The Workplace (Health, Safety and Welfare) Regulations 1992 (Statutory Instrument 1992 No, 3004) require only that: 'During working hours, the temperature in all workplaces inside the building shall be reasonable.'
Section 1 (Environmental criteria for design) of CIBSE Guide A: Environmental design, suggests for offices that the temperature range for comfort should be 21-23ºC in winter and 22-24 ºC in summer. The latter range applies to air conditioned buildings. Higher temperatures may be acceptable in non-air conditioned buildings.
Looking at the workplace environment holistically one of two of these areas in isolation will not be overtly detrimental i.e. for a few days in the peak of summer or winter temperature highs and lows outside of the normal are to be expected. There has been no clearly defined link to work rate or health suffering due to a short term increase / decrease in temperature in the workplace.
That said most companies or places of study will want their employees to feel comfortable within that work or study environment.
Aside from air conditioning / radiators and double glazing (depending on whether you are looking to increase or decrease temperature) other solutions to consider are:
- Window film protection from solar gain
- Moving desk positions awasy from radiators / windows to stop radiant heat
- Freestanding or ceiling mounted fans (run at a fraction of the cost of aircon)
- Low wattage computers and lighting systems