In 2018, Ryder Architecture published Reinvention for an Exceptional Construction Industry. 1 It called on the whole project team to unite behind a single goal to place the project ahead of each team member’s commercial priorities. At the heart of this is a commitment to integrated design and collaborative project working; breaking down the historic silos of the built environment professions and industry, and embracing and developing digital design technology to provide a synergy from concept to construction. That synergy is fundamental to developing a response to the challenges of delivering the New Hospital Programme (NHP), embracing the potential of Design for Manufacture and Assembly (DfMA) and Modern Methods of Construction (MMC) to bring significant benefits in terms of on-site productivity, quality, environmental and social impact, and whole-life cost
Building on our successful collaboration on complex hospital projects, and harnessing significant global healthcare experience alongside trusted engineering partners, WSP and Hoare Lea, we developed and jointly published in 2021 the research paper, Intelligent Hospital Design Principles, 2 to respond to the key drivers of the NHP.
Pioneering use of MMC on Stoke hospital project
Ryder and WSP were part of the design team working alongside Laing O’Rourke for Royal Stoke University Hospital that pioneered the extensive use of MMC technologies on major hospital projects in the early 2000s. We built on our knowledge and experience in the development of the design for the multi-award-winning Dumfries and Galloway Royal Infirmary (DGRI). On the DGRI project, developed with Laing O’Rourke, the application of digital design enabled a direct workflow from design to manufacture, testing and optimising alternative scenarios, and coordinating components. Our digital design models were used directly as a base for supply chain fabrication information, and to inform the programme of component installation, reducing time and risk. The hospital was completed six months ahead of contract programme, with associated cost benefits and reductions to community disruption and carbon emissions.
Evolution of the envelope design
DGRI was a great success, but there were lessons to learn. For example, as part of the evolution of the envelope design, the number of external panel types grew from a small number of generics, to a large number of bespoke panels with varying structural thickness levels and connection details. To improve standardisation and optimise sequencing where construction progress was not reliant on a number of bespoke panels, we have developed the modularity of the external design for subsequent projects at Whipps Cross Hospital in Leytonstone, and at Leighton Hospital in Crewe. All three projects incorporate an external panel design that enables window modules to be installed off site, with suitable minimum chord widths below and to the side of windows. At Whipps Cross, feature piers and fins are designed as separate panels to avoid increasing the number of panels through handing, and to design out asymmetric loading of panels.
These design considerations will optimise the lifting operations and improve programme efficiency, learning directly from DGRI, recognising that if MMC programme and cost benefits are to be realised, particularly on tightly constrained live hospital sites, then crane hook time and just-in-time delivery need to be key design considerations from early concept stage
Struggling to ‘flex’
Traditional bespoke hospital designs can struggle to flex and quickly adapt to change. By developing designs based on a standardised platform approach, underpinned by a dimensional rigour which leaves room for flexibility, and incorporating standardised design components, we can begin to realise the opportunities of pre-manufactured value (PMV), the measure of the extent of offsite construction used on a project. This standardised platform approach can be combined in a number of configurations to meet the bespoke needs and demands of any given project, creating a flexible framework based on the key principles of NZC, MMC, and a digital strategy aligned with the international standard for BIM and information management, ISO 19650
A key challenge for the UK New Hospital Programme is to facilitate the flexibility required to respond to the current and future needs of individual projects, while adhering to the demand for limited scope for variation. Rather than setting a definitive standard grid and fixed templates for clinical settings, we have developed a series of design principles that can be implemented to inform, but not limit, projects, studying how typical rooms and spaces can be stacked to respond to particular sites, massing, scale, land take, typology, and brief constraints. This approach builds on our knowledge of standardised platforms from other projects, our contribution to the P22 repeatable room programme, our lean design development of an HBN 15-01 exemplar Emergency Department, and our collective expertise in the delivery of MMC for healthcare to inform current design proposals for a number of major hospitals across the UK.
Dumfries and Galloway Royal Infirmary – early supply chain engagement
Dumfries and Galloway Royal Infirmary is an exemplar of offsite and modular construction. The project utilises systems including large-scale prefabricated components and structural elements – from external envelope panels, to pods, to building service installations. The goal was to lead a step change in increased production of the construction process, and quality improvements, plus an associated reduction in costs.
The advanced application of BIM allowed a direct process flow from digital prototyping at design stage through to manufacture. The design team, working directly with the contractor, adopted standardised and prefabricated components and elements of construction to improve product quality, guarantee consistency of performance, enhance efficiency of maintenance, and provide flexibility for future changes and ease of replacement. This was an integral part of the project delivery strategy, and was applied to all aspects of the building – civils, structure, envelope, internals, and services.
Façade system
The façade system is a series of precast load-bearing insulated panels that are manufactured off site using Laing O’Rourke’s DfMA principles. The use of offsite-manufactured wall panels, complete with insulation and window installation, facilitates safer, cleaner, and more efficient construction techniques, which minimise disruption, guarantee quality and cost, and save time by reducing the overall construction period. The principles of DfMA are integrated into project workflows from initial concept design through use of BIM-enabled parametric modelling. BIM applications assisted in the development and use of standardised components for structure and building envelope using 3D geometry and property and performance data embedded in the models.
DfMA components were coordinated with other disciplines through early clash detection, with design models directly used as a base for fabrication information, reducing time and risk. BIM models were used for 4D construction simulation planning to inform and communicate installation of components on site. This enabled accurate tracking of required fabrication times, proposed installation dates, just-in-time delivery to site, and communication with other trades. Offsite manufacturing decreased resource-related pressures from the project, and also skilled new entrants to the industry in Modern Methods of Construction.
Cast with individual textures and motifs
A combination of sophisticated technology, and the application of craftsmanship in the bespoke offsite manufacturing process, allowed the façade panels to be cast with a range of individual textures and motifs. We embraced this opportunity to enrich the design of the external elevations and integrate the external materiality with an overarching woodland campus concept. The detail design of the façade system was developed with an understanding of the climatic factors that will affect the building in its location; particularly the relatively high levels of rainfall experienced there.
External windows and doors were factory fitted into the panels, ensuring that all interfaces are correctly aligned, tolerances achieved, fixings appropriately located, and sealants professionally and neatly applied. A factory hose test ensured the watertightness of the window and door installation before the panels left for site. The detail of integrating external windows into the cladding was tested on prototype panels for the project before large-scale fabrication was undertaken. This unique approach – exploiting the opportunities and advantages of premanufacture – enabled the team to commit to delivering the new hospital six months earlier than the date specified in the client’s programme. As well as providing significant savings and value-formoney benefits, this enabled the hospital board to plan its commissioning, decant, and occupation processes, during the late summer period, allowing the hospital to be brought into operation well ahead of winter pressures
Whipps Cross Hospital – developing a flexible approach to MMC
The Whipps Cross Hospital redevelopment is a significant mid-rise new build hospital, and part of Cohort 3 of the NHP. Alongside design partners, WSP and Hoare Lea, we have developed a clear approach to maximise the value that MMC can bring to healthcare environments of the future.
In response to the physical constraints of the site footprint, Whipps Cross requires vertical stacking of departments and functions. This presents challenges in the development of a standard grid that avoids transfer structures between levels. The grid dimensions have been developed to coordinate with both the standard inpatient template of the upper levels, and the constraints of a standard theatre template within the lower technical levels. In addition to the spatial demands of typical rooms and workflows associated with each function, grid dimensions and structural solutions were considered holistically, alongside embodied carbon calculations and cost efficiency.
Central circulation / support hub
Inpatient accommodation is designed as a series of standard ward modules around a central circulation and support hub. This arrangement is informed by a series of typology studies that considered the particular challenges and opportunities of the available site for the new hospital, alongside a response to the aspiration for an exemplar hospital with a special interest in the frail and elderly. The pinwheel design typology of Whipps Cross optimises horizontal travel distances to wards, in response to the frail and elderly patient cohort. It also brings efficiency to staff workflow, allows effective sharing of support space, and provides resilience for separation and isolation
Ward modules are 28 beds, with repetition of a single room module which defined the grid taken through to the lower floors. The bedrooms are clustered into sevens; each half of the ward has a four-bed bay, to maintain balance, with staff bases distributed to provide optimum observation. The layout of the single room and en-suite was tested to ensure that the visibility and observation of the room from the corridor was optimal.
Maximising MMC potential
To drive maximum pre-manufactured value, a number of hospital typologies were assessed for their ability to maximise MMC potential as part of the overall weighted assessment and selection. In addition to optimising workflow and horizontal travel distances, the pinwheel typology was assessed as being able to efficiently accommodate a range of MMC solutions.
A more detailed review was then undertaken to assess the ability of potential MMC approaches to respond to the key criteria, including:
Structural requirements.
Clinical planning.
MEP.
Façade
Finishes
A detailed score-based assessment was used to narrow the options down to the most appropriate for this type and scale of development. Once complete, this provided a framework for decision making, moving through the Outline Business Case (OBC) stage. As we were designing without supply chain engagement due to procurement considerations, key to our strategy at this point was keeping as many MMC options available for as long as possible – consciously not designing out opportunity
Mitigating the risk of supply chain delivery issues When decisions were made, they were tested against which MMC options and associated opportunities might be ruled out, iteratively evaluating the impact of decisions made to optimise our solution. This mitigated the risk of subsequent supply chain delivery issues until further testing can be completed alongside a main contractor’s supply chain. Crucially, floor to floor heights, and the planning envelope for the hospital, were determined to allow for a range of structural solutions when design moves into the Full Business Case (FBC) stage
Poised to capitalise
Our approach was not to close down to a single preferred option at the end of the OBC process. This approach has ensured that the Whipps Cross Hospital redevelopment is poised to capitalise on the growing capacity and expertise of the MMC industry into the FBC stage. Our approach to ensuring that flexibility for MMC is built into the design throughout OBC stages, without early contractor engagement, has been:
Early OBC
Analysis of initial typologies, including suitability to maximise MMC opportunities.
Assessment of all MMC options against key, specific criteria, and selection of the most appropriate options to proceed.
During OBC
Refine the typology assessment to a selection.
Development of a flexible framework based on a standardised platform approach.
Test all decisions against the framework of MMC options to keep as many open as possible for as long as possible.
Finalising OBC
Final selection of selected MMC options.
Keep a number of options viable within the approved outline planning massing envelope until contractor involvement.
National Rehabilitation Centre – Retrofitting an MMC approach
After being brought into the NHP as a Cohort 2 project, the National Rehabilitation Centre (NRC) near Loughborough has a target to achieve 65% PMV (Pre-Manufactured Value). The challenge on this project is that the design concept and principles pre-date adoption into the NHP, and MMC was not a key driver in the development of the original design. The design team has therefore reviewed where the most appropriate locations are to achieve these values
In order to maximise the use of MMC, and in particular offsite construction, a regular façade module has been developed that aligns with the proposed 8.2 m structural grid. The upper floors have a 4.1 m wide façade module with consistent window placement.
A range of external façade typologies were considered and evaluated against criteria including cost, percentage of MMC, embodied carbon content, reaction to fire, airtightness, and speed of construction. The initial approach for the external facade was based on a SFS infill frame with insulation between members, cement particle board, further insulation, and rainscreen cladding. This façade system, however, had an embodied carbon global warming potential of 196 kg CO2 equivalent per m2 GIA. Through further analysis, an alternative proposition utilising non-combustible Structurally Insulated Panels (SIPS), manufactured off site, was developed, which offers enhanced MMC advantages, and has a global warming potential of 125 kg CO2 equivalent per m2 GIA.
Expertise in construction logistics
Integrated Health Projects (IHP), an alliance between Sir Robert McAlpine and Vinci Construction UK, was appointed at the beginning of detailed design, bringing access to supply chain, and expertise in construction logistics, which were fundamental in developing the MMC strategy. A series of detailed design sprints at the outset quickly integrated the IHP team into the project, and enabled the effective input of the supply chain. With this input the use of non-combustible SIPs panels was developed, positioning the panels outside of the post-tensioned concrete frame to allow a faster construction programme than a more traditional construction technique. This enables the building to be weathertight earlier for concurrent works to commence
In addition to applying MMC principles to the façade, the team has developed the MEP design and procurement strategy to allow for the exploitation of offsite prefabrication of repetitive services elements and assemblies. This approach drives productivity and programme improvements during construction.
Summary
To maximise the success of MMC, it is critical to get all decision-makers on board from an early stage, and ensure that key decisions are made at the appropriate milestones. This often requires a shift from a traditional mindset, where a protracted, linear approach to procurement and supply chain engagement and late design freeze are often the norm.
While the façade design of NRC has been able to develop to embrace effective MMC solutions, retrofitting an MMC strategy to a predeveloped design that had detailed planning approval has presented challenges. To realise the full potential of MMC it must be considered from first principles, ideally with the engagement of supply chain partners – as was the case at DGRI – and a shared understanding that some critical decisions need to be made early, whilst allowing room for flexibility. Without the ability to engage supply chain partners, the challenge and underlying approach is that of Whipps Cross – to consciously design in opportunity, and guard against designing MMC opportunity out
Need for collaboration
At the heart of a factory-to-frame approach there must be a commitment to collaborative project working – embracing digital technology to move seamlessly from concept to construction, reducing risk, and optimising cost and programme. A collaborative, workshop approach will help define a clear strategy, while taking the whole team on that journey
A standardised platform approach will enable the delivery of better care, a better experience for patients, and a better environment for staff to provide care in. The approach provides an efficient and functional framework, with flexibility and adaptability to respond to changing healthcare needs in the future. The standardised platform must integrate key structural and building services engineering principles to design in flexibility for a range of MMC delivery options.
To deliver on NZC targets, the MMC strategy needs to dovetail with both the overarching NZC strategy and the detail that supports that. A commitment to NZC must inform the design from first principles. In analysing initial typologies we need to consider the form factor in terms of environmental performance, and also in terms of complexity and suitability to support an effective MMC strategy. This combined approach to NZC and MMC needs to continue as the design develops, for example in an assessment of embodied carbon in structural frame options, and the optimisation of grid dimensions. Early resolution of the design and its pre-manufactured components and assemblies can offer opportunities for early accurate prediction of embodied carbon by establishing the provenance of materials as part of the offsite manufacturing process
Opportunities and barriers
In the context of a complex largescale hospital build programme, there are significant opportunities, but also significant challenges and barriers. As designers and integrated project teams we need to collaborate to provide support in navigating these challenges to ensure that we maximise the value that MMC will bring to the individual projects, as well as achieving the long-term government ambitions to create a mature, robust, and highly efficient, MMC sector to serve healthcare and wider infrastructure investment.
References
1 Reinvention for an Exceptional Construction Industry. Ryder Architecture, June 2018. https://tinyurl.com/4xmkuba5
2 Intelligent Hospital Design Principles. Hoare Lee, WSP, bimacademy, Ryder Architecture, Barts Health NHS Trust, June 2021. https://tinyurl.com/muyh6cyp
Paul Bell
Paul Bell, a Partner at Ryder Architecture, completed his architectural education at the Mackintosh School of Architecture, Glasgow, in 1992, and has led several high-profile urban design, health, and infrastructure projects. In 2006 he established Ryder’s Glasgow office, and led the early development of the Hong Kong office. Prior to joining Ryder, he worked with Terry Farrell for 11 years in London and Hong Kong. Paul has spoken around the world on sustainable healthcare design and blurring the boundaries of healthcare to address health equity. He brings his expertise of leading integrated project teams to successfully deliver major healthcare projects. His passion for delivering design of the highest quality is recognised by excellent client testimonials and project award nominations.