Loft Conversion Types: Your Essential Guide to the Four Main Options

Space is at a premium, especially if you live in the city or a popular suburb. A loft that’s collecting dust could be the answer to your space (and even storage) problems. But before diving in, you’ve got to figure out which type of loft conversion is right for your home. It makes a massive difference in what you can do with the space, how much you’ll spend, and even whether you’ll need planning permission.

Some methods barely change the roofline, flying under the radar of neighbours and councils. Others make a bold statement, totally reshaping your house silhouette. Knowing the four main types—dormer, hip to gable, mansard, and roof light (sometimes called Velux)—can save you serious cash and stress later on.

It’s not just about the look, either. Each type has its own rules about headroom, natural light, insulation, and what you can use the space for. I’m breaking down each option with real-world tips that won’t leave you guessing, so you can start planning without second-guessing every decision.

• Dormer Loft Conversion
• Hip to Gable Loft Conversion
• Mansard Loft Conversion
• Roof Light (Velux) Loft Conversion

Dormer Loft Conversion

If you're after extra space and better headroom, a dormer loft conversion is usually the first option people consider. It’s basically an extension that sticks out from your existing roof, with flat walls and a flat or slightly sloped roof. That means your new room isn’t all cramped with sloping ceilings, so you actually get usable floor space.

The big win with a dormer conversion is versatility. You can turn a dusty attic into a practical bedroom, home office, or playroom without major changes to the rest of the house. Dormers work for most home types—terraced, semi-detached, and detached. They're especially good for 1930s houses or Victorian terraces that don’t have much loft height to start with.

Most dormer loft conversions fall under "permitted development,” so you probably won’t need full planning permission unless you live in a conservation area or want to make the dormer huge. However, you’ll still need to make sure you follow building regulations on things like fire safety, insulation, and access (proper stairs are a must).

• Loft conversion dormers usually add at least 30% more space to your loft.
• They bring in a lot of natural light since there’s room for big windows or even French doors.
• You can pick from full-width, L-shaped, and single dormers—full-width gives you the most extra space.

Here’s a quick comparison of the common features and pros of a dormer conversion:

*If you live in a listed building or conservation area, check local council rules first.

One tip: make sure your neighbours are cool with the plans, especially if their rooflines connect to yours. It saves a ton of time and awkward chats later. A well-built dormer blends in with the street, but the extra space inside makes a real difference in daily life.

Hip to Gable Loft Conversion

If you own a house with a hipped roof—those sloped ends that just don’t give you much headroom—a hip to gable loft conversion might be what you need. This kind of attic renovation involves straightening the sloping side of your roof (the "hip") and building it up to create a vertical wall (the "gable"). You end up with more actual space, making the room feel much less cramped.

This is especially popular on semi-detached and end-terrace houses, since they typically have a hipped roof on at least one side. Detached houses can use it too and really maximize their loft’s potential. The best part? Your new gable wall and extra floorspace can turn a tiny unused attic into a proper bedroom, office, or even a full suite with a bathroom.

One known fact: the majority of hip to gable conversions fall under permitted development, which means you often don’t need full planning permission (as long as you stick to strict limits and don’t live in a listed building or conservation area). But always double-check with your local council because breaking the rules can mean nasty, expensive adjustments later.

“A hip to gable loft conversion can give homeowners up to 50% more usable floor area compared to the original loft, especially where the roof previously restricted movement,” says Paul Taylor, a surveyor with the Royal Institution of Chartered Surveyors (RICS).

If you’re thinking this is a huge job, you’re not wrong. Construction can take between 6 to 8 weeks, and the work will be noisy. But the extra space—plus a big bump in property value—usually makes it worth it.

• Works really well for houses with hipped roofs (like most 1930s semis).
• Usually increases both floor space and potential resale value.
• Often combined with a dormer for even more room and light.
• Make sure your roof structure is solid enough for the change—sometimes you’ll need some steel reinforcement.

If you want a loft conversion that lets you actually stand up, move around, and use the whole space—not just the middle—a hip to gable is worth a closer look.

Mansard Loft Conversion

If you’re chasing maximum space, a mansard loft conversion is hard to beat. This style changes the whole shape of your roof, creating almost a full extra storey with steep sides and a flat top. You see a lot of these in London townhouses and older terraced homes—basically, anywhere space is at a premium and people want that extra big bedroom or a couple of new rooms upstairs.

The main draw? You can get nearly vertical walls, which means more headroom than other options. Think about a proper, usable room instead of a cramped attic. A mansard conversion isn’t subtle though—your roofline gets completely reworked, and it’s visible from the street. Because of that, you’ll almost always need planning permission. Local councils tend to be strict, checking for neighbours being overlooked or the street appearance changing too much.

Here’s what’s involved with a mansard conversion:

• The back or side of your roof is removed and rebuilt so it’s almost vertical (around 72°).
• A flat roof is built on top, maximising the usable space inside.
• Larger windows (often French doors with a Juliette balcony) can be fitted for loads of natural light.

Since it’s the most construction-heavy loft conversion type, this comes with the largest price tag. Expect to pay anywhere from £40,000 to £75,000 or even more if you’re in London or have tricky access. But you’re getting much more space for the money, which can make a huge difference to your property value—sometimes by over 20%, according to recent real estate estimates.

Before jumping in, check your street. Some areas have rules about matching neighbouring rooflines or using traditional materials, especially if you live in a conservation area. And don’t forget: all that extra floor area means more heating, insulation, and even possible rewiring or plumbing if you’re adding a bathroom.

If you need a true extra floor and don’t mind investing, the mansard gives you serious flexibility. Home offices, kids’ bedrooms, or even self-contained studios are all possible. Just be ready for the paperwork and a bit of upheaval during the build.

Roof Light (Velux) Loft Conversion

If you want extra living space with the least amount of fuss, a Roof Light Loft Conversion—also called a Velux conversion—is the way to go. It’s the simplest and usually the cheapest option because it works with your existing roof structure. No major alterations and, in most cases, no planning permission needed. You just install large windows or roof lights (often Velux branded) into the slope of your roof and upgrade the floor, walls, and insulation.

The catch? You need enough head height already in your attic. Supposedly, around 2.2 metres at the tallest point is a must for comfort. If your house was built after the 1960s, you’re more likely to have enough space. With older houses, always measure before getting excited.

Here’s what a Roof Light Loft Conversion brings to the table:

• loft conversion that keeps the outside of your home looking pretty much the same—no sticking out bits or dramatic new rooflines.
• Makes the most of natural light with big roof windows, so the new room feels bright and welcoming.
• A lower chance of needing planning permission compared to other types, because there are fewer visible changes to your house.
• Shorter build time—sometimes just 3 to 5 weeks if everything goes smoothly.
• Great for bedrooms, home offices, or hobby rooms that don’t need loads of headspace.

Wondering about the costs and practicalities? Check out some rough averages below:

If you want to boost your home’s value without turning your street into a building site, this type is hard to beat. Most contractors recommend going heavy with insulation since the roof can be a real heat escape route. Also, check if your joists can handle extra weight—sometimes a structural engineer needs to give the green light.

One last tip: talk to your local building control even if you think you’re in the clear. Regulations can vary, and you’ll need to follow rules for things like fire safety and proper stairs. Don’t just trust the internet—double check before that first swing of the hammer.