https://www.iras.gov.sg/irashome/upl...ndividuals.pdf
just to put the 2 points together:
5 Tax Change with effect from YA 2016
5.1 To simplify tax filing and ease the burden of record keeping for taxpayers, it
was announced in the Budget 2015 that with effect from YA 2016, an
individual may opt on a yearly basis to deduct an amount of deemed
expenses, in lieu of the actual amount of deductible expenses incurred,
against his passive rental income from the letting of a residential property in
Singapore. An individual who has claimed an amount of deemed expenses
against his rental income can in addition, make a claim for deduction on
allowable interest expenses, if any.
5.2 The amount of deemed expenses allowable in respect of a residential
property is 15% of the gross rental income. This amount of deemed
expenses is considered to be generally in line with the amount of common
rental expenses (such as property tax, property maintenance fees and
minor repairs) that a landlord will incur.