Why Have a Dormer Extension?

Why Have a Dormer Extension?

Are you considering a dormer loft conversion? This article tells you everything you need to know about these type of extensions.

In simple terms, a dormer extension is a type of loft conversion.  The best way to imagine this is a structure in the shape of a box coming out the side of your roof.  This method expands the usable space within your loft space so you can squeeze more rooms into it.

Requirements for Dormer Extensions

Do Loft Conversion need Planning Permission?

Planning permission is only required when extending or altering the roof space, and it exceeds specified limits and conditions.  Your architect or building can help you decide what is required.

Do Loft Conversions need Building Regulation Approval?

Yes, all loft conversions require buildings regulation approval.  This also applies even you do not require planning permission.  When you start your extension a Building control surveyor will inspect your work at various stages.  Once approved they will issue you with a certificate on final inspection.

How many Additional Rooms Can I have?

  • The shape of your roof can influence how many potential rooms you can have.  If you have an awkward shaped roof it may be difficult to add an extra room without it looking strange.  Ideally you want you loft conversion to look natural as possible.
  • Usable space that a loft conversion can provide is based on a head height of at least 2.2m.  This is the distance between the bottom of the ridge timber to the top of the ceiling joist.
  • What is your current roof pitch angle? Higher pitched roofs enable more additional loft conversion space.

Loft Conversion Process

  1. First hire an architect.  They can tell you what your options are regarding rooms and space.  They can design the loft conversion using CAD, and calculate the necessary supporting steel beams you need.  Architect drawing are very details.  The builder you hire will refer to these drawings throughout the project.
  2. Your architect will draw up your detailed loft extension plans for you to see.  Once you agree on the ideal plans, they can then be sent to planning permission (if necessary).  If planning permission is not needed, they can then be send directly to building control.
  3. Once building control approve your drawings, you are then ready to build.  However, building control will visit do site visits throughout the project to ensure it is being made to the drawings.  And that all current building regulations are met.  Building regulation surveyors have the power to decline or approve a certification for your new loft extension. 

Types of Dormer Loft Extension

Flat Roof Dormer

This is the most popular type of dormer extension in the UK.  The extension is boxed shaped with a simple flat roof.  This is also the cheapest type of dormer to install.  It also offers the largest amount of usable space.

Shed Dormer

Often used in homes with a gable roof, shed dormers have a flat single planed roof.  They are sloped downwards at an angle. shallower than the main roof.  The downside is that they usually require different roof sheeting to that of the main roof.

Gable Fronted Dormer

Also known as a “dog-house dormer”, they are a more attractive option when it comes to loft extensions.  They consist of a gable wall extension which is built up to the existing ridge line.  Then a new roof section is built outwards to the new gable end.

Hipped Roof Dormer

These are similar to a gable fronted dormer, but has three sloping planes of a hipped roof converging at the ridge of the dormer.  They are the most attractive option, but can reduce the amount of extra space compared to flat roof dormers.

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