Following are some changes and modifications that you can bring about to reduce carbon footprint:

Lighting
•    Use higher efficiency fluorescent lighting.
•    Use light sensors to turn the lights off automatically where/when the office is empty.

Heating, Ventilating and Air Conditioning
•    Programme the heating and cooling systems for optimum temperature.
•    Set the temperature a couple of degrees higher or lower, depending on the season.
•    Switch off the system during non-peak hours.
•    Try to use natural ventilation and heating.
•    Clean air filters and tune the system annually by a licensed contractor.
•    Replace old equipment with a more efficient system.

Office space planning
•    Redesign your office to make the most efficient use of space

Reduce, Recycle and Reuse
•    Separate bins for recycling cardboard, cans, paper and bottles.
•    Send notices via email or post them in a common area instead of printing individual copies.
•    Thoroughly edit all documents before printing.
•    Space efficient formats for letters, documents and memos will reduce paper usage.
•    Use printers that can print on both sides of the sheet.
•    Use dishes and utensils instead of paper plates and plastic cutlery.
•    Use an office design company such as Space Planning UK to redesign your office space by reusing your existing office furniture rather than just rushing out to buy new

The expense records and utility bills will provide an accurate record of the spending on water, electricity, and office supplies. This data will help in effecting necessary improvements for reducing the carbon footprint of an office.