical secondary sliders — full listed-building consent secured in six weeks.
Ecclesall Road bay-window sound retrofit
Three-panel horizontal sliders across a 3.2 m Edwardian bay — Rw measured at 47 dB post-install.
Kelham Island loft conversion
Four large steel-frame factory openings sealed with slim satin-anodised horizontal sliders. Post-install U-value 1.87 W/m²K.
Send us the opening sizes
A photo and rough dimensions are enough for a written quote inside one working day. Send a photo of the sash window glazing — with two vertically sliding sashes running in a boxed frame in a edwardian terraces and 1930s council semis Firth Park property we can usually spec it before we visit.
Common questions
Will secondary glazing stop my sash windows rattling?
Yes, and it does it without touching the sash. The rattle is wind pressure moving a loose sash in its box, and a sealed room-side pane removes the pressure differential driving it.
Can I still open the sash behind it?
Yes. Vertical sliding secondary units move on the same axis, so both sashes stay operable.
Does it damage original joinery?
No. The fixing is into the reveal lining, not the sash box, and the whole system can be removed later without trace.
Can we do one room now and the rest later?
Yes. We template and price per opening, so a later phase is quoted at the same rate — there is no penalty for splitting the work.
Will it get in the way of curtains or blinds?
Rarely. Reveal-fixed units sit inside the existing recess; where the recess is shallow we face-fix and reposition the blind, which we flag at survey rather than on the day.
Sash window glazing in Firth Park — the short version
The sash box is hollow and the counterweight pockets leak air, so the loss is around the window as much as through it. We fit vertical sliding secondary units that mirror the original movement with 4 mm Low-E for thermal-led jobs, 6.4 mm laminated where noise is the driver, templated to your opening. The draught through the weight pockets is sealed and the original sash keeps operating normally.