Garden offices' carbon footprint

An interesting short piece by Lynn Fotheringham from Inside Out Buildings here on garden offices and carbon footprints. "Garden offices and other garden buildings can be as highly insulated as a new house to reduce their carbon footprint," she writes and draws up a simple checklist for those concerned about the issue including:
1. Have you got building regulation levels of insulation in your garden office to help balance your carbon footprint?
2. Has your garden office got double glazing?
3. When choosing new garden office equipment ask for an energy rating and don't leave any electrical equipment on stand-by.
4. Energy saving light bulbs.
5. Have the building materials in your new garden office been manufactured in the UK to reduce carbon miles and do the manufacturers care about their carbon footprint? Do they recycle. How do they fuel their manufacturing plant?