Project type
Aerial sketchy renders of a property in London doubled in size thanks to a symetrical side extension
Photo-realistic renders of the existing property of a modest size on two floors and a lot of garden space to its side
Photo-realistic renders of the proposal of the side extension to showcase to the council how fitting it sits within it's streetscape
Off-white study and reading nook area with hints of olive greens and yellow to accent the neutral tones
Pale yellow and white day bed with plush yellow, white and baby blue pillows encased by decorative wall storage
Modern and sleek bathroom sink with grey and white marble, long rectangular glossy tiles and warm natural wood cabinets
Existing ground floor layout of the property
Symmetrical side extension doubling the property in size and space for a growing family home in Bexley, London
Existing first floor layout which only permitted for two bedrooms and one bathroom
Architectural proposal drawings to extend from a two bedroom property into two bedrooms with an en-suite bathroom and one luxurious and spacious master bedroom with an en-suite bathroom with double sinks and double toilets

A surprising two-storey extension that more than doubles the size of the original house


Campion Cottage DA5

Plot Type


Project Type



An increase of 93 sqm

Services by Urbanist Architecture

RIBA 0-3


Our clients wanted to design and create a spacious, luxurious home for their large family. They needed our services to secure planning permission for building a (very) large house extension. Our extension design concept focused on high-end interior design incorporating clean lines and sleek surfaces in the bedrooms and extensive living, leisure and entertainment areas.

The original detached house had only two bedrooms and was too cramped for the family. As the house is on a corner plot with a huge amount of external space, their intention was to maximise the potential and double their property size. However, what seems like a good idea to a homeowner is sometimes the last thing a planning officer wants to see.

In this case, councils often prize the openness of big corner plots, considering that a key feature of the street scene and the feel of a neighbourhood, especially in suburban areas like this one. So convincing the planners that a substantial extension here would be a good thing was never going to be easy.

Before & After

Existing ground floor layout of the property


The particular shape of the house offered a radical option – rather than add a large but conventional extension that might look like it was overwhelming the original building, we decided to do something different.

From the front, we would be mirroring the design of what was there at the moment, creating something that was pleasingly symmetrical. What would happen on the inside would be a complete transformation, but on the outside, it would look completely at home in the neighbourhood. That is how we were able to convince the planning officers that a two-storey extension design wouldn’t be over-development or have a detrimental effect on the street scene and general character of the area.

The stylish design concept helped our clients secure planning permission for their extension and doubled the size of their property, going from a standard 79sqm to a gigantic 172sqm for family leisure activities. The bedrooms were fully renovated and equipped with en-suite bathrooms, a jacuzzi and walk-in wardrobes, ideal for contemporary lifestyles.

Not only did we help them add an impressive two-storey extension to the house, we also designed an indoor swimming pool with stunning open-plan interiors. We gained approval for an outbuilding with a swimming pool and gym and added an extra 38sqm to the space, on top of the almost 100sqm internal area of the property. This outstanding large house extension is a perfect example of what can be achieved with the very best of London’s architectural expertise and innovative design.

Symmetrical large side extension doubling the size from the original property

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