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Loft Conversions

Velux or dormer?

What's the difference between a velux and dormer? Is one better than the other?

10 Answers from MyBuilder Loft Conversion Specialists

Best Answer

Velux and rooflight conversions are the same , velux are a leading manufacturer of roof windows , This type of conversion is generally very cost effective and does not normally need planning permission
A dormer is a extension to the existing roof, allowing for additional floor space and head room within the loft conversion . Dormers protrude from the roof slope normally at the rear of the property and can be built in many styles.


Answered 23rd Feb 2011

I'll keep this frank as loft conversions,velux and dormer's are like a middle name to me, so to speak. So without too much jargon I'll keep it easy.

1. Velux brand is the name given to the company that makes a flat fitting type window which open either by sliding and/or angled openers. You may see them on some roof's. These are added for light without the need for creating additional roof alterations to add head space, for example a loft conversion; loft space above the house is converted to living space. For light one could use velux type windows. This additional space does add value to your property.

2. With a dormer you do away with the need for velux type windows entirely and can add more open space and headroom with plenty of natural light. The roof and the floor are supported/opened up or even raised to become more like a terraced type attic in appearance. These are a little more costly then a velux type conversion but are well worth it as they add more to the property value then just a velux type conversion.

3. UK Management Builders can convert a loft to a dormer or velux style. Most competent builders would be able to do the same. However UKM Builders also advises you speak to an architect about design/space/property value and pop into the Local Authority planning office and just ask them if you need permission as they will advise you of fees and cost/regulations etc.

Hope the above helps.

Kind regards

UK Management Builders LTD


Answered 19th Feb 2011

A Velux window goes flat on to the roof,where a dormer window is built out.The diffrence would be cost.


Answered 17th Feb 2011

A dormer requires altering the structure of the roof timbers and forming a smaller pitched roof which is tiled or slated or a flat roof which is covered in ashfelt, a velux window usually fits in between the rafters flat to the roof requiring little alteration. As with the other answers a dormer gives you more ceiling space but does cost a lot more.


Answered 17th Feb 2011

If you opt for the Dormer option you will need to go through a full Planning application. Velux windows can sometimes be done on whats called a building notice. Planning will require drawings and Building Reg approval. A Building Notice will form part of Permitted Development and you may only have to notify local council.


Answered 18th Feb 2011

“Velux versus dormer?” As an ex Velux Technician I would say all the previous posts are valid. Cost is always a factor; extra room can be of benefit if the dormer conversion is of sufficient size.

A Velux will always beat a dormer regarding the amount of light entering the conversion, simple the sun is high in the sky, and the angle of a dormer (upright) will spread light in a smaller area, a Velux on a slope will accentuate natural light into the whole room as the angle is sloped.

You can fit a both a dormer and Velux system together by combining benefits of both. they manufacture combination roof windows and vertical elements, best of both worlds!


Answered 11th Jan 2012

Hi there velux windows is by far the cheeper option , but it depends if its extra light or extra space that your after ,


Answered 17th Feb 2011

Hi i would always say velux as long as you have plenty head room and space. velux windows are far cheeper than dormas and give you a lot more light but some times you have to put a dorma on to give you more space


Answered 17th Feb 2011

the dormer also givs you extra space and headhieght which is important if the conversion is to be occupied


Answered 17th Feb 2011

As already mentioned velux in simple terms is a window in the roof and a dormer is an extension to the roof, consider that a dormer may need planning permission and velux often doesn't.


Answered 17th Feb 2011

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