Making Modular Prefabulous – John Colvin talks offsite volumetric construction

As modular volumetric construction comes of age in the UK, John Colvin, Head of Hotels and Leisure, talks about our experience of using the process on large scale projects on two recently completed Hampton by Hilton hotels.

hampton by hilton bristol airport hotel

The modular tipping point?

Hovering for a long time on the margins of acceptance, off-site construction has finally entered the mainstream. With the rising cost of traditional building materials, skills shortages and improving technology, modular is now the smart choice for clients of building types that yield returns from day one.

In hotels, for example, the benefits of speed on site are self-evident. The sooner the doors open, the sooner the bookings can start rolling in.

With the majority of such buildings constructed and finished in the factory, modular construction can reduce the time on site by up to 30%. On top of that, modular avoids on site delays, assures quality, minimizes health and safety risks, and it is said, requires up to 70% fewer labourers on site. For hotel clients prioritising no-nonsense quality, certainty and speed to reduce development risk, it is a no brainer.

bristol airport hotel

Hampton by Hilton Bristol Airport Hotel

Indeed, the Hilton brand has wholly endorsed the strategy for their focused service brands, to the extent of commissioning its own branded promotional Lego model, replete with crane and lorry to swing the modules into place.

Volumetric modular construction sounds as straightforward as building Lego. Order some factory-finished standard pods, stack’em up, plug’em in, and Bob’s your uncle.

Needless to say, the reality brings a few more challenges. There are always non-standard considerations, especially at the interfaces: the shape of the site, the levels, the elevations, the bespoke spaces for context-specific circumstances, and, of course, the whole-building strategies such as fire safety, thermal control, noise attenuation and energy efficiency.

Detail of the @hamptonbyhilton Bristol Airport. Those are actually shipping containers 😮

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Just as important are the numerous local regulatory constraints, including planning approvals, building regulations, brand and stakeholder requirements. Overall dimensions, finishes and performance expectations are set very early in the process, and it takes acute design skills and coordinating logistical competence to get it right.

Hampton by Hilton, Bristol Airport

Stride Treglown’s first hotel opened for business in Bristol in February 2017, and has been doing a roaring trade ever since. Conceived as part of Bristol Airport’s confident plans to dramatically expand their passenger capacity, the noisy site came with permission for an H-plan 251-bed hotel, with a first phase of 201 beds.

Chinese volumetric module manufacturer CIMC-MBS bought and developed the site both as a commercial venture but also to showcase its product in the UK. Following a successful planning approval for Bristol Airport Limited, we were commissioned by CIMC to carry out architecture, hard landscaping and BREEAM services.

The completed building features two parallel wings of accommodation joined in the middle by a bespoke three-storey glazed link. The whole building has the built-in capacity to easily add an extra 50 modular bedrooms as demand grows. Indeed, the largely bespoke ground floor facilities, which include the lobby, meeting rooms, lounges, open-plan bar, restaurant and fitness suite – are especially generous in size in anticipation of that growth.

At the time, CIMC had no off-the-shelf solution for secondary glazing, a critical feature in the context of a noisy airport. Collaborating closely with CIMC’s engineers, we designed an effective, compliant solution that not only survived the container ship journey from China but meant that the module interiors could be left untouched during the build.

Hotel room vibes. ❤ #bristol #england #hotel #hampton #hilton

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The cladding not only had to remain fit for purpose and meet CIMC’s statutory Planning obligations, it also had to work with the modular system’s loading limits and not compromise the integrity of its fabric. A lightweight aluminium composite panel solution works, saving time and money for the client.

Hampton by Hilton, London Docklands

Stride Treglown’s second CIMC-MBS 209-bed hotel project was conceived to serve delegates at the nearby ExCel international exhibition and convention centre. It opened for business in London Docklands in April 2017.

Partly on CIMC’s enthusiastic recommendation, the developer appointed Stride Treglown to manage the alterations to the planning approvals, design the non-standard architecture and interiors, undertake the BREEAM services, and coordinate the design.

The Planning picture was complicated. The consent included two other building on site as well as the Hampton by Hilton site, and so applications for critical amendments had to encompass all three buildings and not just the hotel.

Maccreanor Lavington, who secured the original consent were retained to monitor external appearance matters as stipulated in the Planning approval. Stride Treglown managed these extra project constraints with common-sense solutions to deliver a final product the client is delighted with.

Two moves in particular added value for the client and improved the hotel experience for guests. First, Stride Treglown secured consent to replace the café with a 100-seater restaurant, cleverly reorganising the ground floor spaces within the approved building envelope. Second, they also secured a change of use consent for unwanted office space, replacing it with bespoke extra bedrooms.

The future

The key lessons from Stride Treglown’s recent experience are to do with sequencing, design coordination, and applied research. There’s room for on-site additions, but they must be curtailed to maintain modular’s primary advantages, which are speed and quality.

Instead, its constraints must be taken as the grit in the oyster. We have far-reaching ambitions to explore the technology’s full potential.

“Just like with any unconventional construction material, whether it’s straw or volumetric modules, there’s huge scope for innovation and inspiration in pushing it to its limits.”

Theoretically the basic module could be rotated in any plane to create new forms and user excitement, the system’s very essence is its ease of demounting. This opens up enticing vistas of end-of-life reuse, significantly boosting the concept’s overall sustainability.

Bristol Airport Hampton by Hilton – ‘Highly Commended’ runner up for Best Commercial Project of the year – Offsite Awards 2017.

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