Hip-to-Gable Loft Conversions in Cambridge

A hip-to-gable conversion only applies to one kind of house: one with a hipped roof, where the roof slopes on the end as well as at the front and back. Semi-detached, detached and end-terrace houses often have one; a mid-terrace almost never does. If yours is hipped, this is usually the option that gives the most usable room, and it is the only one of the three common loft types where the main job is masonry rather than carpentry.

For budgets by conversion type, our loft conversion costs guide sets out published Cambridgeshire ranges and explains why the sources disagree with each other.

What it involves

The hipped end of the roof is taken down and rebuilt as a vertical gable wall, carried up in blockwork or brick from the existing wall below. The roof structure is then extended across to meet it. Where a hip slopes away and leaves a triangle of unusable space, a gable gives you full height right out to the end wall.

It is nearly always paired with a rear dormer. On its own a hip-to-gable gains height at one end; combined with a dormer across the back you get a room rather than a corridor. Most of the schemes we price are the two together, and it is worth asking for both to be quoted even if you only expected one — the scaffolding, the roof opening and the structural work are largely shared, so doing both is much cheaper than doing them in separate years.

It is a masonry job

This is the part that separates a hip-to-gable from the other loft types. You are building a new external wall at first-floor level and above, tied into the existing structure, and it will be visible from the street for the life of the house.

That makes brick matching a real consideration rather than an afterthought. New brick against a weathered wall always reads cleaner, and the courses have to be set out to line through with the existing so the horizontal lines of the house carry across. Our gault brick matching case study photographs exactly this problem on a Victorian terrace, and the brickwork page covers bonds, sample panels and what can and cannot be matched.

The new gable also has to be tied properly into the existing masonry and restrained by the new roof and floor structure. A gable wall is tall, thin and exposed to wind, and the restraint straps that hold it are not optional.

The neighbour, if you are semi-detached

On a semi, a hip-to-gable changes the shape of half a pair of houses. Two things follow. The first is planning: the officer will look at whether the result reads as a balanced pair or as one house that has grown a lump, and some councils resist it on prominent corners. The second is the Party Wall etc. Act 1996 — building up off or cutting into the party wall engages it, and notice has to be served before work starts.

Raise it early and in person. A party wall matter goes far better as a conversation with the neighbour than as a letter from a surveyor, and a schedule of condition on their property protects both of you if a crack turns up later.

Floor, structure and stair

As with any loft conversion, the existing ceiling joists are not a floor — they were sized to carry a ceiling, not people. A new floor structure goes in first, sized by an engineer and inspected by Building Control, and the finished floor level sets the head height above and the ceiling height below.

The stair is the same constraint it is on every loft: it needs head height along its whole length, it has to land somewhere sensible, and the loft normally becomes part of a protected escape route, which affects doors and glazing on the floors below. Our Building Regulations guide explains how that runs alongside the build.

What tends to go wrong

The gable priced as carpentry. A quotation that treats the new end wall as a framing job rather than a masonry one is usually a quotation that has not thought about scaffolding, brick matching or restraint. Ask what the wall is built from and how it ties in.

Assuming permitted development. Hip-to-gable work uses a lot of roof volume, and combined with a dormer it can take a scheme over the limit. It is also removed as a right on some estates and in conservation areas. Establish it first — see our permitted development guide.

Leaving the neighbour to find out. A party wall dissent does not stop the work, but it appoints surveyors and adds weeks. It is avoidable.

Common questions

Does my house have a hipped roof?

If the roof slopes down on the end wall as well as the front and back, rather than the wall carrying straight up to a point, yes. Send a photograph of the end elevation and we can tell you in a minute.

Do I have to do the dormer as well?

No, but most people do, and the combined job costs far less than the two separately because the scaffold, the roof opening and the structural work overlap.

Will the new brickwork match?

Closely, rarely perfectly, and we will tell you honestly what we think it will look like before you commit. A sample panel settles the question better than a conversation does.

Will it need planning permission?

Sometimes yes, sometimes no. It depends on volume, on your property and on where you live, and it is the first thing to settle because it shapes the whole design.

The other two types

A dormer conversion is the usual partner to this work and the right answer on its own where the roof is not hipped. A rooflight conversion is the cheapest option where the loft already has the height. The loft conversions page covers how we run all three.

Send a photograph of the end of your house and tell us what you want the space to do. We aim to respond to every enquiry within one working day with the most useful next step.