The Housing Board launched 3,139 new flats on Wednesday in the first Build-to-Order exercise of the year, which also marks the start of the gradual slowing of flat supply.

The flats are across five projects in four non-mature towns - Bukit Batok, Jurong West, Punggol and Woodlands - and another project in the mature town of Serangoon which has studio apartments only.

From this launch onwards, all new HDB developments will also include a standard suite of eco-features to manage water, energy and waste more efficiently. These include LED lighting with motion sensor controls, and centralised recycling chutes to promote recycling.

For the rest of the year, there will be "a good mix of BTO flat types across various towns", said the HDB. These include Bukit Batok, Hougang, Jurong West, Kallang Whampoa, Punggol, Sembawang, Sengkang, Tampines, Toa Payoh, Woodlands and Yishun. This is the first tranche of the 24,300 BTO flats to be launched this year, which includes 5,000 2-room flats - almost twice the number in 2013 - but fewer 3-room and larger flats than last year.