Energy costs
Commercial building cost breakdown
Anecdotal evidence suggests that a breakdown for the operating costs of a commercial building could be as follows.
| Cost category | % spend |
|---|---|
| Redecoration | 2 |
| Fabric maintenance | 8 |
| Services maintenance | 15 |
| Cleaning | 13 |
| Utilities | 35 |
| Administrative costs | 27 |
| TOTAL | 100 |
Typically, annual energy could account for £25-£30 per m2 of gross floor area and annual mechanical and electrical (M&E) maintenance for £20-£25 per m2 (at 2013 prices).
Energy costs are therefore likely to be the most cost-significant category for whole life costing (WLC) and will be influenced not least by:
- building function;
- specification;
- use of air-conditioning; and
- energy tariffs.
Value for money checklist
These questions will help the surveyor to confirm whole life value regarding energy.
- Does the building have to be air-conditioned?
- Have all the heating/cooling options been considered?
- Has the cooling load for office equipment been over-estimated?
- Is humidity control essential in winter?
- Fan-sensor control (in variable air volume (VAV) air-conditioning) can be significant in terms of whole life costing (WLC) - are we confident in the specification, installation and operation?
- Can a more favourable energy tariff be found and/or can the supplier be changed?
- Does the building use condensing gas boilers? (The average payback period is 3.2 years, according to the Building Research Energy Conservation Support Unit (BRECSU) Good Practice Case Study (GPCS) 039, Energy Efficiency in Offices - Condensing Gas Boilers.)
- Can the building use combined heat and power (where there is continuous demand)? (Payback period could be 4 years, according to Davis Langdon & Everest.)
- Does the building use compact fluorescent lamps (CFLs) and can it use high-frequency or electronic ballasts? (CFLs represent a significant saving on tungsten lamps - see GPCS 039 as above and the Good Practice Guide (GPG) 206: Energy efficient refurbishment of hospitals.)
- Does the building use lighting controls? (There are payback periods of 2-5 years - see GPG 206 as above.)
- Is the lighting level requirement over-estimated?
- Does it have efficient electrical office equipment?
- Is an energy-management system appropriate?
- Can the glazed area be reduced?
- Can higher insulation levels be used?