BREEAM Outstanding certification places Sidara’s ultra-sustainable 150 Holborn in top five buildings in the UK, and second in London

Sidara’s London showcase office at 150 Holborn has been awarded the prestigious accolade of BREEAM Outstanding. The landmark office building in the heart of the city was awarded a score of 97.2 percent, placing it inside the top five of all comparable buildings nationwide – and second in London.

Having opened its doors in 2023, 150 Holborn houses a number of Sidara brands and was specifically created to exemplify everything the group stands for in terms of sustainable design, technological advancement and creating spaces for that allow people to thrive.

Through a multitude of integrated design interventions – both large and small – the building is intended to be a true beacon of sustainability.

It now officially functions as a ‘net carbon positive’. This means that with 100% renewable energy tariffs alongside our own solar panels on the roof, the building removes more carbon dioxide from the atmosphere than it emits, thereby creating a positive environmental impact.

Sustainable design features include

100% of the building’s energy comes from renewable sources, and PV panels on the building’s roof also provide up to 3.7% percent of its usage.

A ‘blue roof’ harvests rainwater that is then used throughout the building. This prevents stormwater overloading local sewer systems by reducing run off by up to 50%.

‘Grey water’ from sinks and dishwashers is collected, treated and used for flushing toilets to dramatically minimize potable water consumption.

All plants on the building’s roof terrace are especially-selected native species that are able to thrive on rainwater alone, preventing the need for irrigation.

A bee-friendly planting strategy on the roof terrace was developed in collaboration with Camden Beeline, ensuring the right type of flora is available for local bees to thrive.

Procurement decisions all had sustainability front and center, including all timber, steel and glass, as well as all equipment being chosen for energy efficiency.

150 Holborn is more than just an exemplar of sustainable design and construction, it is also one of London’s smartest buildings, having achieved both WiredScore and SmartScore Platinum certifications. It features state-of-the-art technology that monitors occupant activity and automatically responds through changing the likes of light and heating to conserve energy and to make for a more pleasant environment.


Dan Horner, Managing Director of Sidara UK, commented: “This is a monumental achievement for our business and is a living demonstration of our firms’ commitment to using design and breakthrough technologies to protect our planet.

Sidara is the proud owner, designer, operator and occupier of what is now officially one the UK’s most sustainable and smartest buildings. This building is a statement of our collective capabilities in the heart of London embodying not just our business, but also the way we advise our clients when it comes to the design and construction of a better, more sustainable built environment.”