
King’s Cross Roadmap to Net Zero and Decarbonisation
London, UK
Project details
Client
King’s Cross Central Limited Partnership/Metropolitan King’s Cross Ltd.
Duration
2023
ý provided by ý
Advisory, Energy consulting, Sustainability, Sustainability and energy transition advisory
ý played a key role in helping one of London’s largest redevelopments to begin its journey to a decarbonised future.
In response to the Climate Emergency, many organisations and commercial developments across the UK are looking to define their net zero carbon (NZC) pathways. To meet this challenge the World Green Building Council (WGBC) launched the global Advancing Net Zero Campaign, which has set targets for all existing buildings to be net zero carbon in operation by 2050 and all new buildings to meet this standard by 2030.
King’s Cross comprises a mixture of office, retail and residential buildings built between 2013-2024, around the area of King’s Cross Railway Station. King’s Cross Central Limited Partnership (KCCLP), the consortium developing the quarter, has signed the WGBC net zero carbon buildings commitment and has recently committed to achieving NZC by 2035.
KCCLP engaged ý’s sustainability and energy experts to support it in developing a robust definition of net zero carbon, to set out the decarbonisation pathway to achieve this across the whole campus and to develop the engineering designs and contractor procurement to deliver this in practice.
Challenge
The roadmap aims to identify the key retrofit measures necessary for the buildings at King’s Cross to reduce energy consumption and carbon emissions and ultimately achieve net zero carbon status. Delivering this required detailed analysis of current infrastructure and systems, as well as close collaboration with Related Argent the asset and development manager, which has control over the operation and maintenance of centralised building services plant, as well as Metropolitan Kings Cross Ltd who own and operate the district heating and cooling systems and central energy centre.
Wider stakeholder engagement was also required to support the client in identifying and communicating the operational and behavioural changes needed by tenants to ensure net zero carbon could be successfully achieved at a whole building level across the site.
The challenges around reducing energy consumption have evolved considerably because of the changing nature of how employees use office spaces. This is especially true for the application of benchmarking or forecasting future energy and carbon performance when considering more variable, and generally lower, utilisation across the ‘typical’ working week.
Although challenging, this has also potentially created a significant opportunity for lowering the operational energy and carbon of offices through implementing measures such dynamic energy analytics and demand control ventilation.

Solution
A robust NZC definition and methodology for the development was created based on the UKGBC’s framework and aligned to ‘Paris Proof’ 1.5C carbon reduction targets. The definition relies on buildings achieving a bespoke energy use intensity (EUI) target. This is intended to ensure the buildings are significantly reducing their energy demand as well as carbon emissions. These targets were developed based on UKGBC and CRREM and are bespoke for each building’s operational characteristics and baseline performance.
At the outset, we conducted a NZC policy review, which included a wider examination of market trends. We then conducted a series of site decarbonisation audits to assess the potential for demand reduction and deep retrofit measures – ranging from HVAC setpoint alterations and lighting upgrades to technology changes such as “free cooling” chillers and exhaust air heat pump air handling units (AHUs). The assessment of these measures was underpinned by detailed half-hourly energy submetering analysis, and benchmarking the current performance of assets.
We developed a range of implementation scenarios consisting of different packages of measures, from the most aggressive and ambitious, to the more cost-effective and pragmatic. Where possible, all suggested interventions would be aligned with the expiration of the expected lifecycle of the current plant, to avoid waste and embodied carbon emissions as well as mitigating against unnecessary capital costs. Our teams worked closely with the client to develop realistic and achievable rollout programmes for the recommended measures.
We analysed numerous generation, distribution and customer-side interventions through a semi-quantitative assessment to arrive at a shortlist of technologies for further techno-economic assessment. Site surveys and a review of existing system design, performance and metered data was used to develop strategies for the replacement and integration of heating and cooling assets, coupled with customer-side demand and temperature education strategies. We developed a decarbonisation road map based on preferred technologies, supported through client workshops.

The buildings at the King’s Cross development do not have individual gas-fired boilers and instead use a district heat and cooling network. This currently relies on gas-fired combined heat and power (CHP) units and boilers for heat generation. Cooling for the site is via water-cooled chillers, packaged air-cooled chillers and an absorption chiller.
The net zero pathway also identified that the largest amount of carbon savings came from switching away from using natural gas in the energy centre. Our energy system specialists reviewed the existing plant operational data and asset condition and developed a long-list to short-list of suitable technologies. This was then combined with the energy saving measures to develop an hourly model of the system operation. Using our bespoke techno-economic model we were able to identify the optimal estate wide pathway to net-zero.
The first step on the pathway was the design of a 2MW heat recovery heat pump (HRHP) integrated within the centralised district cooling system located within a highly constrained energy centre building adjacent to the main Network Rail lines into St. Pancras Station. We developed a RIBA 3 design and set of employer’s requirements to procure a delivery contractor for this first package.
We also delivered the design and integration of an innovative ground and air source heat pump system (4MW) that will supplement the initial HRHP heat pump operation. This involved close collaboration with ground energy and infrastructure specialists to ensure coordination within the constraints of the site. The final step of the pathway will be to replace the peak load and back-up gas boilers with electric boilers. To facilitate this, we are taking part in an award-winning innovation project called ‘Heatropolis’ with Metropolitan and UK Power Networks to use energy storage and demand management techniques to limit the burden that this places on London’s electrical grid.

Value
The pathways developed provide credible and executable solutions for decarbonising the site based on currently available and established technologies. They set out a clear set of decarbonisation measures and demonstrate the energy and carbon impact of implementing these as well as the capital cost investment required for delivery.
Whole lifecycle cost analysis was undertaken for each building’s pathway and the results were summarised into individual building Action Plans showing the roadmap and the key short, medium and long-term actions required. This resulted in the estimated capital costs for each building for each year – clearly showing the additional net zero carbon costs that the client would need to invest above their current lifecycle cost plans to deliver net zero carbon across the portfolio.
The adaptive reuse of the area’s district heating and cooling network is critical to the successful decarbonisation of King’s Cross, with the largest carbon savings identified as switching away from using natural gas in the energy centre. In 2025, work began on planning the replacement of the current CHP system with a new heat pump-based system. The heat recovery heat pump (HRHP) and innovative ground and air source heat pump system will deliver key operational carbon savings for years to come.
ý will continue to act as trusted advisors for Related Argent, providing advice and support to help deliver the strategy across the estate, including the execution of project design such as the energy centre decarbonisation. The outputs of the study are also being used to help inform an ambitious but achievable target year for a development-wide net zero carbon commitment.
