- Project plans
- Project activities
- Legislation and standards
- Industry context
Last edited 15 Dec 2014
North Middlesex University Hospital Maternity Unit
Kevin Jones, Director of Business Development at the Portakabin Group looks at the UK’s largest modular building project to be built in the health sector and how such a complex building was delivered on time and to such a challenging programme.
The Women and Children’s Centre is part of an £80 million modernisation and expansion programme – the biggest transformation in the history of the hospital. The new maternity unit is said to be ‘the envy of NHS organisations across the country’.
 A building to accommodate a rapid increase in maternity patients
North Middlesex University Hospital was established in 1991 and serves a diverse population of around 260,000 people. The centre was built to accommodate the increase in maternity patients and around 2,000 additional births in North Middlesex. The project forms part of a major reorganisation of hospital services in the boroughs of Barnet, Enfield and Haringey. The deadline for completion of the project was time critical.
 A challenging deadline for completion
Given the extremely challenging timescale for the project, the Trust looked at more innovative methods of construction – and the decision was taken to use an off-site solution to reduce the build programme by around seven months. This would ensure the new facilities became operational in line with the Trust’s clinical strategy and prior to seasonal winter pressures. The approach would also radically reduce disruption to patient care on an extremely busy hospital site.
 Fast-track building envelope for earlier fitting out
152 steel-framed Yorkon modules up to 18m long and weighing up to 18.5 tonnes were craned into position in just 28 days creating a full building envelope that allowed fitting out to be progressed at an earlier stage than on-site construction methods. A 500-tonne crane was used for this operation which took place within the hospital grounds and in close proximity to existing facilities that remained in use throughout.
 A design to reflect the existing hospital architecture
The external appearance of the scheme reflects the design of the existing buildings on the hospital site and features rendered façades, ribbon glazing around the perimeter of the first floor, a large atrium entrance spanning two storeys with light wells up to 15m long providing further natural daylight inside. There is full-height glazing to the stair towers on each of the two wings and large projecting window bays provide a visual contrast to the rendered finish across the building envelope.
 Technical Advancements in Off-site Construction
The North Middlesex project is the largest application to date of the latest Yorkon off-site building solution, which gives architects, contractors and clients the widest range of building modules currently available from any off-site manufacturer in the UK. It also offers the design flexibility to meet almost any building footprint. It has literally thousands of configurations and permutations to realise the full potential of off-site construction as a much faster and more efficient alternative to site-based building methods but with no compromise on design, aesthetics or layout. Technical advancements include:
- Columns that are no longer visible either internally or externally, for a seamless façade that can be specified with or without cladding.
- Module lengths from 6m to 18.75m that give even greater flexibility and the option of using larger but fewer modules to reduce cranage, transport costs and site works.
- Two module width options of 3m and 3.75m; three height options for single-storey buildings, and seven different heights for ground and intermediate floors on multi-storey schemes to facilitate linking to existing traditionally-constructed buildings.
- Connections between modules that are made from inside the building – which is more efficient, quicker and safer on site.
- A building structure that is manufactured to engineering rather than construction tolerances for even greater accuracy and better build quality.
- A wall construction which offers improved insulation and acoustic performance, and an even wider choice of window and fenestration options.
- A new insulation production system to further improve quality and consistency.
- A 30-year structural warranty for even greater peace of mind.
- A wider palette of colours for the steel envelope which has been expanded from 20 to 55, giving architects genuine creative freedom without having to specify secondary cladding.
The building at North Middlesex University Hospital was handed over on time just 10 months after Portakabin was instructed to proceed and babies were arriving within hours of completion. The use of an off-site solution for the project generated a programme saving of around 28 weeks, to the benefit of patient care.
The unit’s brand new birthing centre includes eight home-from-birth rooms, four with birthing pools and all with double beds to make partners feel welcome and encourage them to share the experience of their child’s birth more fully. The neonatal unit has 18 cots for newborn babies who require special care, with three mother and baby rooms and the capacity for 10 further cots. The labour ward includes a 17-bed delivery suite, a high-dependency bay and two operating theatres.
The building also accommodates a consultant-led delivery unit with additional high-dependency beds, two obstetrics theatres, triage centre, and a women’s outpatient department with 26 consulting rooms. A roof top plant room is located on the second floor.
The early engagement of the Portakabin Group was hugely beneficial on this project. It allowed the design to be developed in line with the Yorkon modular grid so that off-site working could be maximised, reducing disruption on site and contributing to completion on programme.
It is important to allow a degree of flexibility in space planning. Internal layouts should not be fixed without considering whether a room could bridge across a module. Containing rooms within a module will maximise fitting out off site, which is more cost efficient and faster.
Any client has to be realistic about programme and clearly late design changes are always possible but they have time and cost implications. If the opening date is critical, design changes should be very minimal or allowed for in the programme.
Close co-ordination and integration between the main contractor and the off-site specialist should be in place throughout both the design and delivery phases. The Portakabin Group had previously worked with Kier Construction on another Procure21 project. This £10 million subcontract provided a new children’s department, elective care centre and surgical ward at Colchester General Hospital and used a Yorkon off-site solution to reduce the programme to just 10 months on site.
Where completion dates are time critical, contracts and instructions should be issued on time or this will contribute to front end delays which can be very difficult to recover from. Early design freeze on layout is also very important.
Lastly, it was found that the Procure21+ NEC form of contract promotes a structured and collaborative method of working. It is a good project management template but only works if all parties adhere closely to it and have a good understanding – which also applies to the downstream supply chain.
 Minimising the Building’s Carbon Footprint
The project achieved a BREEAM ‘excellent’ rating and has a number of sustainability features including a green roof with a variety of meadow flowers to part of the first floor, photovoltaic panels above the plant room, and an energy-efficient combined heat and power system.
Catherine Barns, Senior Project Manager at North Middlesex University Hospital NHS Trust, said, “Given the extremely challenging timescale for this project, we needed to look at more innovative methods of procurement and construction. By using an off-site approach we were able to deliver a fantastic building of this scale, on time and in an unreal timescale, which was a tremendous achievement for the Trust, Kier and Portakabin."
“The partnership between the users, Kier and Portakabin worked very well, and in particular the flexibility shown by Portakabin in the face of changing healthcare requirements. Other health professionals from both the UK and internationally who have visited the building since its completion have been very impressed by our new facilities; staff love its functionality and efficiency, and patients have likened it to a hotel!”
An estimated 5,500 babies will be born at the unit each year – which equates to an average of one baby every 90 minutes. The hospital now triages higher risk pregnancies, and 94 per cent of mums who give birth at the hospital would recommend it to friends and family.
--The Portakabin Group 14:52, 1 December 2014 (UTC)
 Find out more
 Related articles on Designing Buildings Wiki
- Kit house.
- Live event production.
- Modular buildings
- Modular Solutions to Place Planning Issues
- Off-site prefabrication of buildings: A guide to connection choices.
- Pushing the Boundaries of Off-site Construction in the Healthcare Sector
- The history of fabric structures
- The Myths of Modular Construction
Featured articles and news
The admissibility of evidence.
How many can you name? 37 anyone?
CIOB respond to the points-based system.
When is the weather considered 'exceptionally adverse'?
ECA backs call for a rolling programme of rail electrification.
What does 'curtilage' mean and why does it matter?
Our duty to prevent harm and protect each other.
A quality perspective.
If buildings were people, they would be just starting to walk on two legs.
Air filtration and clean air standards.
The Dukes of Normandy and the second world war.