Competitive prices. Excellent Service with prompt delivery. I would recommend IQ to others and will certainly use again.
Mr K
Excellent, professional, efficient service from IQ Builders Merchant. Needed to purchase 3000 bricks to finish a new build project, Oliver was great in sourcing the same bricks, at a very good price, had them delivered in a matter of a few days. Happy to use again and to recommend.
Mr G
Ordered the STUNNING XL Joinery PreFinished Walnut Portici Door . Very pleased with the service 10/10
Mrs W

VELUX WHITE Polyurethane TOP-HUNG Roof Window GPU

VELUX WHITE Polyurethane TOP-HUNG Roof Window GPU
VELUX WHITE Polyurethane TOP-HUNG Roof Window GPU
VELUX WHITE Polyurethane TOP-HUNG Roof Window GPU
VELUX WHITE Polyurethane TOP-HUNG Roof Window GPU
Operated with an elegant handle at the bottom, we recommend this roof window for loft conversions where the window is in easy reach. Get a panoramic view and a feeling of being outside.
Delivery Time: Estimated 3-5 Days
Product Code: GPU CK04 0070
Product Brand: Velux
£450.75 (Exc Vat)
£540.90 (Inc Vat)
- +
  • Description
  • Delivery
  • Price Request

The top-hung window is manufactured in high quality pine with the option of a white painted internal finish (GPL) or white polyurethane internal finish (GPU). It is suitable for installation into roof pitches between 15° and 55°. For installations between 55° and 75° special springs will be required.

Not advised for high level (out of reach) installation. The bottom edge of the window should be placed approx. 0.90 – 1.20m above the floor for ease of operation.

Roof pitch

  • Ventilation bar with dust and insect filter – Allows fresh air to enter the room while the window is securely closed
  • Sash rotates 180° from inside – Allows easy and convenient cleaning
  • Barrel bolt – Allows the window to be locked in to position at 180° for secure cleaning of the exterior pane internally

The sash which is top-hung is opened and closed using the bottom handle and can remain open in any position up to 45 degrees.

Size  Description
(--34) glazing Double glazed, laminated opaque inner pane, 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 & 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. 
(--70) glazing  Double glazed, laminated inner pane, toughened outer pane. 

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.

  • 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

High quality moulded polyurethane protects the timber core and is easy to wipe clean.

Natural pine finish

Warmth of natural pine with long lasting triple coat finish.

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

Also available: titanium zinc, copper or other cladding types and colours.

Best practice installation

Installation products recommended by VELUX
Flashings  Linings
Single installation (ED_)
Twin installation (EB_)
Combi installation (EK_)
Insulation Collar (BDX)
Underfelt Collar (BFX) includes transverse drainage gutter
Vapour Barrier (BBX)

Blinds, Awnings/Shutters
Interior sunscreening  Awning and shutters  Accessories 
Blackout Blind – Manual (DKL)
Roller Blind – Manual (RFL)
Flying Pleated Blind – Manual (FHL)
Venetian Blind – Manual (PAL)
Duo Blackout Blind – Manual (DFD) 
Awning Blind – Manual (MAL)
Roller Shutters – Manual (SHL) 
Insect screen - manual 

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
CK04  GPL, GPU  550 x 978 371 x 783  495 x 919 
CK06  GPL, GPU  550 x 1178  371 x 983  495 x 1119 
FK06  GPL, GPU  660 x 1178  481 x 983  605 x 1119 
FK08  GPL, GPU  660 x 1398  481 x 1183  605 x 1339 
MK04  GPL, GPU  780 x 978  601 x 783  725 x 919 
MK06  GPL, GPU  780 x 1178  601 x 983  725 x 1119 
MK08  GPL, GPU  780 x 1398  601 x 1203  725 x 1339 
MK10  GPL, GPU  780 x 1600  601 x 1405  725 x 1541 
PK04  GPL, GPU  942 x 978  763 x 783  887 x 919 
PK06  GPL, GPU  942 x 1178  763 x 983  887 x 1119 
PK08  GPL, GPU  942 x 1398  763 x 1203  887 x 1319 
PK10  GPL, GPU  942 x 1600  763 x 1405  887 x 1541 
SK06  GPL, GPU  1140 x 1178  961 x 983  1085 x 1119 
SK08  GPL, GPU  1140 x 1398  961 x 1203  1085 x 1339 
SK10  GPL, GPU  1140 x 1600  961 x 1203  1085 x 1119 
UK04  GPL 1340 x 978  1161 x 783  1285 x 919 
UK08  GPL, GPU  1340 x 1398  1161 x 1203  1285 x 1339 

Cross section/
measurements (mm)

Size chart

Technical Data 

Ventilation and daylight area

Size  Ventilation flap – free area [10³mm²]* Ventilation flap – equivalent area [10³mm²]* Ventilation – open window manual [m²]* Effective daylight area [m²]
CK04  2.8 2.6 0.39 0.29
CK06 2.8 2.6 0.48 0.37
FK06  3.7  3.1  0.60 0.47 
FK08  3.7  3.1 0.72 0.58
MK04  4.5 3.7 0.58 0.47
MK06  4.5 3.7 0.72 0.59
MK08  4.5 3.7 0.87 0.72
MK10  4.5 3.7 1.01 0.85
PK04  6.1 4.6 0.72 0.60
PK06  6.1  4.6  0.89 0.75 
PK08  6.1  4.6 1.08 0.91 
PK10  6.1 4.6 1.25 1.07
SK06  7.2 5.6 1.09 0.95
SK08  7.2 5.6 1.32 1.14
SK10  7.2 5.6 1.54 1.35
UK04  10.6  6.6 1.05 0.91
UK08  10.6  6.6  1.54 1.41

*Measured to EN 13141-1

Technical data


 Pane variant --34 --60  GGL --62 GGU --62 
Thermal transmittance, Uw[W/m2K] 1.2 1.2 0.83 0.81
Thermal transmittance Ug[W/m2K] 1.0 1.0 0.5 0.5
Sound insulation, Rw[dB]             35 37 42 42
Air permeability Class 4 Class 4 Class 4 Class 4
Light transmittance, Tv  0.53  0.61 0.65 0.65
Total solar energy transmittance, g  0.50  0.30 0.50 0.50

 Pane variant --66 --70  EN/ISO Standard
Thermal transmittance, Uw[W/m2K] 1.0 1.3 EN ISO 12567-2
Thermal transmittance Ug[W/m2K] 0.7 1.1 EN 673
Sound insulation, Rw[dB]           37           35 EN ISO 10140-2
Air permeability Class 4 Class 4 EN 1026
Light transmittance, Tv  0.69  0.79 EN 410
Total solar energy transmittance, g  0.50  0.64 EN 410

Here at IQ Builders Merchant we offer such a wide variety of products in all manner of shapes, sizes and weights. Each of our ranges has a particular delivery process to ensure the safe delivery of each item. Below we have listed a selection of our best selling ranges and the delivery time for these ranges;

  • Brick Reinforcement - 1-2 Days

  • Building Materials - 1-2 Days

  • Lintels - up to 30 Days

  • Deanta Doors - 3-5 Days

  • XL Joinery Doors - 5 Days

  • LPD Doors - 3-5 Days

  • Timber Windows - 4-5 Weeks

  • Drainage 2-3 Days

  • Velux Roof Windows 3-5 Days (please check before ordering as some are now on longer lead times)

All deliveries are subject to stock and we will be sure to give you as much notice as possible for any stock issues that may affect your delivery.

Any lead times quoted online or by a member of our staff, will be in working days (Mon-Fri).

Additional Delivery charges apply for the following postcodes: PA, DD, PH, KW, KV, AB, IV, HS 

A preferred delivery date can be entered when ordering, however this is not guaranteed. 

Deliveries are made between 7.00am – 5.30pm Monday - Friday although we will give you as much notice as possible for early/late deliveries.

Delivery will only be arranged to destinations within mainland UK. Please supply the full delivery address at the time of order this may differ from the billing address so long as the billing address matches the card holder’s address.

Delivery will occur when the Goods are ready for unloading at the delivery address specified at time of order or as subsequently agreed by both the buyer and IQ Builders Merchant.

Any dates specified by IQ Builders Merchant for delivery of the Goods are intended to be an estimate and time for delivery shall not be made of the essence by notice. If no dates are so specified, delivery shall be within a reasonable time.

Subject to the other provisions of these conditions, IQ Builders Merchant shall not be liable for any direct, indirect or consequential loss (all three of which terms include, without limitation, pure economic loss, loss of profits, loss of business, depletion of goodwill and similar loss), costs, damages, charges or expenses caused directly or indirectly by any delay in the delivery of the Goods.

IQ Builders Merchant shall arrange for delivery to site on the understanding that there is a suitable road to the delivery address requested. If no such road exists delivery will be made to the nearest point to which, in the opinion of the driver, the vehicle may safely proceed and unload. Except for the use of a vehicle mounted crane, the Buyer will provide all necessary labour and equipment required to unload the Goods promptly.

A signature on the delivery note constitutes that all materials have been received in good order.  It is the responsibility of the buyer to ensure that all goods have been checked and any damages noted to the delivery driver at the time of delivery.

Delivery of all Heavyside/Big & Bulky/Pallet items are made kerbside.

All deliveries of palletised products (Brick/Block/Paving/Specified at time of order) will be delivered using a pallet truck and if this is over 1T mechanical offload will be required on site. A Crane offload delivery service is available also at an extra cost.

Parcel deliveries will only be made once to the specified delivery address, any required re-delivery may be chargeable.

It is the responsibility of the buyer to be home/on site on the day of delivery agreed by both the buyer and IQ Builders Merchant.


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