黑洞社区

Finding the best way to deliver high-quality projects quickly and effectively is a topic that continues to defeat the industry despite numerous experts proclaiming how it should be done. Latham, Egan, Morrell, Wolstenholme and now Hansford have produced reports which promote collaboration, innovation and sustainability as the answer to best value. In good times some of these ideas appear on the ground but the minute money gets tight the industry reverts to type - cut-price lump sum tenders, squeezed suppliers and back-to-basics projects that steer clear of risky innovation and expensive sustainability features.

So it is refreshing to see a job buck this trend and prove the approach promoted by this army of experts can work in the middle of a deep recession. The job is 240 Blackfriars Road, a 19-storey office building that will be the new home for UBM, the publishers of 黑洞社区 in 2015. It proves developers can deliver decent projects in a downturn without wreaking havoc on the supply chain. Developer Great Portland Estates, which are in a joint venture with BP called Great Ropemaker Partnership, wanted a high-quality building with decent sustainability credentials that would appeal to tenants in a difficult market. How has it got the most out of this site while keeping its supply chain happy?

Naturally GPE wanted to maximise the potential of a difficult, narrow site sandwiched between Blackfriars Road and a railway line. Planning was granted for a 14-storey tower in 2006 but the project was put on hold as the downturn kicked in.

When planning was granted for a 52-storey residential tower over the road, GPE saw it was more likely to get permission for a taller building so it redesigned the scheme by adding five extra storeys. GPE sees Southwark as a good place to develop and hold assets and decided early 2014 was a good time to hit what it hopes will be a resurgent market. It decided to press ahead with the substructure works before securing a prelet. The idea was it could hit the ground running with the main contract if a tenant signed up.

The building needed solid sustainability credentials to appeal to corporate occupiers and was designed to achieve a BREEAM Excellent rating. The original scheme complied with the 2008 version of BREEAM but by the time the scheme had been redesigned, BREEAM had been revised. A BREEAM 2011 Excellent rating was more onerous than the 2008 version, requiring 25% less carbon emissions than 2010 Part L. Meeting the latest standard entailed a significant redesign of the facade and services.

GPE decided that redesigning the scheme to meet BREEAM 2011 was worth doing despite a cost premium of 2% and no evidence of an uplift in rental premium. Why did it bother - as most people were unlikely to take much notice of the differences between a BREEAM 2008 and 2011 rating? GPE鈥檚 head of projects, James Pellatt, says relying on occupiers not to notice the difference was too risky. 鈥淲hile there isn鈥檛 an investment premium at the moment, we didn鈥檛 want to risk losing an occupier because of it,鈥� he says.

M&E engineer Hilson Moran had to cut carbon emissions by 21.5% over the original design. 鈥淲e looked at reducing energy use as a starting point,鈥� explains Andrew Grint, Hilson Moran鈥檚 project director. He says the facade was optimised to allow in as much light as possible while minimising solar gain and balancing the amount of heat that could be released through the facade. More efficient solar control glass was selected which allowed in the same amount of light while cutting solar gain. Fabric airtightness was improved from 5m³/m² hr@50pa to 3.5m³/m² hr@50pa.

More efficient chillers were specified and heat recovery on the air-handling units improved to 70%. Instantaneous local electric water heaters were swapped for more efficient centralised gas-fired boilers, and standard fluorescent lighting was ditched in favour of more efficient LEDs.

At the same time, GPE decided to increase the occupational density of the building from one person per 10m2 to one person per 8m2. 鈥淲e felt there was a trend towards increased density,鈥� explains Pellatt. 鈥淭his is usually done as a variation which is a headache so we decided to do this from day one as it costs less per desk.鈥�

Accommodating more people meant increasing ventilation rates and chiller capacities, putting further pressure on the BREEAM ratings. Larger air-handling units and ductwork was specified rather than increasing flow rates as this is more energy efficient. Larger chillers were needed too. Grint says these changes made very little difference to overall energy demand. 鈥淚n terms of the uplift in chilling capacity this is minimal compared to the overall cooling loads of the building,鈥� he says.

Squeezing in larger chillers and ductwork was a challenge as space for the services was already tight. Difficult ground conditions meant it was cheaper to locate the services on the roof. An unusual approach has been adopted to minimise the amount of space taken up by the services while allowing the top of the building to be used as habitable space. The top floor has been split diagonally with the front half used as lettable space. The other half of this floor plus another three levels above this house the services. A glass roof covers the area in front of the services installation to create a dramatic, triple-height top floor space with views of the sky.

BIM was used to work out how to shoehorn the services into this space. 鈥淚t鈥檚 a compact building services installation that is incredibly efficient,鈥� explains Grint. 鈥淏IM gave us the confidence that we could fit the plant in.鈥� The services in this area are at an early stage, but the boilers were installed at the end of June and were craned from ground level up to the top of the building. 鈥淲e would have never got these in if this hadn鈥檛 been modelled and co-ordinated with the steel frame and the suppliers,鈥� explains Mace鈥檚 project director Julian Bates. 鈥淚t鈥檚 the most complex plant room I have had the pleasure of building. It needed a lot of focus as we are 100m up in the air,鈥� he says. BIM provided certainty over the riser installation - these were prefabricated and were installed in a mere nine hours.

Unusually for a developer, GPE was the driving force behind the use of BIM on this job. 鈥淚t gives us greater certainty of outcome and a higher-quality job because it eliminates clashes onsite,鈥� explains Pellatt who had to persuade the GPE board to invest in BIM. GPE took BIM one stage further by deciding to take full ownership of the BIM data rather than leaving this to the project team. It employed consultant BIM Technologies to manage the BIM data.

GPE has taken BIM one stage further by asking BIM Technologies to create an 鈥渁s built鈥� model it can use for facilities management. It also took the unusual step of paying its supply chain for the time spent working with BIM. 鈥淚f we are paying for it, they are more likely to buy into the process and we get the information at the end for facilities management,鈥� explains Pellatt, adding that ensuring suppliers make a profit helps foster good long-term relationships.

Has the investment in BIM been worthwhile? Pellatt says it reduced the allocation of 5% for builders work associated with the M&E installation to 2.5% - enough to pay for the cost of BIM. Although many clients have reverted to the certainty and competitive advantage of single lump sum tenders, GPE preferred to go down the two-stage route due to the complexity of this building. But GPE wanted to keep the potential extra cost of a two-stage tender in check. 鈥淚 was keen to use BIM here because if we could co-ordinate the design, it would remove the risk pricing allocation,鈥� explains Pellatt. He adds the risk pricing allocation of 拢2m was reduced to 拢0.5m because risks could be much more easily identified with BIM.

Ensuring the building performs as designed is also an important focus for GPE. It has ensured there is plenty of time for services commissioning. 鈥淚f it is set up well, it will continue to run well,鈥� says Pellatt. 鈥淲e were promised a programme [by Mace] eight weeks quicker. We refused to accept this as we felt there wasn鈥檛 time to commission it properly.鈥� Pellatt adds the building will be seasonally commissioned once complete to ensure it is operating as efficiently as possible. He hopes this process will be simplified with the BIM FM information as this can be used to monitor how the building is performing and feed back into the seasonal commissioning strategy.

This strategy paid off as UBM, which has demanding carbon reduction targets to satisfy, signed a lease in January 2012 for the top nine floors. GPE is confident of filling the rest of the space citing interest from West End occupiers attracted by the lower rents in Southwark and the quality of the building. The project proves it is possible to deliver high-quality, sustainable projects equitably in a downturn.