Contractor Speller Metcalfe has been working with Western Power Distribution across its estate to reduce carbon emissions, increase sustainability and improve the BREEAM ratings of WPD’s buildings.
- Reducing the physical footprint to lessen the carbon footprint
- Fabric-first approach throughout
- The technical challenges of retrofit
- Live sites and local supply chains
- Understanding is vital to achieving sustainability
- Case study: New build and refurbishment
A typical BREEAM assessment can take several months from the initial design stage through to certification. Speller Metcalfe, however, has been completing the process in just eight weeks during its contract with Western Power Distribution.
The company’s Ecobuild division, headed by environmental manager Adrian Speller, advises on all the company’s projects from the conceptual design stage right through to construction to make sure all aspects of sustainability have been considered – and BREEAM requirements are integrated into the process.
“BREEAM looks across the whole scope of a project when calculating its ratings,” Mr Speller says. “While it has traditionally taken longer to complete the certification process, we have proven that it is possible to deliver high standards of sustainability in a shorter time period.”
The firm began working with WPD in August 2011 and is now on its ninth project with the electricity distributor. “It did help that we had the experience of working on sustainable projects,” Mr Speller says. “It proved to WPD that we could deliver what they needed as they undergo something of a reorganisation.”
Reducing the physical footprint to lessen the carbon footprint
WPD is moving away from using large depots with big physical footprints to smaller depots serving more compact regional areas. As part of this, Speller Metcalfe is working on a number of smaller new-build depots to replace the larger one and is refurbishing the existing buildings to reach higher levels of sustainability.
“We have proven that it is possible to deliver high standards of sustainability in a shorter time period”
Adrian Speller, Speller Metcalfe
“WPD is really aiming to go green, even while many others in that industry are holding off due to the perceive cost,” Mr Speller says. “We have been tasked with refurbishing a number of their existing depots up to BREEAM Very Good standard, with all new builds expected to achieve a BREEAM Excellent rating.”
Speller Metcalfe has already completed a number of projects for WPD. It carried out a range of refurbishment and extension projects at Burton-on-Trent, Milton Keynes, Northampton, Kettering, Leicester and Hinkley, and is currently constructing new depots at Barnstable and Boston.
The company has embraced technology on the projects, using building information modelling effectively on the new-build depots.
This allowed Speller Metcalfe to simulate how much energy buildings would consume, by linking BIM to environmental analysis software to save time in carrying out SBEM energy usage calculations. Accurate 3D visualisations also allowed the company to engage more effectively with WPD and produce more cost-effective designs.
Fabric-first approach throughout
One of the guiding principles of the retrofit and new-build programme undertaken by Speller Metcalfe was the fabric-first approach taken by the contractor.
“We were always very careful to take this approach and use these techniques,” Mr Speller says. “This is where we worked to avoid thermal bridging through the use of integrated claddings, and made sure to install new windows where needed.”
The team then added low- or zero-carbon technology including photovoltaic energy systems, energy-efficient lighting linked to PIR motiondetection, major leak detection and sanitary supply shut-off systems, and heat recovery variable refrigerant flow technologies.
Mr Speller says PVES was particularly well-suited to these projects. “Most of the buildings we worked on had large, sloping roofs,” he says. “This meant there was an ideal surface for PVES and we used them throughout.”
The technical challenges of retrofit
Some of the most technically interesting work came from the retrofit projects, which included recladding the old structures and considering how best to insulate them.
“A lot of the work was refreshing old buildings and bringing them up to modern environmental standards,” Mr Speller says. “We had to ensure there was no thermal bridging and that buildings were properly insulated.”
At the Northampton project, Speller Metcalfe was faced with a site that had been partially demolished, with only the steel frame and door slab remaining. “We turned that project around in only eight weeks, completing around £2m-worth of work in that period,” Mr Speller says.
“We usually use local subcontractors wherever possible, as it is often more cost-effective”
Adrian Speller, Speller Metcalfe
The firm created a new depot for the client with new roof and wall cladding based on the old steel frame. Mechanical and electrical services were also incorporated in the contract, along with the erection of new external walls and an extensive fit-out.
The building achieved a BREEAM Very Good – something Speller Metcalfe has achieved on six projects it has worked on with WPD.
“WPD is very committed to sustainability rather than focusing solely on costs,” Mr Speller says. “But there was still a big effort made to fast-track projects through the BREEAM rating process.”
The client’s cost requirements were also a factor in working towards fast project completion times. “As most of these projects occurred on live sites, the quicker we could get the client’s staff back into work and on site again, the lower the costs would be for them,” he says.
Live sites and local supply chains
The issue of working on live sites also proved to be a major challenge. Most of the depots were still operating as construction and refurbishment work took place around them.
Speller Metcalfe had to work around this and alongside the client’s staff, a process that involved a great deal of work outside office hours. Work was heavily phased in order to achieve this and minimise disruption for the client.
While the firm has been working with WPD throughout its regional coverage in the West Midlands and the South-west, Mr Speller says this has proved to be something of a challenge, too. “It has been difficult to engage our supply chain all over the country,” he says.
“We usually use local subcontractors wherever possible, as it is often more cost-effective. We made sure to thoroughly research what was available in each area before each project.”
He says, however, that the firm did find some subcontractors who were willing to travel. “We tried to find some who were able to come to different sites around the country,” he says.
“This was an advantage as you use someone who you know will do the job to the required standard.”
Understanding proves vital to sustainability
The high number of consecutive projects for the same client has allowed Speller Metcalfe to continually hone its delivery throughout its time working with WPD.
“While these aren’t necessarily the most exciting buildings in the world, they have allowed us to use ongoing collaborative methods to great effect,” Mr Speller says.
“We’ve used the same team on almost all of the projects, which has meant we have been able to learn as we have gone along. We have been able to tweak the process as many times as we’ve needed to.”
“Sustainability won’t increase until there are regulations demanding higher minimum standards”
Adrian Speller, Speller Metcalfe
The success of the contract has not only benefited WPD in improving its green credentials as a company, but has also saved it money. Across its three new sites, photovoltaic cells have generated 12,390 kWh to give a combined annual saving of £4,920.
Mr Speller also estimates that the accelerated timeframe and standardised design details resulted in a time saving of at least 25 per cent.
This resulted in a steady workflow for Speller Metcalfe as the electricity distributor came to trust them to deliver the work. “We can transfer what we’ve learned here to other projects,” Mr Speller says.
He hopes this will also help the firm win more work in the future. “Our success here means that we can sell our sustainability expertise in prequalifications, helping us to win more work of this nature,” he says.
The firm’s dedicated Ecobuild division shows the importance that it places on sustainable building practices. Mr Speller works with a range of projects in a variety of sectors to ensure that they meet exacting environmental standards.
He thinks that more could be done, though, and that the government has to take the lead.
“Sustainability is very much worth pursuing as it lowers costs in the long run,” he says. “It needs to be driven by legislation. It won’t increase until there are regulations demanding higher minimum standards. If we see this, then things will begin to change faster.”
Case study: New build and refurbishment
Location Barnstaple, Devon
Duration 27 weeks
Timescale December 2012 – June 2013
This is the seventh contract that Speller Metcalfe has undertaken for Western Power Distribution. The works are taking place on a live site, with works being phased accordingly to allow WPD staff to work as normal.
Phase 1 will see the construction of a new build garage. The steel-framed structure will provide storage and vehicle repair services to the North Devon depot, WPD’s largest in the area.
Phase 2a sees the refurbishment of the existing store, while phases 2b, 3 and 4 include office refurbishments and fit-outs. These will be completed in rolling phases to allow workers to be moved into temporary accommodation as and when required. Speller Metcalfe is working closely with WPD to allow the client continual access to the site throughout.
The entire project is being fast-tracked and completed to BREEAM Excellent standard. A fabric-first approach is being used alongside BIM on the new build to ensure maximum sustainability is achieved.