Extension roof ideas: 8 Roof Design Ideas for Extensions

Roof extension ideas – Grand Designs Magazine : Grand Designs Magazine

The government’s recent extension of permitted development (PD) rules – allowing homeowners to add an extra storey on to a house or apartment – has inspired some creative roof extension ideas.

Unused roof space may provide an innovative solution to extending a home, especially on a small urban plot where other forms of development are difficult or costly – and architects are devising extra-storey and loft-conversion designs that maximise every centimetre. From spacious bedrooms to perfectly situated bathrooms, open-plan living areas to upside-down layouts, almost anything is possible.

Grand Designs magazine takes a look at 10 brilliant roof extension ideas…

1. Rooftop orangery

This third-floor living/dining room was built for a retired doctor and avid art collector on top of his two-bedroom home in Marlborough Yard, Archway, north London.

‘The owner already had a lush roof garden, which needed a light-filled space similar to an orangery,’ says the architect, Kerem Aksoy of A2studio. ‘The 17.5sqm glass box brings in light, has views of the roof garden and surrounding rooftops, and contrasts with the period character of the house.’

The cement panel walls of the solid central section provide display space for art, and an internal staircase leads down to the lower floors. This modern roof extension idea, which cost £70,000, was completed under permitted development. 

Photo: Rick McCullagh

2. Bird’s nest bathroom

This compact bathroom with a view is in a contemporary roof extension, which is clad in black fibre cement panels with a projecting oriel window. It sits on top of a rear extension to a two-storey Victorian apartment in Haringey, north London.

The bathroom measures just 7sqm and was relocated from its inconvenient former position on the floor beneath the two bedrooms. Kerem Aksoy of A2studio came up with innovative ways to maximise the space for the owners, an IT software architect and a yoga instructor, who have dubbed their new addition the Bird’s Nest.

Bespoke timber doors fold back to appear as if they are part of the wall and to make room for a full-height shower with the floor level stepping down inside the cubicle. ‘An electronically operated rooflight provides ventilation and draws in daylight,’ says Kerem. The project cost £140,000 in total.

Photo: Agnese Sanvito
Photo: Agnese Sanvito

3. Another level

Husband and wife architects Jan and Liani Douglas of Douglas & Company extended and remodelled Arklow Villa III, their Victorian cottage in Green Point, Cape Town, South Africa, on a budget of £100,000. ‘We wanted to turn an insular single-storey home into a light-filled two-level house,’ says Liani. ‘We also wanted to retain the soul of the house, as the old dame had real personality pre-renovation, although she was in dire need of a facelift.’

From the front, the two-bedroom semi-detached property appears almost unchanged, except for the addition of two new dormer windows in the roof. The ground-floor layout has remained the same, but with the addition of a small bathroom and staircase.

At the back, the new first floor increases the overall size of the house to 140sqm, and includes a bedroom, bathroom and study. The latter overlooks the living area below, and opens onto a terrace with views towards local landmark Signal Hill. 

Photo: David Southwood/Douglas & Company

4.  Modern mansard

There were plenty of things to consider when turning a traditional terraced house in Hackney, east London, into a streamlined contemporary home that would sit happily alongside its neighbours. The owners, a professional couple, even considered selling up and buying a new-build before they decided to enlist the help of architect Patrick Abrams of Applied Studio.

He got planning permission to update the three-bedroom home by stripping out the structure from the rear, adding a glazed side extension and a 26sqm zinc-clad mansard roof extension. The loftspace bedroom and marble-clad en suite bathroom includes a dramatic frameless skylight.

‘A bold choice of materials was crucial to the success of this project,’ says Patrick. ‘Large expanses of glazing and skylights really opened up the space and created a relationship between the house and the outdoors. The loft extension’s big picture window, which has a seat beneath, makes the perfect reading spot with views over the garden.’ The project cost £400,000.

Photo: Nicholas Worley

5. Lofty ideas

A Japanese-style timber bath overlooks the woodland from the new loft level of a Victorian terraced house in Camberwell, south-east London. The four-bedroom home belongs to architectural photographer Edmund Sumner and architectural writer Yuki Sumner, who live there with their two children.

Keen to avoid a series of cramped, boxed-off spaces, the couple worked with architect Simon Astridge of Szczepaniak Astridge on roof extension ideas to create a retreat from their busy lives. ‘I liked the idea of a bath with a view – something familiar from my visits to Japan,’ explains Edmund.

The loft conversion added 37sqm to the house for a budget of £100,000, which included the renovation of two bedrooms and the addition of a shower room. ‘The house is just outside a lovely conservation area, so we were able to use permitted development (PD) rights to extend into the loft,’ says Simon. 

Photo: Edmund Sumner
Photo: Edmund Sumner

6. Sliding doors

This glass roof extension in south-west London was added by a retired couple who wanted more space to entertain their grandchildren in their top floor two-bedroom apartment. They asked glazing company IQ Glass to create an additional 14.5sqm room to give them a year-round living area.

‘Frosted glass on the north elevation provides privacy from the overlooking roof terraces and met the planning permission requirements,’ says Dan Finnegan, IQ Glass’s contracts director.

The owners wanted to be able to access the roof garden on both sides of their new extension, so it had to be carefully planned with this in mind. Because there wasn’t enough room for a traditional door to open fully outwards, Dan’s team designed a sliding door that glides back across an external wall of the glazed box instead. The project cost £64,000, including solar-control coated glass which limits solar radiation and overheating. 

Photo: IQ Glass
Photo: IQ Glass

Roof Extension ~

Roof Extension: From A TO Z

A roof extension is a great method to create a new space in your home. It gives you several options depending on your specific needs. It also allows you to add height and character to your home.

Take a look at different roof extension ideas below if you’re seeking roof extension done professionally. If you already know what you want, contact Smart Remodeling LLC for a roof extension consultant in Houston, Texas.

Roof Designs For Extensions

Many flat roof designs may be found in books, magazines, and online to help you with your extension project. A flat roof, when done correctly, looks modern as well as being dependable. 

Here are a few of the most popular roof extension trends:

Shed Roof 

The simplest approach is a single slope that connects to the old house at its highest point and slants down to the addition’s exterior wall. It’s simple for the contractor to construct and affordable for the homeowner. The downside is that it makes the extra room appear to be an obvious addition. 

This can lower the value of your home renovation, especially if it’s visible from the street. Shed roofs over living rooms are now prohibited in an increasing number of affluent towns.

Gable Roof

A gable roof expansion consists of both a new roof and a first-floor addition. The pitch is steeper here, and the hips are converted to gable ends, resulting in a large amount of additional floor space upstairs. Your gable roof will add visual appeal and character to the home. This is if it is matched to the angle and proportions of other rooflines on the house, making the addition look like an asset that fits with the house.

Flat Roof Extension

Flat roofs don’t have to be perfectly horizontal; they can be at any angle. They’re simple to install and offer extra features like the possibility to add solar panels or air conditioning to your roof. Some homeowners even go so far as to build an extra living space up there.

Pitched Roof Extension

A pitched roof gives you more height without making your home look boxy or oppressive. It can be made to complement your home’s current appeal while also altering it from its prior appearance. These angled ceilings can also make room for new, beautiful windows and more glazing.

First Floor Extension

Many modern homes have hipped roofs with a short pitch, leaving little space for a loft or storage. Depending on your goals and needs, Smart Remodeling LLC can help you do two things here. We can either create a loft extension within the existing roof space or entirely remove the old roof and replace it with a new first story.


A dormer is a small gable roof that protrudes from the main roof at a 90-degree angle, usually to house one or more windows. A dormer effectively raises the ceiling where you would otherwise have low eaves. 

This is handy if you’re increasing the top level of your home. And one or more dormers can be used to dress up and connect the roofs of a house and its addition together. (Designing a Roof Addition, 2020)

Glazed Roof Extensions 

Glazed roofs are made up of a large expanse of glass. They are a wonderful way to flood your expansion with natural light and create a sunroom-style environment. These areas can be used as a second kitchen, studio, or home office.

Garden Roof Extension

The green roof, which allows homeowners to create a garden on their roof, is perhaps the most modern of all roof designs. Green roofs are becoming a more popular choice among homeowners who want to stand out. This is because they are both ecologically responsible and aesthetically beautiful.

First Floor Over Ground Floor Roof Extension

By extending your home’s first floor over the ground floor, you can add more living space upstairs. This can be accomplished by extending the first floor beyond the existing external wall. The result will be a covered patio and entrance porch that greatly expands the floor area of the room above. (Refresh Renovations, 2021)

Things To Consider Before A Roof Extension

Depending on your home renovation needs, a roof extension onto your home can provide you with more space. Room additions such as a dining room or a home office are possible to achieve. You can also create big additional rooms or enhance existing floor living space, such as enlarging a kitchen.

Here are some pointers to help you decide which solutions are best for your expansion project.


The price of your chosen roof extension ideas and materials will undoubtedly consume a significant chunk of your money. You must be open and honest about the amount of money you have set aside for this extension project. It’s an important discussion to have before you start working on your extension.

ProTip Takeaway: Architectural fees, builder’s fees, materials, and building control fees are all included in your budget. They will vary depending on the quality and complexity of the work.


Is the roof you’re installing practical? Consider things like durability, resistance, and suitability. You’ll want something that will last a long time, is durable, weatherproof, and light in weight.


When you spend thousands of dollars on anything, you clearly want it to look great as well as function. However, as with most things, the most expensive options, such as slate or clay tiles, often appear to be the best. For many people, though, a roof is a roof, and unless you can see it all the time, it shouldn’t matter too much because you’ll be below it rather than peering up at it.

Quality Roof Extension

Understand why you want to extend your home and how it will benefit you, your family, and your property. Because of the rising costs and hassles of moving, as well as the uncertainties in the housing market, more people are opting to stay put.

If the goal of the project is to increase the property value, it’s a good idea to consult an estate agent to determine the value potential of your home. Inevitably, there will be a glass ceiling in the region, and your hard work and money may not yield the results you desire.

ProTip Takeaway: Many homes have hidden potentials, and home renovation can improve a home’s comfort while also increasing its market value.

Materials & Design

Now is the time to start thinking about some ideas for your roof extension design. Begin to consider the materials and effects you’d like to use in your creations. Consider your windows, doors, radiators, insulation, and, above all, your roof.

Flat roofs are so sturdy and they’re great for your extension. They are also advantageous as they don’t have any seams, joints, or welds that allow water to sneak in and damage or degrade components.

A durable topcoat is rolled over the top of the strong fiberglass layer to create a fully sealed surface. Water cannot infiltrate the roof if it is installed correctly since there are no weak places or probable failure points. (Canova Roof, 2021) 

Roof Extension Cost

This sort of home renovation requires a budget for the job. The cost will vary depending on the roof extension design. You will find that a flat roof costs less than a pitched roof which is good news in this case.

This is due to the fact that a flat roof requires less structural engineering. It also allows for the use of less expensive materials than a pitched roof.

What pricing to expect depends on a number of factors, including:

  • Location – The costs of living in a big metropolis will be higher than in a small town.
  • Accessibility – How high is the roof extension and how easy is it to get there?
  • Materials – The better the quality of the materials, the higher the price.
  • Size – A small roof will be less expensive than a huge one.

For a single-story expansion, you may expect to pay between $1,500 and $2,000 USD per m2, based on the four factors indicated above.

Meanwhile, a double-story extension is expected to cost nearly twice as much as a single-story extension. If your design idea is complex, you can add another 10% to 15% to your cost. Architect, structural engineer, and other professional costs are required for high-quality construction. (My Roof, 2020)

ProTip Takeaway: If you don’t have a choice, you may have to erect a more expensive pitched roof. Whether it is the less expensive flat roof expansion or not, the design ideas that deliver the best long-term solution are perfect.

Focus on the roofline if you want your addition to appear as an original component of the house rather than an afterthought. Unless you get the right contractor to build the roof right, your addition will look like a tacked-on addition to the side of the house. This will be the case no matter how nicely the rest of the design fits and the materials complement the house.

Average Roof Extension Cost

Average Cost


High Cost


Low Cost



Ready To Extend Your Roof

Are you looking for a professional roof extension expert in Houston, Texas? Smart Remodeling is the best company for the job. We have years of experience in home renovation and roofs extension.

 Our roofs are built to the highest quality standards and provide homeowners with peace of mind that no other product can equal. They’re the ideal complement to any home improvement. To learn more about our services, please visit our website or call us on 832 800 8889.



7 Pitched-roof Extensions to Inspire Your Renovation Plans

If you’d like an extension with added height, plenty of light and lots of character, it could be worth investing in a pitched-roof design. Take a look at these homes to find ideas for your own project.

Mustard Architects

Work a New York loft mood
The pitched roof extension at the side of this Victorian property helped the owners achieve the New York loft-style warehouse space they were after.

The professionals at Mustard Architects designed the extension to blend in with the brickwork of the original building, and the pitched roof gave them extra height without the addition looking boxy and imposing.

Mustard Architects

The sloped glazed roof ties in with the industrial-style ceiling in the kitchen, created by exposing the joists. The builders matched the rough finish of the joists with timber supports on the skylights, then painted everything white to create a light, airy space.

Tour the rest of this loft-style extension on a Victorian home

Fit some space on the side
The owners of this Victorian ground- and first-floor apartment managed to build some extra space at the side of their double-storey extension by adding a pitched-roof section to the ground floor, which finishes below the roof level of the adjacent building.

The new sloped roof section has given them a spacious dining area with a massive skylight above to flood the area with light.

See more of this extension that’s turned a period flat into a spacious home


Go long and large
The pitched-roof extension that’s been added to this property comes out quite far, and has created enough room for a large living room at the back of the house.

The shape of the new edifice, designed by JLArchitecture, looks attractive at the back of the house and gives the owners extra ceiling height without overwhelming the external space.

Paper House Project

Bring in the light
This extension has created a long room that allows the kitchen and dining areas to stretch out lengthways.

To ensure the space didn’t impact on the neighbours, the designers at Paper House Project built it with a pitched roof. The owners now have a spacious new room with plenty of height above. The sloped roof has provided a surface for large skylights, which make the room feel bright and airy.

Add character
If you want to create an extension on your period property without going too contemporary, a pitched roof design is a good solution. The added space at the back of this Edwardian home, designed by Lofts and Extensions, has bags of character thanks to its sloped shape.

The angled ceiling creates space for an attractive set of French windows and additional glazing at the rear that looks completely in keeping with the period house and provides a stunning feature.

Gundry & Ducker

Create a contrast
Rather than try to blend the extension in with the rest of the building, the architects at Gundry & Ducker have created something completely different. The black-clad space with an asymmetrical pitched roof looks striking at the back of the Victorian property.

Gundry & Ducker

To add even more interest, the architects have replicated the sloped form with an angled black fence at the back of the garden.

GOAStudio London residential architecture limited

Connect with the garden
Not only has this pitched-roof extension helped to provide extra space without blocking light for the neighbours, it’s also helped the owners create a connection with the garden. The angled design, created by GOAStudio, protrudes over the patio to form a pleasing shape when viewed from outside.

GOAStudio London residential architecture limited

From inside, the sloped ceiling attractively frames the garden, while extra glazing above the bifold doors maximised the light.

GOAStudio London residential architecture limited

There’s even an extra glazed section at the back, looking onto the side return, to bring in more light.

Tell us…
Are you planning a pitched-roof extension? Have any of these projects given you food for thought? Share your ideas in the Comments section.


Zwickau bis Gera I Wir machen Ihren Garten zum perfekten Erholungsraum


Zwickau bis Gera I Wir machen Ihren Garten zum perfekten Erholungsraum

8 Roof Extension Ideas For 2022

A roof extension can help make your home look more stylish and unique while also providing functionality. However, it’s important to think about how this additional space will impact both your house’s exterior and interior. Therefore, you should always make sure to establish your goals and budget before undertaking this type of project, regardless of the size, color, number of floors, types of windows, and construction material of your home.

8 Roof Extension Ideas

As we begin a new year, there are several roof design ideas you can consider to make your house stand out. Here are eight roof extension ideas for 2022:

1. Catslide Roof (Aesthetic Extension)

This design consists of a roof slope that extends downwards further than a second slope. A catslide roof is an excellent option if you own a cottage, as the tiles and shape can give your home a beautiful aesthetic. This type of roof can also match older parts of your home.

2. Winged Roof

As its name suggests, this type of roof is shaped like wings and is an excellent design choice for a modern home that has a lot of windows and vibrant colors. This extension generally goes out (upwards) and down (on the side of the house) and gives off an almost artistic feel, as if it were a sculpture. As with any other roof, just make sure that the color fits well with the rest of your property.

3. Unique Twisted Roof

A twisted roof is a sound design choice if you have a two-story home with a staircase of a certain height and windows that are installed in a specific way. Therefore, it’s both an aesthetically unique and pragmatic option for a roof. A twisted roof can also be appreciated from several angles.

4. Metal Roof (Single-Story Extension)

A metal (e.g. stainless steel or copper) roof on a single-story extension can look aesthetically pleasing opposite aluminum windows and composite wood, or even stone. This is especially true of older homes, so be sure to consider this side extension if your house was built many decades ago.

According to State Farm® Insurance, metal roofs have great longevity: they can last between 40 and 70 years, depending on the specific type of metal. By contrast, traditional asphalt roofs typically last no more than 20 years. According to FindAnyAnswer, the average cost of a single-story roof extension can be anywhere between $1,350 and $2,100 per square-meter, depending on your chosen materials and design type.

5. Duo Pitch Roof (Modern Extension)

A duo pitch roof is also an excellent choice for cottages. This type of extension, which will give your home a contemporary look, can feature steel and significant glazing, or it can consist of stone slates. Consider a duo pitch roof if you feel that your house is rapidly aging.

6. Monopitch Roof (Cantilevered Extension)

A monopitch roof only has one slope and typically features a single gradient. This is an excellent choice if you have a preference for simpler designs. A monopitch roof extension is also a great option if you live in the countryside, as it allows you to enjoy rural landscapes more. However, keep in mind that monopitch roofs are often expensive because of the level of engineering required to build them.

7. Flat Roof Extension

A flat roof extension may initially sound simple but can sometimes be the best option for a home. For example, if you have an old (e.g. 19th-century) art-deco-style home, a flat roof can mark a sharp contrast with a pitched roof, especially if it’s a dark color. Flat roofs also typically include a minor pitch for water draining.

8. Twin Gable Extension

A twin gable roof design features two triangle-shaped frontages and has the appearance of two identical (or similar) “peaks.” This is different from a crossed-gable design, which features two triangular roofs that are perpendicular to one another. A twin gable extension can look great in combination with concrete tiles, white render, and glazing. Windows are typically installed on gables so that natural light can enter a home.

All of these roof extensions can help your home stand out in 2022. Keep in mind that certain types of roofs, such as metal roofs, are more durable and eco-friendly. However, metal roofs are not as affordable as other types of roofing materials, such as asphalt and wood. They are also not as durable as clay, concrete, or slate roofing tiles, which can last 100 years or longer, according to the National Association of Home Builders®.

Get Quality Roofing Extensions From Adelphia Exteriors

Speak to the professionals at Adelphia Exteriors to learn more about different types of roof extensions. We’re a home improvement company dedicated to providing high-quality services such as roofing, window installation and replacement, and siding to both residential and commercial clients throughout the DC Metro Area.

Regardless of the shape or materials, you want for your roof, our team will work tirelessly to install an extension in an efficient way so that your home looks unique and is protected from adverse weather events. Call Adelphia Exteriors today at (703) 386-7357 or contact us online to request a free roof evaluation.

Single Storey Extension Ideas: The Ultimate Guide