In order to help businesses reduce the environmental impact, and as a result cut costs, the firm has teamed up with the Building Research Establishment to produce The Office Toolkit.
It claims the guide could save most offices between pounds 200 and pounds 400 per employee annually, while those that previously had no environmental policy could see savings that amount to a fifth of their operating costs.
Since there are about 12 million office workers throughout Britain, the total savings possible by controlling impact on the environment are about pounds 2.4bn, says PA.
The savings can come through such straightforward initiatives as switching off lights and personal computers.
Leaving PCs on is especially expensive. The machines can add more to the office electricity bill than lighting or heating, according to research by PA and the BRE.
The average PC consumes 800 kilowatt hours of energy a year and pumps out heat, which takes more than half as much energy again for the air conditioning system to remove.
The estimates of cost savings and some of the case studies in the Toolkit are based on the experiences of eight leading organisations that sponsored and tested the principles.
They were Anglian Water, the BBC, Honeywell, IBM, National Westminster Bank, P&O, the Prudential Corporation and the Royal Mail.
The Toolkit uses eco-points to grade the environmental impact of different activities, which means that managers can tell at a glance which actions have the biggest payback in environmental terms.
Although there is still debate over how many eco-points should be attributed to which activities, the points system is gaining acceptance among large European companies.
"Without such a system, environmental campaigns tend to be picked at random, regardless of their impact on the environment," says Tony Bishop, environment services manager for PA.
"Companies should not be directing office managers to put in plastic- cup recycling schemes when there are more important things to do."