Capital costs for services installations were previously examined in a cost model published in the September 1995 edition of Building Services Journal. The sample of projects the original model was based on were mostly designed prior to the issue of the British Council for Offices (BCO) Specification for urban offices. This guidance has subsequently been revised and was republished in 1997 as Best practice in the specification for offices.
Variations in the take-up of the BCO's recommendations has resulted in the application of a wide range of specification standards on urban office projects.
Table 1 summarises key design criteria extracted from the two editions of the BCO's guidance, together with the highest and lowest values identified from the study of the design criteria in a range of recent projects.
Project details
Cost datum 4 quarter 1998
Location City of London
Gross internal floor area (GIFA) 10 000 m2
Nett lettable area (NLA) 7200 m2
Procurement route Competitively tendered lump-sum contract with contractor's design responsibility
Project contract period 18 months
Value of main contract £15 000 000
Value of services subcontract £3 600 000
Main design parameters
External design temperatures
Winter -48C (saturated)
Summer 288C db/198C wb
Internal design temperature
Offices 228C%28C
Occupant density
Climate control 1:10 m2
Toilet provision 50/50@1:10 m2
Fresh air ventilation
15 litres/s/person
Primary power
Equipment 25 W/m2
Lighting 12 W/m2
Lighting
Office areas 400 lux
Cooling loads
Small power 25 W/m2
Lighting 12 W/m2
Supplementary cooling allowance
20 W/m2 over 30% of office area
Public health installation
Sanitary fittings
WC suites, wash basins, cleaner's sinks, disabled toilet facilities to each floor
£4.50/m2GIFA
£6.25/m2 NLA
Domestic hot water
Local electric heaters, pipework distribution, insulation and trace heating
£3.00/m2 GIFA
£4.15/m2 NLA
Disposal – condensate drainage
Pipework and insulation in riser stacks
£0.60/m2 GIFA
£0.85/m2 NLA
Disposal – soil, waste and ventilation system
Above ground internal pipe–cast-iron and uPVC
£7.00/m2 GIFA
£9.70/m2 NLA
Disposal – rainwater
Above ground internal cast-iron drainpipes and roof gullies, connections to below ground drainage
£4.00/m2 GIFA
£5.55/m2 NLA
Cold water services
Mains incoming water service, storage tank, booster pumps, pipework distribution, water treatment and insulation
£6.60/m2 GIFA
£9.15/m2 NLA
Public health total
£25.70/m2 GIFA
£35.65/m2 NLA
Mechanical shell & core services
Heat source
Gas-fired boilers approximately 900 kW. Duty, twin-walled stainless steel flues, gas supply
5.75/m2 GIFA
£8.00/m2 NLA
LTHW installation
Pipework distribution in plantrooms, cores and risers, pump, pressurisation unit, water treatment, insulation, trace heating, radiators/convectors to circulation areas, over door heaters to entrance
£8.50/m2 GIFA
£11.80/m2 NLA
Chilled water installation
Roof-mounted, air-cooled packaged chiller plant approximately 1000 kW. Duty, pipework distribution in plantrooms, cores and risers, pumps, pressurisation unit, water treatment, insulation, trace heating
£23.50/m2 GIFA
£32.65/m2 NLA
Toilet ventilation
Extract plant, ductwork, grilles, insulation and attenuation
£7.80/m2 GIFA
£10.80/m2 NLA
General ventilation
Mechanical ventilation to basement, plantrooms and oil storage; fire rated ductwork
£7.20/m2 GIFA
£10.00/m2 NLA
Air conditioning
Supply and extract air handling plant, humidification, ductwork, insulation in plantrooms, cores and risers
£16.00/m2 GIFA
£22.20/m2 NLA
Staircase and lift lobby pressurisation
Extract fan, ductwork and grilles
£4.50/m2 GIFA
£6.25/m2 NLA
Building energy management system
Centralised energy management system comprising motor control centres, isolators, starters and all controls, outstations, riser network and monitoring, including head-end equipment
£19.75/m2 GIFA
£27.45/m2 NLA
Testing and commissioning
Testing and commissioning of mechanical and public health installations, plus operating and maintenance manuals and record drawings
£2.70/m2 GIFA
£3.75/m2 NLA
Mechanical services total
£95.70/m2 GIFA
£132.90/m2 NLA
Fire protection – shell & core
Dry riser
Riser including landing valve and inlet box
£1.50/m2GIFA
£2.10/m2 NLA
Hose reels
Storage tanks, total capacity 100 m3, booster pumps, pipework distribution and 16 hose reels
£2.60/m2 GIFA
£3.60/m2 NLA
Sprinkler installation
Storage tanks, booster pumps, pipework distribution, control valves and alarm panels in plantrooms, cores and risers (OH3)
£12.00/m2 GIFA
16.65/m2 NLA£
Fire protection total
£16.10/m2 GIFA
£22.35/m2 NLA
Electrical shell & core services
Mains/sub-mains distribution
Package substation,lv switchgear, essential services switchgear,hv cabling, distribution boards,lv sub-mains cable distribution, rising busbar and cable containment system
£.20.80/m2 GIFA
£28.90/m2 NLA
Standby generator
150 kVA generator for landlord's services only, acoustic enclosure, control panel, oil storage and distribution
£7.00/m2 GIFA
£9.70/m2 NLA
Small power
Power outlets to landlord's areas
£5.75/m2 GIFA
£8.00/m2 NLA
Electrical works associated with mechanical services installation
£4.00/m2 GIFA
£5.55/m2 NLA
Lighting
Luminaires and wiring to landlord's areas
£10.60/m2 GIFA
£14.70/m2 NLA
Lighting control system to landlord's areas
£2.50/m2 GIFA
£3.50/m2 NLA
Security installation
CCTV installation, intruder detection, intercom and access control containment
£3.60/m2 GIFA
£5.00/m2 NLA
Voice/data wireways
Cable tray in risers
£0.40/m2 GIFA
£0.55/m2 NLA
Fire alarm
Fully addressable fire alarm and smoke detection installation to L1 BS 5839, including spare capacity for future tenant extension
£7.40/m2 GIFA
£10.30/m2 NLA
Earthing and bonding
£2.00/m2 GIFA
£2.80/m2 NLA
Lightning protection
£1.00/m2 GIFA
£1.40/m2 NLA
Electrical services total
365.05/m2 GIFA
£90.40/m2 NLA
Category a fit out
Mechanical services, public health services and fire protection
Four pipe fan coil air conditioning installation comprising chilled water pipework distribution, lthw pipework distribution, primary and secondary ductwork and fan coil units (average one per 27 m2 NLA at perimeter and one per 50 m2 NLA in internal zones)
Chilled water pipework distribution and insulation
£20.40/m2 GIFA
£28.30/m2 NLA
LTHW pipework distribution and insulation
£12.80/m2 GIFA
£17.80/m2 NLA
Primary and secondary ductwork
£25.00/m2 GIFA
£34.80/m2 NLA
Condensate drainage
£2.65/m2 GIFA
£3.70/m2 NLA
Fan coil unit distribution
£16.20/m2 GIFA
£22.50/m2 NLA
BEMS/controls installation including individual intelligent water side control to each fan coil unit
£9.50/m2 GIFA
£13.20/m2 NLA
Sprinkler installation (OH3)
£12.75/m2 GIFA
£17.70/m2 NLA
Testing and commissioning
£4.00/m2 GIFA
£5.60/m2 NLA
Total
£103.30/m2 GIFA
£143.60/m2 NLA
Electrical services
Modular fluorescent luminaire to LG3 category 2, high frequency, dimming, (one per 4·5 m2); including emergency packs, trunking, conduit, wiring and accessories
£27.40/m2 GIFA
£38.00/m2 NLA
Lighting control system with facility for enhancement by tenant
£5.30/m2 GIFA
£7.30/m2 NLA
Underfloor power distribution system with floor outlet boxes at one per 10 m2
£12.00/m2 GIFA
£16.70/m2 NLA
Small power associated with fan coil units
£1.45/m2 GIFA
£2.00/m2 NLA
Fire alarm and smoke detection installation, fully addressable to L1
£6.50/m2 GIFA
4£9.00/m2 NLA
Earthing and bonding
£0.55/m2 GIFA
£0.75/m2 NLA
Total
£53.20/m2 GIFA
£73.75/m2 NLA
Total Category A fit-out cost
£156.50/m2 GIFA
£217.35/m2 NLA
Source
Building Sustainable Design
