An array of Balfour companies has been delivering luxury student digs for the University of Edinburgh.
Project: Holyrood student accommodation
Client: University of Edinburgh
Contract value: £67.5m
Contract type: Design, build, finance, operate
Funder: Balfour Beatty Investments
Main contractor: Balfour Beatty Construction
M&E subcontractor: Balfour Beatty Engineering Services
Concrete frame subcontractor: Stephenson
Piling subcontractor: Cementation Skanska
One area of the economy that seems to have survived all but the harshest ravishes of the recession is that of higher education.
The sector has grown to become a huge international business, and universities cannot afford to slip in offering higher quality facilities than the competition as they desperately try to woo students from across the world.
Even north of the border, where the Scottish Government still hasn’t brought in tuition fees for Scottish residents studying at Scottish universities, the fight to attract foreign students has seen increased investment in top-notch facilities.
One such example is the new student accommodation block being built within a stone’s throw of the Scottish Parliament building at Holyrood.
Balfour Beatty is in the process of constructing a complicated series of accommodation blocks for the University of Edinburgh on a small site within the city’s World Heritage Site under a £67.5m project.
The scheme will provide 1,165 separate student bedrooms across seven individual blocks on two patches of land within the heritage area.
“It is funded by Balfour Beatty Investments, being built by Balfour Beatty Construction and the mechanical and electrical work is being carried out by Balfour Beatty Engineering Services. It really is a cross-company project”
Alastair Moore, Balfour Beatty Construction
Of these, 900 will be on the larger northern section of the site, separated from the smaller southern area by the east to west-running Holyrood Road.
Both sections of the scheme are aiming for BREEAM Excellent and are intended for use by the multitude of postgraduate research students the university attracts, with the array of bedrooms and cluster flats designed to offer a high level of luxury and comfort.
Split into three phases, the construction team has a handover goal for the final phase of August 2016 - although the lion’s share of the accommodation will be delivered by August 2015.
Balfour Beatty Construction senior project manager Alastair Moore is the man charged with delivering the scheme under a bespoke design, build, finance and operate contract.
“The University of Edinburgh is the landowner and end user but Balfour Beatty itself has a huge role within the scheme,” he says.
“It is funded by Balfour Beatty Investments, being built by Balfour Beatty Construction and the mechanical and electrical work is being carried out by Balfour Beatty Engineering Services. It really is a cross-company project.”
Concrete over steel
The three different phases of the scheme differ slightly, but all share the same structural framing method, namely cast in-situ reinforced concrete.
“There are a number of reasons we went for a concrete frame over steel,” Mr Moore explains.
“At the time of procurement, steel prices were high and we felt that the stringent floor impact, vibration and acoustic requirements for these sort of schemes pointed naturally at a concrete solution.
“Our frame subcontractor Stephenson decided that by the time all the formwork and falsework had been positioned for the slabs, they could install the columns anyway. They were right.”
Alastair Moore, Balfour Beatty Construction
“Whatever time we might have won during the erection of the frame we would have lost carrying out any necessary follow-on works.”
Initially, the team felt the amount of repetition throughout the frames indicated a precast concrete solution could be used in conjunction with cast in-situ floor slabs, but this was eventually dismissed in favour of an all in-situ solution.
“Our frame subcontractor Stephenson decided that by the time all the formwork and falsework had been positioned for the slabs, they could install the columns anyway. They were right,” Mr Moore says.
The blocks on the north side all reach up to six storeys, with a steelwork pod forming the penthouse accommodation, springing from the fifth floor roof slab.
These all boast stunning rooftop views across Holyrood, Salisbury Crags and Arthur’s Seat, the extinct volcano that dominates the skyline in this part of town.
Tricky ground conditions
But ground conditions beneath these hefty reinforced concrete buildings with their 225 mm-thick floor slabs and 2,400 tonnes of steel reinforcement have been less than perfect.
Admittedly in the north-most end of the site the team has been able to cast the structures directly off the underlying carboniferous basalts that feature heavily in the area.
But farther down the site the situation changes. “There is a diagonal line that runs across the site,” Mr Moore explains.
“Above it we have been able to launch off the rock; below the line we have had to install piles.”
In all, there are 366 CFA piles across the site, all of 800 mm diameter with the deepest reaching 18 m into the underlying ground.
Of these, some 123 form a contiguous piled wall that runs the length of the Holyrood Road boundary of the north section of the scheme. It is this wall that retains the road and provides the basement level for the massive skylighted communal kitchen that will serve the bulk of the residents in the building.
“There is underfloor heating with several cooking ‘pods’ and seating throughout,” Mr Moore says. “Each student will be given an allocated storage cupboard.
“It is a model that has been tried in American universities to help bring the students together and help them socialise.”
The outside of the buildings are clad in a variety of façade systems, some 23,000 sq m in total, much of which will be lifted into position using the three tower cranes – two with luffing jibs and one with a saddle jib - that serve the site.
“We did think about using four cranes on the project but we thought it would become too congested and that there would be a danger the cranes could start ‘fencing’ with one another. Three has been ideal,” Mr Moore says.
With the prefabricated bathroom pods being manufactured in Kingston-Upon-Hull, delivered directly to site and lifted onto each floor of the building as work progresses, it is not just the Edinburgh skyline that is becoming congested.
There is precious little room for the team to manoeuvre.
Despite this, work has already started on the third phase of the development and Mr Moore is confident that not only will new students be enjoying the use of the communal kitchen facilities by August 2015, but also that he will not miss the final August 2016 handover date.
It might be a tough examination, but with the amount of funding still swilling around the higher education sector, it is one Mr Moore and Balfour Beatty cannot afford to fail.
The reach for BREEAM excellence
With the difficulty of meeting the BREEAM Excellent environmental target on both the north and south block, the team has taken something of a departure from the norm to help.
Aside from the early design to help facilitate the introduction of as many energy-efficient materials and systems as possible, the team has been fortunate enough to have been able to use the site’s close proximity to existing university buildings.
The University of Edinburgh already has its own large combined heat and power plant and owns much of the land around the development site.
The new-build site is taking advantage of both of these facts by tapping in to its existing CHP network and drawing in heating and power from elsewhere on the university’s campus.
“Basically there is an existing district heating and power system that we will be using,” Mr Moore says.
“The new system taps into that. We have also taken steps such as working on a green travel plan, working on bus routes and generally reducing traffic where possible.”
All’s well that ends well
The area of Edinburgh that surrounds the site has been well documented over the centuries as being rich in beer-brewing tradition, thanks largely to the clean spring and well water that abounds at the base of the volcanic rock plug that Edinburgh Castle is built upon.
Indeed, the very site was part of brewing giant Scottish and Newcastle’s landbank before being sold for development.
For the site team though, the existence of seven wells – three of which were unmarked on any plans – needed to be dealt with.
“One was 42 m deep,” Mr Moore says. “They all needed to have a 4 m-thick concrete plug and be backfilled with as dug, clean stone according to the Scottish Environment Protection Agency standard details.”
Meanwhile, further archaeological investigation across the site revealed that the first industrial use of the area had been that of leather tanning, while the survey managed to pinpoint the exact location of the old city boundary ditches.
These ditches were at the base of the walls to the city and were defensive installations.
Other finds during the archaeological survey included bronze pins and coins, pottery, clay pipes and animal bones dating back a far as the 12th century.