Home > Companies > Selectaglaze Ltd > Series 20 Vertical Sliding

Slimline vertical sliding (VS) secondary glazing unit in two or three pane sliding sash options. Contra-sliding panes provide access to the primary windows for cleaning and maintenance.

Sashes cannot be removed. A minimum frame gap of 75 mm is recommended.

Sashes slide within the frame so do not interfere with blinds or curtains. Twin brush seals ensure high sealing efficiency. All fixings are concealed within the frame, which may be linked to other frames with a colour-matched mullion/ transom section.

Will reduce heat loss by up to 50% using standard glass and up to 65% with a thermally efficient glass (low emissivity).

Suitable for listed buildings where the primary glazing cannot be changed. It is a reversible adaptation, so generally accepted by heritage agencies.

Thermal performance:

U-values as low as 1.8 W/m²K (timber primary window and low-E glass in secondary glazing).


  • Acoustic: Tested in accordance with BS EN ISO 140-3: 1995 for acoustic performance. Between 39 and 46 dB can be achieved.
  • Blast tested to ISO 16933 Classification code EXV 45.

Standard product features


- Material:

Extruded aluminium alloy 6063-T6.



Sash height to width ratio should not normally exceed 1:3. Maximum sash area subject to 20 kg weight capacity.

  • Sash, minimum (h x w): 300 x 350 mm.
  • Sash, maximum (h x w): 1500 x 1400 mm.
  • Curved head or jamb minimum radius: 450 mm.

Thermal performance:

Values of <2.9 W/m²K available; consult manufacturer for details.

NBS Specification

NBS Create logo
This product is associated with the following NBS Create clause:
25-90-35/150 Putty-fronted single glazing system

NBS Specification

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This product is associated with the following NBS clauses:

Product specification

An important note about specifying



Selectaglaze Ltd


+44 (0)1727 837271

Product reference

Series 20 Slimline Vertical Sliding (VS)


[As primary window designs/ sightlines]
[Vertical sliding, two pane]
[Vertical sliding, three pane]


[As drawing]
Insert details.
[As schedule]
Insert details.

Acoustic performance

[ ______ ]

Thermal performance

[ ______ ]

Blast performance

[Not required]
[ISO 16933 EXV 45]


 - Finish:
[Anodizing, Analok bronze AA25]
[Anodizing, Analok silver AA10]
[Polyester powder-coating, HIPCA 9910 semi-gloss white]
[Polyester powder-coating, RAL]
Insert RAL colour.
[Wood grain effect]
 - Gloss level:
[Not required]
[High gloss]


 - Type:
[Laminated, low-E]
[Toughened, low-E]
 - Thickness:
[4 mm]
[6 mm]
[6.4 mm]
[6.8 mm]
 - Gasket:


 - Handles:
[H3 Recessed finger pull, colour matched to frame]
[H17 Cranked D handle, colour matched to frame]
 - Locks:
[Not required]
[L2 fitch catch (lockable), white]
[L2 fitch catch (lockable), black]
[L2 fitch catch (lockable), gold]
[L2 fitch catch (lockable), polished chrome]
[L2 fitch catch (lockable), brushed steel]
[L4 plunge lock, silver]
[L13 S10/20 sliding latch]

Trickle ventilators

[Not required]
[Over the frame standard ventilator]
[Over the frame acoustic ventilator]

Acoustic reveal linings

[Not required]
[Vinyl faced acoustic foam]

Manufacturer details

Alban Park,
Hatfield Road,
St Albans,
Hertfordshire, AL4 0JJ
Tel +44 (0)1727 837271
Fax +44 (0)1727 844053
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