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A knock on is a frame extender which allows you to increase the thickness of the window frame on a specified side. Great for properties with deep plaster, render or tiles over tiles. 15mm, 25mm or 40mm knock on’s are available.

Some fitters buy knock on’s as a precaution, for example where the window opening has not been built yet. 

If your window measures over 35mm bigger on the outside than it does on the inside, you would be advised to select knock on’s so that you do not lose most of the visible frame on the inside.

Knock on’s simply clip or slide on the window profile.

Important: The thickness of any chosen extenders is included in the chosen window width/height.

If you wish to add an extender without automatically decreasing your window's width or height please add a note at checkout.

For more advice please contact us.

To comply with the Building Regulations there must be toughened safety glass in “critical locations” to protect people from injury. The most likely locations for accidents caused by glass breakage, which could result in cutting and piercing injuries are in doors, door side panels, low windows and low level glass in walls and glass partitions. Critical Locations are considered to be:

1. Glazing in doors – Glass which is wholly or partially within 1500mm from floor level. Any glass in doors that does not start over 1500mm from the floor must be safety glass. We will automatically manufacture your doors using toughened safety glass.

2. Glazing adjacent to doors – Windows/side panels wholly or partially within 300mm of the edge of a door and which is also wholly or partially within 1500mm from floor level must be safety glass. This means if your window is attached to a door you will need to order toughened safety glass.

3. Low Level Glazing – Not covered in (1) OR (2) ABOVE – Other glazing that is wholly or partially within 800mm from floor level. This means that windows that are not located within 300mm of a door must use safety glass if the bottom of the glazing is within 800mm of the floor level. This means if your window is below 800mm from the floor you will need to order toughened safety glass.

We can accept no responsibility if you do not order toughened safety glass for your windows. If you are in doubt please call us to enquire.

Our standard C rated window has a minimum u-value of 1.6, whereas our A+2 rated window has a u-value of 1.37. Simply put, our C rated window is sufficient to meet current requirements, but our A+2 rated window will save you more in energy costs.

Most windows require an external cill to drain water away correctly. If you already have a stone or tiled cill as part of the building you may not require a cill. As standard our cills are cut 100mm wider than the window frame, giving you 50mm horns on each side.

85mm stub cill; This cill only protrudes from the external window face by 15mm.

150mm normal cill; Our most common and recommended cill size covers most situations. Protrudes from the external window face by 85mm. 

180mm long cill; If your windows are set further back into the brickwork then you may require our largest cill which protrudes from window by 110mm. If a 150mm cill will have less than 25mm overhang please select 180mm cill.

225mm extra long cill; Usually required if you are having insulation added to the outside of your property, meaning that your windows will be set right back. This cill will protrude by 155mm

Please note:  If a cill is chosen it will be included within the overall height of the window ordered ie; if you order a window 1200mm in height your finished size including the cill will be 1200mm.

For more advice please contact us.

Our Espagnolette multipoint locking mechanisms offer security, and the convenience of a night latch facility which allows you to open the window slightly and lock into position.

Our Shootbolt multipoint locking mechanisms give the added benefit of extra shootbolts at each end of the opening vent, offering even more security.

Building regulations state that a fire-escape window should have an unobstructed openable area that is at least 0.33 sqM and at least 450mm high and 450mm wide. To make this possible your window will need to be fitted with a 90 degree opening fire escape hinge. We advise that you order fire escape hinges for every bedroom window, as well as any other windows you might want to use as a means of fire escape such as the bathroom or landing window. 

All windows for newbuild projects are required to have tricklevents fitted. Please order tricklevents for any windows being used for newbuild projects. For replacement projects we suggest you might want to put tricklevents in your bathroom and kitchen windows for added ventilation. Bedrooms can also benefit from this facility.

Standard doors come with a pvc frame at the bottom. If your door is for disabled access you may want to consider a low threshold. Please check that the internal floor level is not too high if the door opens inwards.

As all of our windows and doors are made to order, if there is something you need that you cannot see on our site please call or email us with your enquiry. The style of windows available is almost limitless but we can advise you on the alternatives if it is not possible. 

By law all windows and doors manufactured in the UK now have to be CE marked for safety and quality assurance. The frames should either carry a CE mark and number, or be supplied with a paper certificate for you to keep in your records. EazyBuy supply a paper CE certificate with all of their windows and doors.