When you’re looking at property listings, now and again you’ll probably come across the term ‘duplex’ – you might know what this means, but there are some different interpretations to be aware of. So, once and for all, what is a duplex?
The clue is in the name, for any linguists out there! The word ‘duplex’ originates from Latin, blending duo meaning two and plex meaning fold or layer.
In this guide, I explain what a duplex is in the UK, the differences compared to its meaning in the US and how duplexes differ from maisonettes. I’ll also cover the pros and cons of a duplex in comparison to regular flats or houses.
Key takeaways: What is a duplex? (UK)
- Duplex apartments cover two floors within one property, using internal stairs to connect living spaces below and bedrooms above
- Residents enjoy more space and a layout that provides a house-like level of privacy while still benefiting from shared building amenities
- This is not to be confused with the US version of a duplex – in the US, a duplex is a whole building divided into two separate living units, each with its own entrance
- Both maisonettes and duplexes are multi-level, but maisonettes usually have a private entrance and sometimes a garden, whereas duplexes often have communal entrances in blocks
What is a duplex apartment?
A duplex apartment or flat in the UK is a flat that is spread across two floors within the same unit, connected by an internal staircase.
This style provides more space and privacy than a single-level flat.
Here are the typical details:
- Two levels connected by internal stairs
- Living spaces (such as the kitchen and lounge) are typically on the lower floor, with bedrooms and bathrooms upstairs
- A balance between the spaciousness of a house and the benefits of a flat
- Duplexes are more common in cities, where there tends to be less space for houses and there are more apartment blocks
There is some debate over whether an apartment with a mezzanine is still a duplex. However, the term is used quite loosely – especially in newer, open-plan designs.
A mezzanine is an intermediate floor that is partially open to the floor below and does not extend over the entire area. It is not always a full second story and often has lower ceilings.
An apartment with three floors is sometimes called a triplex.
What is the difference between a duplex in the UK and US?
In the US, a duplex is a whole building divided into two separate living units, each with its own entrance. In short:
- UK duplex = a single flat on two internal floors
- US duplex = two separate homes in one building, each with its own entrance
In the US, these homes are either side by side or one above the other, sharing a common wall but serving as completely different homes.
So, if you’re wondering – what is a duplex house?… It’s not really a common term in the UK.
Duplexes in the UK tend to be two-storey flats, but the UK equivalent of a US duplex is a semi-detached house. Each home has its own entrance and is joined to a neighbouring property by a single shared wall.
For more details on these shared walls, read this – What is a party wall agreement?
Duplexes vs maisonettes
They are both multi-level properties, but duplexes and maisonettes are not quite the same thing. They have important differences:
- Duplexes: You typically access a duplex flat via a shared entrance or hallway with other flats in the same block
- Maisonettes: In contrast, a maisonette is also usually over two floors – but typically has its own private, direct entrance from the outside, often making it feel more like a small house
‘Maisonette’ comes from the French word meaning ‘small house’ and accordingly, they combine some elements of both flats and houses.
Some maisonettes include a private garden, which a duplex is unlikely to have unless it is a ground floor flat.
Maisonettes are sometimes converted period houses, divided into two separate flats with one on each storey. Upstairs maisonettes may include a loft, while downstairs maisonettes may have some outdoor space.
For more details, please read this separate dedicated Fine Living guide – Maisonette meaning: What is a maisonette?
Duplex advantages
- More space: Duplexes are usually larger than single-level flats, providing house-like layouts with separate zones for living and sleeping
- Privacy: The split-level design allows for better separation of activities and enhanced privacy, especially with bedrooms on a different floor
- House-like feel: Residents enjoy the feel of a house while still benefiting from the amenities and security of apartment living
- Natural light and views: The multi-floor layout often means more windows, improved light, and sometimes better views, especially if located on upper floors
- Flexibility: The layout is versatile for home offices, guest rooms, or even separating family and work lives
- Greater individuality: Duplexes can be easier to personalise, with more options to arrange rooms according to your lifestyle
- Strong rental appeal: The extra space and privacy attract premium rents and a wide range of tenants, making duplexes a good investment for landlords
Duplex disadvantages
- Accessibility: Duplexes feature internal stairs, which can be a disadvantage for those with mobility issues compared to regular flats
- Higher costs: Duplexes often cost more to buy or rent than single-level flats
- Utility expenses: The need to heat, light and maintain two floors may mean increased utility costs compared to a typical flat
- Privacy: While duplexes can feel more private than standard flats, compared to a house, they still share some communal areas and walls with other residents in the block
- Limited outdoor space: Duplexes typically have less outdoor space or access to private gardens compared to detached or semi-detached houses
- Service charges: Most duplex apartments are leasehold properties, often incurring annual management fees for building maintenance and communal services
FAQs
What is the difference between a flat and a duplex?
Flats are usually single-level properties, while duplexes have two levels with an internal staircase. The duplex layout typically creates more space and privacy than a standard flat.
Are duplexes popular?
Duplexes are popular amongst Londoners, especially in new builds and conversions. They can provide more flexible and spacious homes in comparison to single-level flats.
Duplexes vs townhouses (US): What are the differences?
Townhouses in the US are in a row of homes, often sharing walls with their neighbours on both sides. In the UK these are more commonly called terraced houses.
In contrast, US duplex owners or renters live in one of two separate units within a single building, sharing only one wall and usually enjoying more outdoor space.
Final thoughts: What is a duplex flat?
That’s a comprehensive look at what a duplex is – I hope you found this guide helpful. Elsewhere on the Fine Living blog, there are lots of guides you may find useful, including:
To see the latest Fine Living properties, take a look at the portfolio for details on all the latest houses, apartments and any duplexes we have.
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