Learning to skip

Given these objectives it is easy to see how the building became elevated as an M4I demonstration project. For a start, the project brief was a three-page company mission statement rather than the usual wish list punctuated by inflexible design criteria.

Second, the client was far more interested in appointing a project team which understood the company’s business and sustainability objectives than it was to procure a building at the lowest possible price.

Wessex Water encouraged the professional team – architect Bennetts Associates, services consultant Buro Happold and construction manager Mace – to spend the first few months refining their design solutions before getting anywhere near submitting fees for the job. This flexible approach to procurement also meant everyone had time to get to know each other, which created the right relationships for what was to follow.

And what followed was a public demonstration of the virtues of sustainable engineering and supply-side partnering. When the job became a M4I demonstration project in January 1999, everything the designers and constructors did would be open to public scrutiny.

That scrutiny has focussed on two issues: first, driving out waste from the design and construction process, and second, maximising the efficiency of suppliers’ resources through effective project planning.

Driving out waste

The project team’s attempt to drive out waste began with the design itself and followed through to the site practices. It helped that the core of the Mace team came hotfoot from BA’s Waterside project where Mace had already practised partnering and pre-qualification with product suppliers.

“Pre-qualification was the most important part of this project,” claimed Mace services product manager, Gary Snowsill. “Suppliers saw they were being looked at, they wanted to impress, and they wanted to get on the bid list. That way we got far more out of them.”

That effort translated into off-site prefabrication where possible, the very strict use of control samples of all products to minimise on-site reworking, and environmental training (including pep talks on the Kyoto Protocol).

All m&e packages contained clauses requesting supplies to minimise waste. The luminaire fittings, for example, were delivered in reusable boxes which were taken back by the suppliers for the next delivery.

Rather than cut cable on-site, the cabling contractors waited until the plant was installed, took actual measurements, then delivered reels wrapped with cable cut to the right length. Again the cable drums went back for re-use.

Key suppliers were nominated early. “We did this for two reasons,” said Snowsill. “First, it gave Buro Happold more control over the design of the services, and second, the trade contractors inherited a partially completed design.”

Mace hired local contractors whenever possible, which not only improved custody of the project but reduced the petrol consumption associated with travelling to and from site.

Brainstorming workshops were a very successful – if sometimes a little painful – way of challenging established conventions. The team broke down all the options and ranked them in tables showing each option’s importance to the project, the effect on the budget and build programme, and the environmental implications.

“We had to confront our sometimes instinctive assumptions and decisions,” confessed Buro Happold’s Simon Wright, “and it was a fairly rigorous exercise to extract the last few percent of waste.”

More than a few sacred cows were slain in the process. Buro Happold ditched duty and standby pumpsets in favour of a single, variable speed pump and a spare held in the stores. Copper pipe went in favour of plastics for the perimeter heating, and cable tray was omitted for voice and data cables. Instead, these were simply tied and lain directly on the soffits.

Kone won the contract for the lifts largely on the basis that its side-acting motor did away with the need for a lift motor room. This not only removed the need for building materials, but also, since the product comes flat-packed, improved the construction time.

Elsewhere, the construction team looked for the opportunity to use reclaimed materials. Oolitic limestone extracted from the site was either crushed on-site and graded to create 2500 m3 of structural fill, or used to rebuild the site boundary walls.

Crushed concrete railway sleepers contributed 40% of the building’s coarse aggregate needs. While the latter cost an extra £15 000, it reduced the building’s use of quarried aggregate and earned Wessex Water extra points in its BREEAM assessment.

“Last Planner is a flexible tool, and more often than not people play the game”

Gary Snowsill

Despite all this effort it was not possible to eliminate all offcuts from conduit, plasterboard, insulation, and waste from structural materials. To avoid sending all of this to landfill, a waste recycling facility was set up at the east end of the site, adjacent to the building’s goods inward room. This operated as a clearing house and storage area for construction materials.

All suppliers and contractors were coached in ways to reduce waste. So they didn’t forget the lessons, Mace erected signs all round the site exhorting operatives to sort their materials into separate wheelie bins for timber, paper and cardboard, hardcore, glass and metal. These bins were then emptied into skips which were replaced regularly by the recycling contractor, Churngold.

“We had to chivvy contractors quite a lot,” admitted Mace associate director Richard Evans, “but we made it clear to the contractors and site managers that if they didn’t recycle they would lose money.”

Mace is claiming that around 64% of the site waste has been recovered, with the remaining 36% (such as plasterboard) going to landfill – a creditable achievement. But the big question is whether the client’s enthusiasm to protect the environment merely added to its costs.

As of 31 March 2000, the cost of recycling 1758 cubic yards [sic] of site waste stood at a little over £40 000. This compares to the estimated landfill cost of just over £49 000. Even with the waste generated by the fit out still to come, the nominal £9000 saving demonstrates that the economics are easily in favour of recycling.

Project implementation

In developing the sustainability angle of the project, the client and construction team recognised the need for very structured planning of the build process. The Mace team had used the Last Planner technique at BA Waterside and at Heathrow Terminal 4, and found it so successful that they decided to apply it at Wessex Water.

Last Planner is essentially a rolling one week and five-week ‘look ahead’ programme, whereby the construction manager decides with the trade contractors what work is going to be done, who is going to do it, and what the ‘make ready’ needs are in terms of materials and resources.

The day before the weekly Friday meeting, Mace requests a simple handwritten pro-forma submission from each of the subcontractors, detailing where they are in the project and how much of the previous week’s work has been achieved. This gives a very simple indication of whether the project is on programme, and whether the delays are likely to affect the critical path.

“If a delay does affect the critical path, then we strive to get the project back on track during the following week,” explained Gary Snowsill. “That might involve working on a Saturday, bringing in more labour or materials, or moving on to other areas while the materials are being sourced. Last Planner is a flexible tool, and more often than not people play the game,” said Snowsill.

Mace has found, not unsurprisingly, that the best performing companies on the Last Planner are those which have the best quality and the best safety records. “The ones that are always behind the mark are those who are traditionally a little bit behind anyway, particularly those that rely on subcontract labour,” revealed Snowsill; “and it’s materials and labour which cause the most problems.”

This careful planning highlighted the value of constructing builderswork holes for services routes well before detailed design. “As the brickwork contract was a full two months before the services contract, it made sense to locate the holes based on Bennetts’ and Buro Happold’s drawings, and just oversize them slightly,” said Gary Snowsill, “It seems so obvious, but it isn’t often done.”

Key Performance Indicators

So how has the project performed against industry norms? Figure 1 shows the latest estimates of the project’s performance against the M4I’s Key Performance Indicators (KPI). These indicators were devised by the M4I as a self-certification reporting method. The construction industry is scored by its clients on ten parameters including cost, productivity and defects.

The radar plot shows a high score for safety. With less than eight weeks left on the project there have been no reportable accidents. The defects score is also admirable, although the final fit out is likely to put a strain on this.

The predictability scores for cost and design time are relatively low – partially a reflection of initial groundwork delays that affected the entire build programme. Client satisfaction is also a relatively low score, but the team point out, not unreasonably, that the relevant KPI benchmark uses a very flat curve. So while a client’s score of 8/10 gives a 20% mark on the KPI, 9/10 gives nearer 70%.

The M4I openly admits the KPI weighting system is somewhat enigmatic. It seems reasonable to allow projects like Wessex Water to indulge in a little KPI re-engineering after the M4I issues the updated indicators.

With the project coming to a close, Mace is taking stock. Has supplier partnering delivered the results it was hoping for?

“Suppliers are not yet motivated in taking custody of environmental issues,” said Gary Snowsill. “If it isn’t written in the specification, suppliers and contractors will not bring much to the party,” he concluded frankly.