Construction expertise

Complex project wins a national award

The complexities of this project are not visible in the end result – which is exactly the way it should be on any development. But, it does demonstrate well the technical abilities of the Kisiel team.

Having undertaken a full refurbishment of the Main House a couple of years ago, we returned to complete the more complex second phase of the project.

The project brief

The clear vision to increase the usable space included the:

  • refurbishment of the two storey Coach House,
  • addition of a ground floor wrap extension to link the Main House to the Coach House,
  • creation of a basement level beneath the garden for additional usable space,
  • and the installation of a lift shaft and an elevator for access from the Ground floor to the basement level.


The plot had adjacent properties on three sides: the Main property to the front, the two storey Coach House to the right and a neighbouring three storey property to the left.

We had a very narrow access, through from the front of the property to the garden area at the rear, for the delivery of the machinery and materials.

Basement excavation

A 1,400 square foot basement needed to be excavated under the garden to provide additional living and working space. 

To avoid excessive noise disruption to the neighbours, continuous flight auger (CFA) reinforced concrete pile were used. These provided lateral support and retained the surrounding sub-soils.

Following piling, additional temporary Steel bracing was installed to provide further support during the excavation of the basement levels. The capping beam was then cast – including cantilever section where applicable. The supports were reconfigured to brace the capping beams and the basement structure was then formed

The basement was waterproofed and rooms set up as specified. To complete the job, the garden was replanted on top of the basement. The only clue that the basement is there is where the light is being creatively drawn to the lower level through a light well in the garden.

Other works

The wrap around extension had a green roof established on the flat roof. However, you would not be aware of this as you relaxed in the entertaining space below.

Installing an elevator required the lift shaft to be built to exact measurements with total precision. This avoided issues with the function testing of the elevator, giving a smooth ride to the basement level.

Our team undertook a quality refurbishment of the Coach House, converting it to a stunning additional bedroom accommodation.

And finally…

Overlooking the garden in Clapham, the Kisiel team have created a large entertaining and relaxing space.

Kisiel did a great job on a challenging project in Clapham. The project included a full internal refurbishment, rewiring, plumbing etc,. a new contemporary extension to the garden and a basement under the garden linked to the main house. This complex and demanding project was handled very well by Lukasz and his team and the client is very happy.

Architect at

We are always delighted to work with a company that has the same professional ethos as ourselves. The most important aspect to us is that the client is very happy. It was a pleasure to work with you once again and we look forward to the next project!