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Project details
Cost datum 4th quarter 2000
Location City of London
Gross office internal floor area (GIFA) 35 000 m²
Data centre net area 1000 m²
Procurement route Competitively tendered lump sum contract with contractor’s design responsibility
Design criteria
External design temperatures  
Winter -4°C (saturated)
Summer 28°C db/19°C wb
 
Internal design temperature  
Offices 22°C ±2°C
Fresh air ventilation 15 litres/s/person
 
Cooling loads  
Small power 25 W/m²
Cooling 375 W/m²
Primary power  
Equipment 550 W/m2
Lighting 12 W/m²
Lighting levels 400 lux
Cost breakdown
Space heating ventilation systems  
Upgrade to base building chilled water plant for enhanced cooling to data centre, serving 375 W/m², with redundancy to n+1 standard: 1000 m² at £285/m2 £285/³¾Â²
Chilled water distribution within data centre to free-standing cooling units, with associated water softening plant, condensate, insulation and humidification: 1000 m² at £325/³¾Â² £325/³¾Â²
Space heating & ventilating systems total £610/³¾Â²
 
Ventilation system  
Supply and extract ventilation, including dedicated gas extract system, low-level distribution, including floor grilles: 1000 m² at £135/³¾Â² £135
Ventilation system total £135/³¾Â²
 
Electrical installation  
Mains distribution with single incoming hv, generator backed lv switchgear, busbar and cabling distribution through ups system: 1000 m² at £50/³¾Â² £50/³¾Â²
Standby generators with redundancy to n+1 standard, controls, oil storage and distribution and flues. Generators located in the basement or on rooftops: 1500 kVA at £165/kVA £250/³¾Â²
UPS back-up system, 10 minute autonomy, European batteries, controls and distribution equipment located in plant area, redundancy n+1: 1600 kVA at £215/kVA £345/³¾Â²
Alternative specification  
Rotary diesel ups as alternative back-up to generators and ups, controls, oil storage and distribution and flues. Located in the basement or on rooftop areas, redundancy to n+1: 1500 kVA at £360/kVA saving of £55/m²  
Mains distribution  
LV switchgear, cabling, power distribution units and transfer switches to location in data centre. (six power distribution units at £22 000 plus allowance for distribution): 1000 m2 at £160/m2 £160/³¾Â²
Local power supplies  
Underfloor supplies to cabinets, dual feed in armoured radial feeds, terminating in BS4343 outlets, dual radial-feeds to mechanical plant: 580 feeds at £300 each £175/³¾Â²
Lighting  
Suspended luminaires, wiring and controls: 1000 m² at £35/³¾Â² £35/³¾Â²
Data containment  
Underfloor cable basket: 1000 m² at £20/³¾Â² £20/³¾Â²
Electrical installations total £1035/³¾Â²
 
Protective installations  
Sprinklers (pre-action type), storage tanks, pumps, pipework distribution, control values, alarm panels and controls. Data centre installation incorporated into main sprinkler system: 1000 m² at £35/³¾Â² £35/³¾Â²
Alternative specification: gaseous extinguishing system using inert gas. (An alternative to sprinkler systems, offering greater protection to equipment installed above and below the floor): 1000 m² at £280/m². Extra over-cost: £245/m² plus additional builder's work costs associated with strengthening partitions.  
Leak detection, installed adjacent to cooling plant pipework (generally to room perimeter): 250 m at £75/m £20/³¾Â²
Earthing and bonding: 1000 m² at £5/m2 £5/³¾Â²
Protective installations total £60/³¾Â²
 
Communications installations  
Addressable fire alarm and detection system providing full L1 cover plus interface to sprinkler system: 1000 m² at £30/m2 £30/³¾Â²
Extra for very early warning fire detection system, installation above and below raised floor: 1000 m² at £50/m2 £50/³¾Â²
Security installation, cctv, intruder detection and access control linked to main system, (based on 20 cameras and four card access points): 1000 m² at £75/³¾Â² £75/³¾Â²
Communications installations total £155/³¾Â²
 
Special installations  
ºÚ¶´ÉçÇø energy management system, controls and monitoring; interface with main building management system: 1000 m² at £45/³¾Â² £45/³¾Â²
Special installations total £45/³¾Â²
 
Total cost of data centre services  
Installation: £2040/³¾2
 
Exclusions  
inflation beyond 4th quarter 2000  
general builders’ work  
specialist builders’ work installations including: floor strengthening, blast protection, screening for electro-magnetic interference  
fit-out works beyond the boundary of the data centre except where stated in the scope of works  
external works, including enhanced hv supply capacity or dual hv feeds  
main contractor’s overheads, profit and attendance  
main contract preliminaries  
professional and prescribed fees  
contingencies and design reserve  
tax allowances  
vat  
Table 1: Cost summary
Element Range within
analysis		   Cost model %
Maximum Minimum    
£/³¾2 £/³¾2 £/³¾2  £/³¾2
Space heating and air treatment 595 650 610 29.9
Ventilation systems 125 150 135 6.6
Electrical installations 950 1155 1035 50.7
Protective installations 50 85 60 2.9
Communications installations 120 195 155 7.7
Special installations 40 50 45 2.2
Total 1880 2285 2040 100