Process for redevelopment

In September 2019, our Trust was announced as one of twenty one hospitals to receive a share of £100m funding.  This funding allowed us to develop a business case for the redevelopment of the hospital. Since then, we have moved quickly to progress our plans. 

When we design our hospital, we are doing so as part of the National Health Service, as part of the Hillingdon community, including the local authority, CCG, GPs, H4all, Hillingdon Health and Care Partners… and as part of the wider NW London Acute Provider Collaborative and  other acute hospital providers in the area.     

Designing a hospital is not a quick or simple process and there are many elements which must be considered at these early stages. This page takes you through the formal business case process and the steps we take to design a hospital.   

The process

To be able to access the funding which is required to develop the new hospital, we must follow the process set out by HM Treasury and NHS England/Improvement to show that we have considered all options and selected the best option for the redevelopment of the hospital. 

The three stages are:

Business process stages

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Strategic Outline Case (SOC)

The Strategic Outline Case (SOC) sets out why a change is needed, reviews the options and sets out the preferred way forward.

  • The SOC confirms the strategic context of the proposal, makes a robust case for change and uses stakeholder input to develop a proposed way forward

  • Approval of this rests with the Trust board

  • Support is required from the main CCG and ICS who will in turn require that the proposed way forward is aligned to the needs of the wider health and social care system.

  • NHSE/I and DHSC will provide feedback on the SOC, and approve the release of funding required to progress the OBC.

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Outline Business Case (OBC)

The Outline Business Case (OBC) demonstrates that the chosen option is affordable and value for money.

  • The OBC provides the detailed architectural design of the solution, demonstrates value for money and adds detail to how the solution will be delivered, e.g. procurement and commercial approaches.

  • Planning discussions with the local authority occur at this stage.

  • In addition to the SOC requirements of approval from the Trust Board, main CCG and ICS, the OBC requires approval of NHSE/I, as well as sign-off of the procurement documentation by DHSC.

  • Treasury approval may be required at this point.

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Full Business Case (FBC)

The Full Business Case (FBC) is the final stage which provides detail on procurement and delivery.

  • The Full Business Case adds further detail to how the solution will be managed and delivered, including running the necessary procurement process(es).

  • At the conclusion of this, contracts can be signed and the project transitions into delivery

  • Again Trust board approval is needed, and NHSE/I and DHSC approval is required for the signing of contracts.

  • Treasury approval is required to release the required funding.

Designing the hospital

The design of our hospital is driven by what is best for patient care and ensuring the right flow around the hospital. 

Design process

The designs start with our Clinical Services Strategy which talks about what Hillingdon Hospital, as an acute hospital, needs to provide to meet future population needs and how this is best achieved. We then look at a number of factors that enable us to decide the right size of the future hospital. 

Our clinical cabinet and clinical and operational working groups look at what their area needs to look like in the future, considering questions like;

  • How will they deliver care?
  • What equipment will they need?  
  • How can they take advantage of digital development?  

Once they have agreed the core principles, they work with specialist health planners to look at how the hospital will flow and which departments need to be near each other. This allows the architects to begin their work, placing the departments and looking at the overall shape of the building. The plan then goes back and forth between the architects, planners and clinicians to address the following questions: 

  • Does it work?  
  • Will it deliver for our patients?  
  • Does it respond to the feedback from our community and staff to help shape the plans?

Right sizing the hospital

Demand projections

To understand how many people are likely to need to use the hospital, we look at data from a number of places. 

  • Baseline activity data for calendar year 2019 (to avoid the impact of covid)
  • Apply ONS population projections by age cohort to reflect demographic change (April 2020 issue)
  • Other growth factors including an uplift for maternity to reflect local strategy.   

Capacity calculations

  • Apply assumptions to activity volumes to model resource requirements (bed days, theatre hours, clinic hours) 
  • Apply assumptions about efficiencies to be derived from achieving benchmark
  • Apply operations assumptions (sessions per week, utilisation etc) to generate capacity needed


We review our assumptions against other similar schemes and best practice guidelines.

  • NHS Model Hospital metrics
  • Experience of other HIP schemes
  • Getting it Right First Time (GIRFT) recommendations 
  • Royal College guidelines where applicable