Hip to Gable Loft Conversions – All you need to know

Hip to gable loft conversions are becoming an increasingly popular way to create extra room in a property. But before committing to extending your home with this type of loft conversion, there are a number of things you need to know. Here, we take a look at what hip to gable loft conversions actually are, any limitations or restrictions you might need to consider, and also how to calculate the volume of these loft extensions.

What is a hip to gable loft conversion?

Most properties have a regular, ‘hipped’ roof with a sloping side. This means existing loft space is often limited, making it difficult to create a loft conversion without extending your property. This is where hip to gable loft extensions come in.

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This type of loft conversion extends your property on the sloping side, effectively replacing the sloping roof with a vertical wall (the gable) at the end to the same height as the ridge, and filling in the space in between. The added space can then be used for whatever purpose you see fit, although typically its big enough for an office, play area or an additional lounge space.

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Hip_to_Gable_Loft_Conversion_-_Gable

If your property has two sloping sides and you replace them both with vertical walls, it will be a double hip to gable loft conversion and will obviously provide you with even more additional space.

Do I need planning permission for a hip to gable loft conversion?

Since 2008, it is not normally necessary to get planning permission to create a typical hip to gable loft extension. In 2008 laws were brought in to allow homeowners in the UK to conduct a small amount of development or extension work (known as ‘permitted developments‘) to their property without notifying their Local Authority.

However, it’s always worth contacting your Local Authority to check what its planning policy dictates and how that will affect your planned extension, as some councils have not yet approved the legislation. You may also find that you need planning permission if you have carried out a number of permitted developments, such as a previous extension or a conservatory, on your property already, or if the volume added by your conversion is particularly large. (To work out how big your conversion will be, take a look at our hip to gable volume calculator further down the page.)

Is a hip to gable loft conversion suitable for my property?

If your property is detached or semi-detached, and has a hip-end roof, then this sort of loft conversion is certainly a viable option for you. They are also suitable for many bungalows and chalets too.

The attraction of this type of loft extension to bungalow owners is obvious, thanks to the additional living space generated. However, extra care should be taken when deciding whether to extend a single storey building in this way, as sometimes the structure will not be able to cope with the added strain a conversion will put on it.

If your property is a mid-terrace, then a hip to gable is obviously not possible as there is no hip-end to the roof. If yours is an end-terrace, however, a loft extension of this type could be viable.

Whatever style your property, the roof must be of sufficient height between the top ridge and the joists of the ceiling below to allow the creation of sufficient living space. If the original height is not there in the first place, then a hip to gable loft conversion will not be viable or cost effective.

Hip to gable loft conversion volume calculator

To work out the volume of your hip to gable extension, you will need to know:

A – The depth of the main roof (i.e. the length from the front wall of the building to the back wall of the building)

B – The height of the main roof

C – The distance from the ridge to the eaves in the plan

Once you’ve got these measurements, you’ll need to carry out three calculations to work out the volume:

Volume of triangular prism:

= Area of triangle x length

= AxB/2 x (Cx2)

Volume of the pyramid:

= Base area x 1/3 height

= (Ax(Cx2)) x 1/3B

Volume of the additional hip to gable segment:

= Prism x pyramid /2

How long does it take

Obviously the length of time a hip to gable conversion will take depends upon the scale of the project and the size of the team working on it. Typically, you can expect a five or six week timescale.

Please feel free to get in touch with Abbey Lofts and we will be happy to provide any extra information about loft conversions.