Cost model: Tall buildings | Features

Cost breakdown
	Element cost	cost/m2 gfa £	% of total cost
Substructure	13,954,000	117.80	5.45%
Allowance for breaking out existing slabs and retaining walls Item @ 250,000
Allowance for preparatory work and dewatering all of the excavations Item @ 600,000
Foundations: large diameter bored piles, for example 40 m deep; 2 m thick ground slab 2,600 m2 @ 1,500
Extra for three-level basement construction: part secant piled walls, part diaphragm walls; insitu concrete frame and floors; waterproofing; drainage 7,800 m2 @ 1,000
Allowance for removal of obstructions Item @ 250,000
Allowance for treatment of contaminated surfaces 2,600 m2 @ 40
Allowance for temporary works Item @ 750,000
Allowance for lift pits, escalator pits, tower crane bases, etc Item @ 300,000
Frame	41,928,000	353.97	16.38%
Structural steel frame to upper floors, based on 200 kg/m2 overall (avg rate) 22,130 t @ 1,200
Secondary steelwork for cladding, trimming openings, etc 2,200 t @ 1,600
Extra for feature steel framing in reception/other areas Item @ 500,000
Fire protection to frame based on a combination of two-hour boarding and one-hour intumescent spray (avg rate used, based on 20 m2/tonne) 482,600 m2 @ 20
Allowance for concrete casing or infilling to some columns Item @ 500,000
Allowance for wind canopy structures Item @ 200,000
Allowance for additional ductile connections Item @ 1,000,000
Upper floors	8,146,000	68.77	3.18%
Composite floor construction; 130 mm thick reinforced insitu concrete; galvanized steel decking; total design load 4.5 kN/m2 110,650 m2 @ 55
Extra for 7.5 kN/m2 loading to plant and other areas 10,000 m2 @ 25
Extra for forming ramps, steps, and so on Item @ 500,000
Allowance for knock-out panels in upper floors construction Item @ 200,000
Allowance for lift pits, escalator pits, etc in upper floors construction Item @ 150,000
Allowance for insulation to edges of floor slabs 8,800 m @ 75
Extra for intermediate floors to atrium at six-storey intervals Item @ 300,000
Roof	1,657,000	13.99	0.65%
Waterproofing over external slab at ground level (over basements) 124 m2 @ 80
Composite roof slab construction, with waterproofing, insulation, ballast 2,350 m2 @ 200
Extra for access paving to 10% of roof area 250 m2 @ 75
Extra for stone paving to terraces 100 m2 @ 150
Architectural balustrading to roof terraces 50 m @ 550
Glazed atrium roof, with opening lights for ventilation/smoke extract; framing 200 m2 @ 1,200
Allowance for roof feature/screening to roof level plant Item @ 400,000
Allowance for perimeter safety rails, perimeter detailing & interface details Item @ 250,000
Allowance for plant bases and base for communication mast Item @ 50,000
Allowance for roof-level plant enclosures; structural steel frame; profiled aluminium raised seam roof cladding, insulation Item @ 175,000
Stairs	3,086,000	26.05	1.21%
Painted mild steel escape stairs in two straight flights, including all finishes 94 @ 16,000
Precast concrete stairs serving basements 8 @ 14,000
Allowance for feature staircases Item @ 900,000
Steel stairs within retail areas 8 @ 15,000
Allowance for disabled access provisions Item @ 250,000
Allowance for ladders and catwalks in plant rooms Item @ 200,000
External walls	61,264,000	517.21	23.94%
Triple glazed “active wall” facade system: double-glazed outer skin, single-glazed inner skin with opening lights; integral motorised blinds 51,000 m2 @ 875
Allowance for enhanced articulation in certain areas Item @ 5,000,000
Double-glazed atrium wall 3,700 m2 @ 1,000
Double-height glass wall system to ground floor, including all supports 800 m2 @ 1,500
Glass shop fronts 230 m2 @ 800
Louvres as external walling to plant floors/roof plant areas 3,100 m2 @ 550
Solid walls in loading bay/service yard Item @ 50,000
Unitised metal cladding to exposed core areas, and loading bay 8,000 m2 @ 450
Metal cladding to soffits Item @ 150,000
Allowance for entrance canopy/wind canopies Item @ 350,000
Allowance for mock-ups, testing and so on Item @ 700,000
External doors	916,000	7.73	0.36%
Double-glazed aluminium frame exit and fire escape doors 25 @ 4,000
High-quality motorised revolving doors and side doors for disabled access 4 @ 150,000
Shopfront automatic doors 8 @ 7000
Access doors to roof plant areas Item @ 40,000
Metal doors in service areas Item @ 30,000
Motorised security shutters to car park/loading bay entrance (including cladding interfaces) 2 @ 45,000
Internal walls and partitions	7,153,000	60.39	2.80%
Two-hour metal stud partitions around cores 29,100 m2 @ 90
One-hour metal stud partitions within core areas 17,900 m2 @ 55
Extra for shaft wall construction Item @ 500,000
Single-glazed wall around atriums 2,500 m2 @ 700
Block walls in basements and plant areas 4,200 m2 @ 50
Block walls dividing retail units 500 m2 @ 60
Cantilevered glass balustrade around mezzanine 22 m2 @ 1,200
Allowance for substation enclosure and access Item @ 200,000
WC cubicles, including doors and ironmongery 450 @ 1,250
Full height laminate-faced duct access panels to toilets 1,800 m2 @ 150
Internal doors	2,483,000	20.96	0.97%
High quality glazed double doors/side panels to lift lobbies 96 @ 7,000
Hardwood doors in core areas, fire-rated where necessary (average rate) 575 @ 1,350
Riser cupboard doors: fire-rated hardwood doorsets 490 @ 1,500
Metal doors in plant/service areas, 160 @ 1,250
Allowance for fire-rated access panels Item @ 100,000
Wall finishes	3,400,000	28.7	1.36%
Stone cladding to entrance lobby and lift lobbies 5,120 m2 @ 300
Allowance for feature wall in main reception Item @ 200,000
Finish to edges of slabs overlooking reception 22 m @ 300
Emulsion to core walls/plasterboard partitions & other walls 51,700 m2 @ 5
GRG circular casings to internal columns in office areas 3,000 m2 @ 175
Emulsion paint to service areas, plant rooms, facilities offices, storage areas 25,000 m2 @ 5
Good-quality ceramic tiling to toilets 6,885 m2 @ 100
Ceramic tiling in cleaners’ cupboards and service areas 1,000 m2 @ 60
Floor finishes	2,771,000	23.39	1.08%
Granite tiles to main entrance lobby, lift lobbies,
mezzanine areas and atrium base 4,100 m2 @ 300
Good-quality ceramic tiles to toilets, lightweight
concrete to make up levels 4,000 m2 @ 125
Raised floors to lift lobbies 2,580 m2 @ 37
Ceramic tiling to cleaners’ cupboards and service areas 350 m2 @ 50
Raised floor and good-quality carpet tiles to circulation areas 3,820 m2 @ 85
Epoxy paint on screed to plant and service areas 9,290 m2 @ 25
Sealer/hardener/wpm/wear course to loading dock,
service areas, car park 1,700 m2 @ 65
Allowance for making up levels in other areas Item @ 50,000
Allowance for linoleum to facilities offices, storage areas, and so on Item @ 30,000
Entrance mats and matwells Item @ 80,000
Allowance for sundry floor finishes in other areas Item @ 100,000
Ceiling finishes	1,879,000	15.86	0.73%
Feature ceiling to entrance lobby, mezzanine and lift lobbies 3,900 m2 @ 250
Non-standard metal suspended ceiling to circulation areas 3,820 m2 @ 100
Metal suspended ceiling to toilets 4,000 m2 @ 50
Paint finish to soffit of slabs to plant areas 9,290 m2 @ 10
Acoustic insulation lining to car park soffit 950 m2 @ 30
Allowance for other ceiling finishes/detailing Item @ 200,000
Furniture and fittings	4,092,000	34.55	1.60%
Granite vanity tops in toilets 650 m @ 1,100
Fittings to toilets (including allowance for disabled fittings) 4,000 m2 @ 500
Wall protection in goods lift lobbies 860 m2 @ 60
Main reception desk/screen Item @ 100,000
Main entrance and statutory signage; external signage Item @ 250,000
Car park bollards, column guards, entrance barriers Item @ 75,000
Cycle racking and cycle changing area fit-out Item @ 50,000
Dockmaster/security room fit-outs Item @ 30,000
Rubbish compactor/bailer Item @ 35,000
Allowance for main entrance features/fittings/objets d’art Item @ 500,000
Traffic management system Item @ 35,000
Allowance for sundry fittings Item @ 250,000
Sanitary fittings	785,000	6.63	0.31%
Allowance for WCs, basins, cleaners’ sinks, urinals (average rate used) 800 @ 700
Extra for disabled toilets 100 @ 2,000
Shower installations 20 @ 750
Water softeners 2 @ 5,000
Disposal installations	1,808,000	15.26	0.71%
Allowance for rainwater disposal 118,450 m2 @ 5
Soil waste and vent installation 118,450 m2 @ 9
Extra for drainage to retail units Item @ 150,000
Water installations	1,176,000	9.93	0.46%
Cold water: boosted rising main, bulk storage, treatment, etc 118,450 m2 @ 6
Hot water services by local electric water storage heaters 118,450 m2 @ 3
Water services for vending areas Item @ 60,000
Extra for supplies to retail units Item @ 50,000
Space heating and air treatment	15,728,000	132.78	6.15%
Gas installation Item @ 175,000
Low temperature hot water heating installation (including gas-fired boilers) 118,450 m2 @ 22
Air-conditioning installation: air-handling plant, refrigeration,
chilled water distribution for four-pipe fan coil installation to offices 118,450 m2 @ 70
Toilet extract installation 118,450 m2 @ 7
Smoke extract installation 118,450 m2 @ 12
Dedicated extract system for external wall void Item @ 1,150,000
Extra for smoke extract and ventilation to atrium spaces Item @ 600,000
Car park and loading bay extract ventilation 118,450 m2 @ 3
Stair/lobby pressurisation Item @ 300,000
Electrical installations	8,329,000	70.32	3.26%
Mains and submains installations 118,450 m2 @ 29
Power supply to mechanical plant 118,450 m2 @ 4
Small power installations 118,450 m2 @ 4
Power and controls for window blinds Item @ 450,000
Lighting, emergency lighting and small power to landlord’s areas 118,450 m2 @ 15
Lighting and emergency lighting to basement areas,
car park and loading bay 7,812 m2 @ 60
Allowance for enhanced lighting to reception and lift lobbies Item @ 600,000
Allowance for external lighting Item @ 200,000
Standby power installation (life safety systems only), including oil system Item @ 450,000
Lift installations	21,090,000	178.05	8.24%
21-person 1600 kg passenger lift 3 m/s serving low-rise floors 8 @ 600,000
21-person 1600 kg passenger lift 3.5 m/s serving mid-rise floors 8 @ 750,000
21-person 1600 kg passenger lift 6 m/s serving high-rise floors 8 @ 900,000
Goods lifts 3000 kg 3.5 m/s serving all floors above ground 2 @ 700,000
Passenger lift serving car park, doubling as fire-fighting lift 1 @ 150,000
Fire-fighting lifts serving all floors 2 @ 400,000
Escalators serving reception and mezzanine 4 @ 110,000
Car lift 2 @ 150,000
Protective installations	1,939,000	16.37	0.76%
Wet/dry riser installation, with pumps, etc 118,450 m2 @ 1
Sprinkler installation: common bulk storage, split pump sets 118,450 m2 @ 12
Hose reels including booster set 118,450 m2 @ 3
Lightning protection 1 @ 45,000
Communications installations	2,026,000	17.10	0.79%
Fully addressable fire alarm, smoke detection, voice alarm and
public address systems, interfaced to building management system 118,450 m2 @ 14
Primary containment for data and communications wiring 118,450 m2 @ 1
Security: CCTV/detection systems to building perimeter and in car park Item @ 250,000
Special Installations	2,640,000	22.29	1.03%
Building management system 118,450 m2 @ 13
Complete facade and atrium cleaning installations Item @ 1,000,000
Communications mast Item @ 100,000
Builder’s work in connection	2,775,000	23.43	1.08%
Builder’s work in connection with services installations,
including machine bases, steel stacking framework for double-height
plant, firestopping, holes, chases, etc (allow 5% of services costs) Item @ 2,775,000
Preliminaries and contingencies	44,850,000	378.64	17.53%
Construction manager’s pre-construction staff costs Item @ 1,000,000
Construction manager’s preliminaries, staff costs, overheads
and profit (allow 15%) Item @ 31,650,000
Design reserve and construction contingency (allow 5%) Item @ 12,200,000
Total for shell-and-core construction	255,875,000	2160.18	100%

Category A fit-out
	Element cost	cost/m2 gfa £	% of total cost
Based on net internal office area of 74,880 m2
Wall finishes	84,000	0.71	0.26%
Emulsion paint to external walls of cores and to internal columns 16,850 m2 @ 5
Floor finishes	4,568,000	38.56	14.12%
Medium-grade access floor; fire breaks; dust sealant 74,880 m2 @ 37
Carpet tiles 74,880 m2 @ 24
Ceiling finishes	3,370,000	28.45	10.42%
Concealed grid metal tray suspended ceiling to office areas;
acoustic quilt and fire breaks 74,880 m2 @ 45
Fittings	70,000	0.59	0.22%
Allowance for statutory signage Item @ 70,000
Space heating and air treatment	9,435,000	79.65	29.17%
Extension of four-pipe fan coil installation into office areas including
distribution ductwork; fan coil units; grilles and diffusers; insulation;
condensate drainage; interface with building management system 74,880 m2 @ 126
Electrical installation	5,616,000	47.41	17.36%
Lighting and emergency lighting to office areas;
power to fan coil units; supply only floor boxes
(small power distribution excluded); earthing and bonding 74,880 m2 @ 75
Communications installation	1,123,000	9.48	3.47%
Final connections to fire, smoke detection, alarm and public address systems 74,880 m2 @ 15
Protective installation	1,198,000	10.11	3.70%
Extension of sprinkler installations into office areas (one head per 9 m2) 74,880 m2 @ 16
Special installations	824,000	6.96	2.55%
Extension of building management system into office areas 74,880 m2 @ 11
Builder’s work in connection	503,000	4.25	1.56%
Allowance for associated builder’s work (say 4% of services costs) Item @ 503,000
Preliminaries and contingencies	5,550,000	46.86	17.16%
Construction manager’s preliminaries, staff costs,
overheads and profit (allow 15%) Item @ 4,000,000
Design reserve and construction contingency (allow 5%) Item @ 1,550,000
Total for category A fit-out	32,341,000	273.03	100%