What is a two-storey extension?

A two-storey or double-storey extension is a type of home improvement project that will add another floor to an already existing building. This means that you’ll also need to find out about permitted development as well as any existing structural limitations. Alternatively, if there are no structures inside the dwelling, then you can just extend the roof line and build more rooms. It’s important to note that the size of the extension will always dictate how much work is involved.

Double-storey extensions – What are the advantages?

As mentioned earlier, a double-storey expansion is often seen as the best way to increase the value of your property. Adding an extra floor means that you can easily create bedrooms or a double-storey garage extension or even study areas without having to worry about fitting them in with other elements. You can also make use of the space above your kitchen to provide storage solutions or maybe an office area. These types of additions are great for families too, who may want to start their own business from home.

If you’re thinking about adding a master bedroom to your current house, you should know that you might need some sort of loft conversion. This involves building new stairs and access points to get up to the second floor – all while maintaining the integrity of the rest of the house. Similarly, if you’ve got a spare room then you should consider converting it into a self-contained flat rather than just using it as storage.

If you think that a double-storeys is the answer to your problems, then check out our top tips below to see what we recommend.

Boost your house’s value with these double-storey extension ideas

Double-storey extensions offer great space, but there are many different styles to choose from. There are many options for double-storey extensions, including timber, steel, concrete and glass. Building an extension with two storeys gives you extra living space without having to move house

1. Creating a self-contained guest room or multi-generational dwelling

With today’s busy lifestyles, people often find themselves spending more time at work or with friends than at home. Adding a second or even third storey to your home can make it easier to accommodate these activities and enable you to enjoy the best bits of both worlds. The added height means that guests can easily pop in and out of the house, making them more comfortable than traditional guest accommodation, which is almost always down a flight of stairs and in a separate wing of the house.

It’s also possible to create a multi-generational home where grandparents live above the main family residence. Many parents want their children to remain close to home as they grow up, but don’t want to sacrifice the benefits of their own private space; likewise, grandparents may want to spend more time with their grandchildren.

2. Add a double-storey side extension

A double-storey side addition expands outward in all directions, giving a house a new dimension and larger footprint. Extra bedrooms can easily be added to create a better family living environment. Without having to tear down walls or floors, adding a second floor gives a house a modern feel. As a result of this extension plan, there will be an additional bedroom and bathroom upstairs, and the ground floor will become more spacious in a split-level design.

3. Use a double-height extension as a makeover for an old house

Double height extensions give you more room without spending too much money. They are great if you want to build a new kitchen and dining room. An extension will improve the quality of life for you and your family.

A double-height extension offers the perfect solution, offering more room, taking advantage of the view and giving you a stylish addition to your home.

Double-storey additions are very desirable to homes of all sizes because they add so much space. It’s no wonder that they are such popular additions to homeowners, especially those who plan to sell their property.

If you are planning to sell your home or relocate soon, then building a double-storey extension could be a smart move. Not only does it increase the size of your home, which will help sell it quicker, but it also adds style and function to your current dwelling.

4. Make odd floor plans work for you 

The addition of a second storey creates opportunities to rethink awkward floor plans. A two-storey addition can create a bright, open feeling throughout the home. Double height spaces provide ample room for entertaining friends and family too.

5. A quaint oak frame extension

This project shows how a simple double-storey extension can create extra living space without compromising the original character of the house. An oak frame extension was constructed to include a sunroom below and a view-filled bedroom above. The home’s period style was maintained while incorporating a great deal of glazing.

A well-thought-out extension can add value to any property. This type of extension will cost less than most other options available.

6. Modern two-storey glazed extension

A new double-storey extension gives you extra living space without having to build upwards. Adding a glazed double-storey extension to a basement will enhance the space, and increase the amount of natural light,  particularly if the extension looks out onto the garden space.

Whenever possible, choose expansive glazing over intricate framing, maximizing light and creating a modern aesthetic. You can increase your home’s living space by adding this double-storey extension.

7. Build a two-storey glass box extension in a small area

This type of construction allows you to add an extra floor above the ground floor without having to demolish anything or take out any walls. Galleries are often built in areas where there is limited access to natural light, which is why they are popular in London and other cities around the world.

This double-storey extension creates new spaces for entertaining guests and relaxing.

8. Contrasting brickwork

This is an example of how to create a contemporary double-storey extension design. Contrasting brickwork is a good way to add interest to your home.

This type of extension is popular nowadays. You must be careful and possibly get your local council’s planning permission, especially if you are living in a conservation area if you want to do this.

Despite having the same size and tone, the bricks here are painted in hues that may clearly differentiate the old from the new.

9. Extension designs for period properties must be sympathetic

Extension ideas for period properties should be sympathetic to the original building. Designing an extension that blends into the style of the original building is a must. Ecofriendly extensions are good options for period properties.

10. Build a connection between two buildings with a glazed extension

This is a double-storey extension option that connects two separate parts of a property. You may want to create an open plan space between the two houses with a breathtaking double-height design reflecting the roof pitch of the main structure, linking the two wings together. The light-filled area doubles as an entryway and comfortable living space that makes it possible to enjoy the garden year-round.

If you want to connect two existing period properties, this may be the solution that planners will approve.

11. Make an impression with a distinctive cladding

Are you looking for top-quality double-storey extension design ideas? Metallic cladding gives an instant impression of luxury and sophistication. Cladding should complement your existing architecture rather than overpowering it.

An extension with metallic cladding will look stylish and smart. In any case, be careful when choosing finishes – they can be very costly and your house will look very different from other houses. To find out whether your home’s value will be damaged by this activity, speak to an estate agent first.



The double-storey extension cost can vary substantially, depending upon what kind of fixtures and finishes you choose. For example, installing high-end cabinetry might require twice the expenditure of choosing basic cabinets. However, you also pay for convenience – the time and effort involved in completing an extension project are considerable. At the same time, the design options and features within an extension offer unique opportunities for creating a space specifically suited to your lifestyle. 

House extensions are complex projects that should be planned carefully. They require careful consideration of how they fit into the plan of the existing house. A qualified building company should be able to provide advice on how to best design and build them.