Why single storey extensions are the best option for most homes

3rd September 2021

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If you’re starting to plan to add an extension to your home, your mind may be swirling with all the possibilities!

There are so many decisions to make to ensure that you achieve an extension that:

  • Complements your home.
  • Is on budget – this is very important!
  • Achieves your goals for what it brings you as a new living space.
  • Does not ‘overdevelop your home’ – this is where you spend (substantially) more money on the extension than what it adds to the value of your home.

The first decision to make affects all of the above, and that is whether to add a single storey extension or go the whole hog and add a double storey one….

Many people immediately think that if budget and other circumstances allow, that they would automatically prefer to have a double storey extension. After all – surely it is better to add as large an extension as possible to your home? However, this is not always the case. There are many reasons why for the majority of homes – and homeowners – a single storey extension may be the best choice.

Here are the top reasons why adding a single storey extension is the best option for most homes.


There is a common misconception that “if you’re building an extension and have gone to the expense of digging foundations, you might as well add an upstairs instead of just having a single storey extension.” WRONG.

While foundations can often be an expensive part of any extension build, it is not always marginally more to add an extra storey. For example, by going from a single storey extension to a double storey, the layout of upstairs rooms, hallways and even stairways may need changing – which comes at considerable cost. The only reason why you should add a double storey extension is if you specifically set out to do this because you need the additional upstairs space. Other than this, any cost is an additional cost, for something you may not need and that will certainly add substantially to your budget. Stick to the single storey unless you really need the extra space upstairs.


This is something to be very wary of. For most homeowners, adding a single storey extension to their home will see it increase in value. This is because adding a single storey extension often allows people to create the modern, open-plan living spaces that are so desirable now to so many families, and this is what adds real value and saleability to a home.

Unless a home explicitly needs another bedroom, this often won’t add the value that people think. And so, all of the expense and additional mess, building work etc. that comes with a double storey extension may not actually add the value you expect.

Take a typical four-bedroom detached home with a separate kitchen and dining room. If the homeowner was to add on a single storey extension and make a large, open-plan room using the existing small kitchen and dining room, this would undoubtedly add great value. This kind of single storey extension project transforms a home from a traditional layout with smaller, separate rooms into a large modern living space that is highly desirable to future buyers. However, as four bedrooms are more than adequate for most families, while adding a double storey extension and an extra bedroom might be attractive to future buyers, it won’t add anything like the value of the open plan living space that can be achieved with a single storey extension.


When adding an extension to your home, along with the extra space you will have, bringing in more natural light is at the top of many homeowners’ wish lists. With a single storey extension, there are many possibilities for bringing light into the room below and the adjoining rooms. These include skylights or lanterns – both of which look stunning and will light up any room. Of course, when adding a double storey extension, the lower floor of the extension cannot have any glazing in the roof – and so misses out on all of that valuable vertical light.

Vertical light is the name given to light that enters a room from above, through glazing in the roof. A room with a vertical light source will be far brighter than one that only receives light via windows and doors. This precious vertical light can only be achieved with a single storey extension.

You must choose what looks best on your home aesthetically. Again, this point is to reiterate that unless you explicitly need a double storey extension, don’t add one. The vast majority of homes look beautiful – even improved – with the addition of a single storey extension. Adding an extension that spans over two floors is far trickier to get right in terms of the external aesthetics and proportions.


The final reason in our list of reasons why a single storey extension is the best choice for most homes is speed. The disruption involved with adding an extension to your home is a concern for many homeowners with most wanting it to be over as quickly as possible. Adding a single storey extension is far quicker than adding a double storey one.

For those wishing to hugely speed up the extension build process, why not take a look at Ultraframe extensions. A new single storey extension can be built and finished in a matter of weeks, as opposed to months. This is because a large amount of the work is done in a factory before transporting the components to be assembled on site. This means that homeowners can benefit from their new single storey living space much sooner than with a traditionally built extension.

Of course, for some homes, and some families, a double storey extension will be the right choice. However, for the vast majority of UK homes and families, single storey extensions are the perfect choice. Single storey extensions can completely transform most homes into stunning, light-filled spaces for the whole family to enjoy.

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