All You Need to Know About Hip-to-Gable Loft Conversions

A classic example of a hip to gable loft conversion, whereby a hip roof has been extended outwards to form a gable roof.

The second installment of a 4-part series, this blog is all about hip to gable loft conversions.  Bizarre names aside, hip to gable loft conversions are popular the World over.  Extremely versatile, they are often combined with other styles of loft conversion for maximum space and utility.


HLN Engineering Ltd has overseen the design and construction of a number of hip to gable loft conversions.  If you’re tempted by the prospect of a hip to gable loft conversion, but unsure of the design and construction implications, then this mini-guide is for you.


Let’s dive in…

What Does Hip to Gable Mean?


The term hip to gable derives from 2 different styles of roof: hip and gable.


Hip roof-


A hip roof slants on all four sides. It is the strongest of all roof types and therefore highly desirable.


The strength and durability of this style of roof is down to the 4 main support rafters (known as hips) – all four hips are positioned at a 45-degree angle and meet at the central ridge.


A major drawback is that they are more complicated to design and construct than any other style of roof


Gable roof-


Conversely, a gable roof slants only on two sides.  Particularly popular in the USA (they are a staple feature of homes in New England), gable roofs are cheaper to design and construct than hip roofs.


That said, they are not as strong as hip roofs due to a lack of framing support.  They are also susceptible to wind damage.


How are Hip to Gable Loft Conversions Constructed?


As you’ve probably guessed by now, this style of conversion involves transforming one side of a hip roof into a gable roof.


How is this done?


It is a relatively simple process that involves extending one side of a sloping roof outwards.


This is accomplished by removing the part of the roof in question and erecting a triangular shaped vertical wall (the same height as the central ridge) in its place.


The central ridge is then connected to the newly built vertical wall and the open space in-between is filled in with additional rafters, then tiled over.  This process creates the gable portion of the roof.  Voila!


The result is a loft space with a lot more vertical space.


Will I Require Planning Permission?

Once constructed, hip to gable loft conversions can be transformed to incorporate other styles of loft conversion. In this example, Velux windows have been added on either side of the roof.

You’re in luck – planning permission isn’t usually required for a standard hip to gable loft conversion.  This is due to a handy piece of legislation known as permitted development.


Introduced in 2008, permitted development affords property owners the right to make certain structural alterations, without permission from the local authority.  The only caveat is that permitted development does not apply to flats nor maisonettes.


The only time you may require planning permission is if you construct a standard hip to gable loft conversion, then further convert the roof by adding elements of other styles of loft conversion.


For instance, once the hip to gable element of the roof has been created, a bay dormer could be added to the front or rear of the roof.


What are the Benefits?


Compared to other styles, there are a number of benefits unique to hip to gable loft conversions:


  • If you have a detached house with a hip roof, there’s nothing stopping you from converting both sides for maximum space (in fact, it might look a bit odd if you didn’t…). This is known as a double hip to gable loft conversion;


  • The roof alterations required can be designed to fit-in with the exterior motif of your property. More often than not, a well-constructed hip to gable loft conversion will look as if it is an original feature;


  • Another obvious benefit is more living space. This is further increased if you opt for a double hip to gable loft conversion!
 Any Drawbacks?


Unfortunately, hip to gable loft conversions can only be constructed on detached or semi-detached properties due to the requirement of a sloping roof at either end.  For all other properties, consider a mansard, Velux or dormer loft conversion.


If the idea of a hip to gable loft conversion appeals to you, contact HLN Engineering Ltd today on 020 8099 6388 or email us at for an initial consultation.

0 replies

Leave a Reply

Want to join the discussion?
Feel free to contribute!

Leave a Reply

Your email address will not be published.