Co-ordinated assembly

After the architectural oppressiveness of the Scottish Parliament building with its small, caged windows and solid concrete walls, the latest governmental offering, the new National Assembly for Wales has a refreshingly inviting feel.

Sweeping up from Cardiff Bay in a mass of slate, the three-storey structure has unquestionably met the client’s desire for a landmark building. The striking overhanging roof draws you into the building under waves of cedar cladding through the seeming vastness of the double-level public circulation space. Full height glazing surrounding this open-plan area adds a sense of transparency, suggesting the sense of open government the Assembly wants to portray.

Underneath this glazed structure the main debating chamber and inner workings of the Assembly are securely encased within a concrete ‘box’, which is to all extents and purposes underground. “Security was a big issue on the job and the architect has been quite clever here,” comments Jerry Williams, project director for main contractor Taylor Woodrow Construction.

An inventive mix of architecture and engineering has ensured a natural segregation between the Assembly members and public. This provides the secure environment needed, while allowing the voting public to view the debates from above through glass panels – reinforcing the message of openness. “We’re not presenting the old Houses of Parliament, where you get to a set of doors and can’t get any further. Two-thirds of the building is public space; the areas that aren’t are spaces that are viewable by the public,” says Williams.

Structural services

As well as catering for security, the building’s structure plays a major part in the servicing strategy and has helped it achieve the desired BREEAM Excellent rating (see box ‘Sustaining energy use’). “This is probably one of the best examples of an integrated design you’ll see and it has to be because of the environmental nature of the building,” explains Williams.

This integration encompassed the construction team as well as the structure. “Because it’s a very highly specialised project environmentally, a lot of the basic decisions on what was included in the m&e design go right back to the fundamental feasibility of the building,” states Williams. “It’s not a case of design a building and work out how to service it; the environmental conditions of the building and how we achieve them was the primary driver in the early decisions.”

Add to this the fact the architectural mix of exposed concrete and glazed surfaces meant that distribution routes for the m&e services were limited, and it’s clear that getting the construction team members on board early and working together was a necessity.

“If you’re not aware of decisions such as those made to achieve the BREEAM rating, it would be very easy to undo some of the good work by just making the wrong suggestions,” says Williams.

When Taylor Woodrow won the contract to deliver the Richard Rogers Partnership design, the project had endured several years of well-reported political wranglings and a false start on site. This history meant a design was in place and the scope of works already decided when the firm was appointed. Taylor Woodrow was quick to adopt its Strategic Alliance Partnership (SAP) to ensure the success of the scheme and MJN was selected as the m&e contractor.

Williams explains: “MJN got involved not long after Taylor Woodrow. We went through a two-stage tender with the client that established prelims, basic ideas and the design team. MJN had been selected at that point and worked with us solidly through the main tendering period.

“This is probably one of the best examples of an integrated design you’ll see – it has to be because of the environmental nature of the building.”

“One of the questions when we went with the SAP was how much to put into the m&e contractor’s package,” explains Williams. “It was decided that we would go with one large package taking onboard the commissioning of services, controls and even things like the syphonic rainwater system.” This decision was made due to the complexities of the project to improve co-ordination between the different areas of work.

“It does mean that the demands on the m&e contractor are much higher. They must have a team of people who are used to project managing rather than just being specialists in their own fields. Then effectively they become part of our management team,” Williams adds.

MJN’s close involvement at these early stages led to some fundamental changes to allow for the practicalities of the build. One significant area of the contractor’s work was distribution of the services. “Around 60-70% of the services are in a void across the underside of the building,” explains Peter Davies, contracts manager for MJN Colston.

MJN’s influence saw this substantially increase in size. “If we’d followed the consultant’s advice I don’t think we’d have got the services in,” states Williams. “That’s no discredit to the consultant, it’s just getting to that next level of detail.” The detailed design of the m&e distribution had to be completed prior to the casting of the concrete as many of the routes were cast into the structure to meet the architectural desires for clean walls (see ‘A sequenced solution’). “The integration with the fabric of the building has been a big factor all the way through,” stresses Davies. “It involved a lot of interfaces with other trade packages. Things that would have been a minor challenge on a conventionally designed project, have presented big challenges here because decisions had to be made so early in the process.”

Making decisions

There have been few design changes on the project, but this did mean the client had to be sure what it wanted right from the start. If distribution routes had to be cast with the first concrete pours, the contractors had to know where power etc would be needed. “We discussed that with the client at tender stage and set some fairly aggressive targets in terms of issuing that information to us,” says Williams. “The building does have flexibility built into it, but in order to get a proper integrated design you must have all the parameters up front.”

MJN continued the SAP through its supply chain to ensure a thorough co-ordination of the design. Davies explains: “It wasn’t a case that we got prices from x amount of subcontractors – we selected subcontractors from the start and they worked with us to develop the design, so they’ve had the same input as us.”

Both Davies and Williams report positively on the outcome of the management approach used on the project. “One of the main benefits of the SAP is we concentrate on the job and getting it done rather than spending time throwing letters at each other,” says Davies. “There hasn’t been one contractual letter written for this project.”

While the official opening is set for St David’s Day 2006, construction is now virtually complete and the fit-out is well underway. When Assembly members finally make their way across the link bridges from their base in adjoining Crickhowell House, they are sure to be impressed. If not by low energy conditions keeping them cool, by the exceptional design and materials used throughout – the 100 year life and prerequisite for quality enabling whole life costs to be used to great effect.