Cost model: Office refurbishment | Features

Extent of refurbishment	Indicative cost (£/m2 gifa)
Minor refurbishment	300–825
Medium refurbishment	825–1,450
Major refurbishment*	1,450–2,100-plus
*includes category A fit-out.
Costs current at 2Q08 for central London location

	£	£/m2 GIFA	%
Demolition and alterations	3,163,300	265.82	17.57
Allowance for strip-out: item @ £500,000
Allowance for general demolition works, services strip-out, asbestos removal, temporary propping: item @ £560,000
Alterations to existing lightwell walls, including blocking up and enlarging existing openings, work to windows, etc: item @ £340,000
Breaking out local areas of existing load-bearing masonry, temporary support, forming new padstones, disposal: item @ £100,000
Demolish load-bearing walls and chimneys and adjacent upper-floor structure, temporary support, padstones, new steel structure: item @ £600,000
Demolish load-bearing walls and chimneys and adjacent upper-floor structure, temporary support, padstones, new steel structure: item @ £600,000
Propping load-bearing wall structure to allow insertion of structural steel: item @ £150,000
Demolish existing non-load-bearing walls, disposal: 1,860m2 @ £35
Break out floor slabs in isolated areas: 1,035m2 @ £120
Localised breaking out of slabs to insert structural steel: 800 nr @ £340
Infill existing slabs where structure removed: 1,600m2 @ £260
Alterations to pavement lights to form ventilation openings, waterproofing: item @ £36,000
Substructure	257,900	21.67	1.43
Alterations to drainage: item @ £65,000
Underpinning existing structure: item @ £80,000
New core foundations, including breaking through existing slabs, excavation, disposal, 1,000mm-deep reinforced concrete raft foundation: 170m2 @ £570
New basement slab to cores, 150mm thick: 200m2 @ £80
Frame and upper floors	3,053,400	256.59	16.96
Structural steelwork generally; UB and UC sections, erection, fire protection: 470t @ £2,500
Extra over for erection within existing structure, including connection details, splicing, etc: 470t @ £2,000
130mm-thick reinforced concrete slab on permanent formwork, including reinforcement as infill to stair cores and lightwells: 1,090m2 @ £110
Alterations to retained upper-floor structure, strengthening and sealing on both sides in structural plywood: 7,350m2 @ £100
Fire barriers to risers with open-mesh plant platforms: 250m2 @ £190
Allowance for the testing and replacement of existing eye-bolts: item @ £36,000
Roof	1,233,000	103.61	6.85
Allowance for repairs to existing roof: item @ £340,000
Roof-level steelwork, erection, fire protection: 78t @ £2,000
Insitu concrete roof slab; metal deck and insitu concrete, including upstand and works to existing parapet: 280m2 @ £170
Single-ply roof membrane, including insulation, paving slabs: 320m2 @ £160
Open mesh flooring to plant deck: 440m2 @ £150
Mansard roof, including rafters, slate tiles, flashings, etc: 1,190m2 @ £280
Allowance for new aluminium rainwater goods; detailing to existing building: item @ £125,000
Sheet cladding to new lightwell: 400m2 @ £160
Access ladders, latchway, stairs to platforms and galvanized roof balustrading: item @ £50,000
Stairs	184,000	15.46	1.02
Main steel internal staircases; handrails and balustrades (rate per flight): 18 nr @ £8,000
Additional stairs, balustrades and handrails: item @ £40,000
External walls, windows and doors	1,177,200	98.92	6.54
Allowance for repairs and cleaning to existing facade, including upgrade to insulation: item @ £410,000
New glazed office entrance screens: item @ £140,000
Secondary glazing to existing windows, including blinds: 1,000m2 @ £190
Allowance for renovations to existing windows and glazed doors, including replacement ironmongery: item @ £250,000
Plant area louvres: 560m2 @ £300
Allowance for temporary hoardings to retail units, 4m high: 480m2 @ £40
Internal walls and partitions	82,900	6.97	0.46
Reinforced concrete walls to lift pit, 100mm-thick: 28m2 @ £120
150mm-thick blockwork walls: 930m2 @ £50
Additional masonry in core walls and infill to voids: item @ £33,000
Internal doors	285,800	24.02	1.59
MDF-faced non-fire-rated doors, ironmongery (average rate per leaf): 175 nr @ £850
Laminated-faced, 30-minute fire-rated doors, ironmongery (average rate per leaf): 70 nr @ £1,100
Glass doors, 30-minute fire-rated doors, ironmongery, single-leaf only: 20 nr @ £3,000
Wall finishes	529,600	44.50	2.44
Reception finishes, stone cladding and timber panels: item @ £140,000
Lobby finishes, timber panels: 90m2 @ £400
Plasterboard lining to existing perimeter walls and window reveals, skim coat: 6,400m2 @ £30
Column casings; skim coat: 1,000m2 @ £60
Emulsion paint to existing perimeter walls, lightwell walls, columns: 7,400m2 @ £4
Dust sealer to basement and ground-floor walls: 2,000m2 @ £6
Allowances for enhanced finishes: item @ £60,000
Floor finishes	138,800	11.66	0.77
Stone and composite floor tiling, average rate: 280m2 @ £200
Extra for lightweight concrete infill: 100m2 @ £300
Rubber and vinyl tiles including skirtings, screeds, average rate: 290m2 @ £80
Carpet tiles including skirtings, screeds: 160m2 @ £60
Entrance mats: item @ £10,000
Allowance for floor sealers: item @ £10,000
Ceiling finishes	359,900	30.24	2.00
Plasterboard suspended ceiling: 795m2 @ £40
2 layers of plasterboard as ceiling lining: 795m2 @ £40
1 layer of plasterboard ceiling to offices areas including skim coat: 7,350m2 @ £30
Paint finish: 8,940m2 @ £4
Allowance for feature ceilings in landlord’s areas: item @ £40,000
Furniture and fittings	179,200	15.06	1.00
Reception desk: item @ £35,000
Allowance for additional furniture in landlord’s areas: item @ £15,600
Fitting out to WCs, including vanity units, towel rails etc: 31 nr @ £2,600
Signage – directory and statutory: item @ £30,000
Fire extinguisher cabinets: item @ £18,000
WCs, basins and sundry fittings: 31 nr @ £2,750
Extra for fittings for disabled toilets: 11 nr @ £950
Cleaners’ sink and taps: 6 nr @ £800
Disposal installations	123,000	10.34	0.68
Waste, soil and vent pipework: 10,250m2 @ £8
Rainwater installation: 10,250m2 @ £4
Hot and cold water installations	82,000	6.89	0.44
Hot and cold water installation; incoming supply, localised water heaters: 10,250m2 @ £8
Heating air treatment and ventilation	854,800	71.83	4.75
Modular boiler plant, plant room and riser distribution: 10,250m2 @ £28
Chiller, plant room and riser distribution: 10,250m2 @ £19
Air-handling unit and riser ductwork: 10,250m2 @ £32
Entrance area ventilation and cooling: item @ £21,000
Toilet extract ventilation: item @ £24,000
Electrical installation	823,500	69.20	4.58
New incoming supply: item @ £173,000
LV mains and sub-mains distribution: 10,250m2 @ £24
Small power to landlord’s areas: 10,250m2 @ £6
Electrical supplies to mechanical plant: 10,250m2 @ £8
Lighting to basement and landlord’s areas: 3,650m2 @ £40
Enhanced lighting in reception and other areas: item @ £105,000
Allowance for capped-off supply to retail units: item @ £10,000
Gas installations	12,000	1.01	0.20
Incoming gas supply: item @ £12,000
Lift installations	396,000	33.28	2.14
13-person (1,000kg) electric passenger lifts, 1.6m/s: 3 nr @ £132,000
Protective installations	38,500	3.24	0.21
Lightning protection: item @ £14,500
Earthing and bonding: item @ £24,000
Communication installations	216,800	18.22	1.21
Fire alarm and smoke detection: 10,250m2 @ £9
Intruder alarm: item @ £20,000
Disabled WC alarm system and wheelchair refuge call points: item @ £21,000
CCTV allowance for six cameras: item @ £15,500
IT containment and security wireways: item @ £68,000
Specialist installations	164,000	13.78	0.91
BMS controls: 10,250m2 @ £16
Builder’s work in connection	420,000	35.29	2.33
Builder’s work generally: item @ £420,000
Preliminaries and contingencies	4,125,900	346.55	22.91
Management costs, site establishment and site supervision. Contractor’s preliminaries, overheads and profit @ 22%: item @ £3,070,000
Allowance for design reserve @ 3%: item @ £970,000
Testing and commissioning of building services installations: item @ £60,000
Total construction cost (shell and core)	18,000,000	1,512.60	100.00
(m2 rate based on GIFA)

	£	£/m2 GIFA	%
Floor finishes	555,100	54.16	17.59
Raised access floor: 7,525m2 @ £40
Allowance for mechanical fixing of pedestals: item @ £30,000
Carpet to raised access floor: 7,525m2 @ £25
Hardwood skirtings, painted: 1,800m @ £20
Furniture and fittings	30,000	2.93	0.95
Window blinds: item @ £30,000
Heating, air treatment and ventilation	1,021,700	99.68	32.28
Low-temperature hot-water distribution to Hiross units: 7,350m2 @ £11
Chilled water distribution to Hiross system, condensate drain: 7,350m2 @ £20
Hiross under-floor air-conditioning units, return air grilles: 7,350m2 @ £108
Electrical installation	690,900	67.40	21.83
Distribution boards: 7,350m2 @ £4
Lighting installation and controls: 7,350m2 @ £18
Luminaires, emergency lighting: 7,350m2 @ £66
Small power: 7,350m2 @ £6
Communications installations	58,800	5.74	1.86
Fire alarms: 7,350m2 @ £8
Special installations	51,500	5.02	1.63
BMS: 7,350m2 @ £7
Preliminaries and contingencies	757,000	73.85	23.92
Management costs, site establishment and site supervision; contractor’s preliminaries, overheads and profit @ 22%: item @ £530,000
Testing and commissioning of building services installations: item @ £25,000
Allowance for design reserve and construction contingency @ 7%: item @ £202,000
Total construction cost (cat A fit-out)	3,165,000	308.78	100%
(m2 rate based on GIFA)

The cost breakdown should be adjusted by the following location factors for schemes in regions outside central London:
Inner London	1.00
Outer London	0.94
South-east England	0.92
South-west England	0.88
East Midlands	0.85
West Midlands	0.85
East Anglia	0.88
Yorkshire and Humberside	0.88
North-west England	0.83
Northern England	0.91
Scotland	0.92
Wales	0.87
Northern Ireland	0.69