من أين يأتي توفير الطاقة بنسبة 40% فعلياً

A 40% reduction is achievable. It is also frequently quoted without saying against what baseline, which makes it meaningless.

The breakdown

On the villa and apartment projects we have metered, cooling dominates — typically 60 to 70% of consumption. Lighting is a distant second. Any saving figure that does not start with HVAC scheduling is not a serious figure.

• Occupancy-driven HVAC setback: the single largest measure
• Zoned scheduling instead of whole-property setpoints
• Daylight-linked dimming, which matters more in offices than homes
• Standby elimination on AV and kitchen circuits

What the number depends on

The baseline. A property previously running fixed 21°C around the clock will show a dramatic improvement. A well-operated building with a disciplined facilities team will show far less, and honest reporting says so.