Whole-life costs: Primary schools | Features

Base building, single-storey primary school
Basic information
Gross internal floor area	3912 m2
Construction	Steel frame of 37 kg/m2
Substructure	200 mm ground-bearing slab
Roof	Pitched, aluminium standing seam
External walls	103 mm brick-faced cavity wall
Window frames	Aluminium
Windows	Double-glazed, low-emissivity glass
Capital costs (£)
Substructure	574,262
Structure	279,893
External envelope	1,167,584
Internal divisions	329,444
Fininshings and fittings	941,967
Mechanical	493,971
Electrics and communications	574,573
Builders’ work	22,005
Preliminaries	837,848
Total	5,221,548
Net present costs for key components (£)
Space heating	4,276
Fans	203
Other energy costs	7,478
Total (over 30-year period)	11,957
Replacement and maintenance costs per year (£)
Roof	5,993
Rooflights	2,814
Roof drainage: gutters	7,850
Rainwater downpipes	5,339
External walls	54,337
Windows	18,775
External doors	3,402
Redecoration	44,286
Window blinds	26,343
Heat source	47,930
Light fittings	20,018
Total	237,088

Energy cost changes for increased ceiling height and more glazing
		Cost/yr £	Percentage change
Fabric heat losses		187	10.3%
Ventilation losses	Mechanical vent	96	11.1%
	Infiltration and leakage	35	3.5%
Solar gains		-75	26.4%
Heat gains from lights		8	-4.8%
Fans		25	12.3%
Lighting		-81	-4.6%
TOTAL CHANGE PER YEAR		195	2.0%
SPACE HEATING
COOLING
OTHER ENERGY

Scenario 1: An increase in ceiling height and glazing – repair and maintenance costs
The graph right shows an increase in net present cost of £24,100. The slight reduction on light fittings assumes that the lamp life reduces slightly as the lights will be switched on less often.
Over 30 years, the combined effect for a change of increase in the ceiling height, mainly for high-level glazing, are:
Capital cost changes	+£140,000
Energy cost changes	+£3,500
Maintenance and replacement changes	+£24,100
Total change in net present cost	+£167,600

Energy cost changes for going from one to two storeys
		Cost/yr £	Percentage change
Fabric heat losses		-473	-23.6%
Ventilation losses	Mechanical vent	6	0.7%
	Infiltration and leakage	-342	-29.9%
Solar gains		-12	4.4%
Heat gains from lights		-2	1.2%
Fans		2	1.0%
Lifts		39	NA
General power		16	0.6%
Lighting		25	1.4%
TOTAL CHANGE PER YEAR		-741	-6.2%
SPACE HEATING
COOLING
OTHER ENERGY

Scenario 2: Adding another floor and reducing footprint – repair and maintenance costs
The combined effect for a change from single to two-storey construction:
Capital cost changes	–£118,000
Energy cost changes	–£13,500
Maintenance and replacement changes	+£5,500
Total change in net present cost	–£126,000
The main economic advantage of using two storeys rather than one, is not normally construction costs, but the conservation of land.