Introduction
The centre-pivot window is a classic and versatile design manufactured in high quality natural pine with the option of white-painted or clear lacquered pine internal finish (GGL) or a white polyurethane internal finish (GGU). It is suitable for installation into roof pitches between 15° and 90°. For easy operation it is recommended to place the top frame of the window 1.85-2.20m above the floor.

VELUX recommend that all roof windows including solar or electrically operated roof windows are installed with a laminated pane for instances above 2.20m.
Roof pitch
15o - 90o
Features
  • Ventilation bar with dust and insect filter – Allows fresh air to enter the room while the window is securely closed
  • Friction springs – Allows easy operation of window
  • Sash rotates 180° from inside – Allows easy and convenient cleaning
  • Barrel bolt – Allows the window to be locked in two positions: 
- At 180° for secure cleaning of the exterior pane internally 
- At 5° to allow extra ventilation
Operation
The window is operated manually. The upper section which is top-hung is opened and closed using the bottom handle and can remain open in any position up to 45o. The lower section which is bottom-hung is opened and closed using the handles on the top sash. 
Glazing
Glazing unit Description
(--34) glazing
Only available for roof window type GGU 
 Double glazed, laminated opaque inner pane, toughened outer pane. 
(--50) glazing
 Double glazed, toughened outer pane. 
(--60) glazing
 Double glazed, laminated inner pane, toughened outer pane with easy-to-clean coating, enhanced noise reduction. 
(--62) glazing  Triple glazed, laminated inner pane, toughened outer pane with easy-to-clean and anti-dew coating. Provides enhanced U-value and noise reduction. 
(--66) glazing  Triple glazed, laminated inner, toughened outer pane with easy-to-clean, anti-dew coating and enhanced noise reduction. 
(--68) glazing  Triple glazed, laminated inner, toughened outer pane with anti-dew coating.
(--70) glazing  Double glazed, laminated inner pane, toughened outer pane. 
(--70Q) glazing  Double glazed, laminated inner pane, toughened outer pane. Provides a burglary resistance of Class P4A.
Maintenance
The pane should be cleaned with a soft, clean, lint-free cloth or non-abrasive sponge. The rest of the window can be cleaned with ordinary household cleaners. The filter can be removed and either washed or replaced.
Guarantee
  • 10 year VELUX guarantee on windows and flashing kits.
  • 3 year guarantee on blinds, shutters, awnings and electrics.
Interior finish
White-painted finish

High-quality pine wood with water-based long-lasting white paint with discrete wood grain. Perfect for almost all rooms.

White maintenance-free finish

Strong core of thermo-modified wood with a seamless waterresistant polyurethene coating. Perfect for high-moisture rooms and out-of-reach solutions.

Natural pine finish

High-quality pine wood with matte water-based transparent lacquer and visible wood grain. Fits wooden ceilings and wall.

Cladding
NCS standard colour (Grey): S 7500-N nearest RAL standard colour: 7043.

Also available: titanium zinc, copper or coloured aluminium.

Best practice installation
Installation products recommended by VELUX
Flashings 
 Installation products
 Linings
Single installation (ED_)
Twin installation (EB_)
Combi installation (EK_)
 Insulation Collar (BDX)
Underfelt Collar (BFX) includes transverse drainage gutter
Vapour Barrier (BBX)
 Linings up to 30 cm roof thickness (LSB)
Linings up to 40 cm roof thickness (LSC)
Linings up to 50 cm roof thickness (LSD)
Blinds, Awnings/Shutters
Interior sunscreening  Awning and shutters  Accessories 
Blackout blind - Manual (DKL)
Roller blind - Manual (RFL)
Roller blind - Manual (RHL)
Roman blind - Manual (FHB)
Blackout energy blind - Manual (FHC)
Flying pleated blind - Manual (FHL)
Venetian blind - Manual (PAL)
Duo blackout blind - Manual (DFD)		 Awning blind - Manual (MHL)
Roller shutter - Manual (SHL)		 Insect screen - Manual (ZIL)
Technical Data

Please note, not all glazing variants are available in all sizes.

Size  Window Options Exterior Frame
W x H		 Visible Glass
e x f		 Lining Rebate
k x l
BK04  GGL  472 x 978
 293 x 783  417 x 639 
CK01  GGL  550 x 698  371 x 503  495 x 639 
CK02  GGL, GGU  550 x 778  371 x 583  495 x 719 
CK04  GGL, GGU  550 x 978
 371 x 783  495 x 919 
CK06  GGL, GGU  550 x 1178  371 x 983  495 x 1119 
FK04  GGL, GGU  660 x 978  481 x 783  495 x 919 
FK06  GGL, GGU  660 x 1178  481 x 983  605 x 1119 
FK08  GGL, GGU  660 x 1398  481 x 1183  605 x 1339 
MK27  GGL  780 x 624  601 x 429  725 x 565 
MK04  GGL, GGU  780 x 978  601 x 783  725 x 565 
MK06  GGL, GGU  780 x 1178  601 x 983  725 x 1119 
MK08  GGL, GGU  780 x 1398  601 x 1203  725 x 1339 
MK10  GGL, GGU  780 x 1600  601 x 1405  725 x 1541 
MK12  GGL  780 x 1800  601 x 1605  725 x 1741 
PK25  GGL, GGU  942 x 550  763 x 355  887 x 491 
PK04  GGL 942 x 978  763 x 783  887 x 919 
PK06  GGL, GGU  942 x 1178  763 x 983  887 x 1119 
PK08  GGL, GGU  942 x 1398  763 x 1203  887 x 1319 
PK10  GGL, GGU  942 x 1600  763 x 1405  887 x 1541 
SK01  GGL  1140 x 698  961 x 503  1085 x 639 
SK06  GGL, GGU  1140 x 1178  961 x 983  1085 x 1119 
SK08  GGL, GGU  1140 x 1398  961 x 1203  1085 x 1339 
SK10  GGL  1140 x 1600  961 x 1203  1085 x 1119 
UK04  GGL, GGU  1340 x 978  1161 x 783  1285 x 919 
UK08  GGL, GGU  1340 x 1398  1161 x 1203  1285 x 1339 
UK10  GGL  1340 x 1600  1161 x 1405  1285 x 1541 
Cross section/
measurements (mm)
Size chart
Technical Data 

Ventilation and daylight area

Size  Ventilation flap – free area [10^3mm²]*
 Ventilation flap – equivalent area [10^3mm²]*
2 layer/3 layer pane 		Ventilation – open window manual [m²]*
 Effective daylight area [m²]
BK04  1.9 2.2/1.8 0.28 0.23
CK01  2.8 2.6/2.0 0.23 0.19
CK02  2.8 2.6/2.0 0.26 0.22
CK04  2.8 2.6/2.0 0.34 0.29
CK06 2.8 2.6/2.0 0.43 0.37
FK04 3.7  3.1/2.2 0.43  0.58 
FK06  3.7  3.1/2.2 0.54  0.47 
FK08  3.7 3.1/2.2 0.66 0.58
MK27  4.5 3.7/2.5 0.30 0.26
MK04  4.5 3.7/2.5 0.53 0.47
MK06  4.5 3.7/2.5 0.66 0.59
MK08  4.5 3.7/2.5 0.81 0.72
MK10  4.5 3.7/2.5 0.94 0.85
MK12  4.5 3.7/2.5  1.07 0.97
PK04  6.1 4.6/2.9 0.66 0.60
PK06  6.1  4.6/2.9 0.83  0.75 
PK08  6.1  4.6/2.9 1.01  0.91 
PK10  6.1 4.6/2.9 1.17 1.07
PK25  6.1  4.6/2.9 0.31  0.27 
SK01  7.2  5.6/3.5 0.54 0.48
SK06  7.2 5.6/3.5 1.03 0.95
SK08  7.2 5.6/3.5 1.25 1.14
SK10  7.2 5.6/3.5 1.46 1.35
UK04  10.6  6.6/4.1 0.98 0.91
UK08  10.6  6.6/4.1 1.54 1.41
UK10  10.6 6.6/4.1 1.80 1.63

*Measured to EN 13141-1

Technical data

Glazing

 Pane variant --34 --50 --60  GGL --62 GGU --62 
Thermal transmittance, Uw [W/m2K]
 1.3 1.3 1.3 0.83 0.81
Thermal transmittance, Ug [W/m2K]
 1.0 1.0 1.0 0.5 0.5
Sound insulation, Rw [dB]
 35 32 37 42 42
Air permeability
 Class 4 Class 4 Class 4 Class 4 Class 4
Light transmittance, Tv  0.51  0.69 0.62 0.70 0.70
Total solar energy transmittance, g  0.46  0.46 0.30 0.52 0.52

 Pane variant --66 --68 --70 --70Q  EN/ISO Standard
Thermal transmittance, Uw [W/m2K]
 1.0 1.1 1.3 1.3 EN ISO 12567-2
Thermal transmittance, Ug [W/m2K]
 0.5 0.5 1.0 1.1 EN 673
Sound insulation, Rw [dB]
 37 35 35 35 EN ISO 10140-2
Air permeability
 Class 4 Class 4 Class 4 Class 4 EN 1026
Light transmittance, Tv  0.71 0.72 0.68 0.80 EN 410
Total solar energy transmittance, g  0.51 0.52 0.46 0.62 EN 410