Design HDB flats such that households can save energy

The report “HDB seeking to channel sunlight into basements” (Oct 27) stated that the Housing and Development Board (HDB) is seeking to use sunlight as a lighting or energy source, with the objective of slashing energy costs by half.

To reduce energy consumption, it must also look at wind flow and ventilation in its flats, as air-conditioners and cooling appliances take up a huge proportion of household electricity bills.

Many new HDB flat designs do little to reflect our tropical climate: Ceilings are low, units are small, many units face the setting or rising sun and many rooms have full-length windows. The last two factors combine to cause a greenhouse effect.

My five-room flat has two bedrooms with normal two-pane windows and one bedroom with full-length windows. All three get the morning sun.

There is a significant difference in temperature between the first two and the last room in the late morning and on bright, warm days. The latter room almost always needs air-conditioning to lower the temperature to a comfortable level.

The HDB should consider these points when designing its flats.