SINGAPORE - Water ponding in common areas, sudden shattering of glass and leakage from swimming pools will soon be included in assessments of private residential construction projects.

These checks will be added to the Construction Quality Assessment System, or Conquas, that was introduced in 1989.

It will see its 11th edition - Conquas 2022 - take effect for private housing projects with construction tenders called from June 1.

Conquas assessments have been required for new buildings constructed on Government Land Sales sites since 1992, and public-sector building projects with contract values above $5 million since 1998.

Announcing the revised Conquas scheme on Friday (May 6), Minister of State for National Development Tan Kiat How said the enhancements factor in feedback from residents between 2018 and 2020.

Such feedback helped to identify issues that have yet to be captured in older editions of Conquas, said Mr Tan, who cited issues such as the quality of construction materials or poor workmanship in common areas, which could lead to water ponding.

A Building and Construction Authority (BCA) spokesman said that between 2018 and 2020, BCA received feedback on issues relating to water ponding, water seepage and glass shattering from about 140 dwelling units per year. 

Speaking at a quality and productivity seminar organised by BCA and the Real Estate Developers' Association of Singapore (Redas), Mr Tan added that the new assessment checks will minimise safety and liveability issues that home owners face.

For instance, he said, spontaneous glass shattering can cause injuries. Conquas 2022 will include heat stress tests for glass used in balconies or showers.

The new assessment criteria also requires project teams to provide a three-year warranty for such materials.

Water ponding in common areas will also be assessed under the revised framework. Water flow tests will be run in areas such as corridors, lift lobbies, walkways and basement carparks.

Mr Tan Boon Kee, principal quality specialist in BCA's quality and certification department, said ponding may occur due to choked or improperly constructed drains, as well as insufficient gradient, which retains water instead of allowing it to flow away. This creates slipping hazards and hygiene issues, he added.

Checks on water seepage in common areas will also be conducted to reduce slipping hazards. This will include swimming pools that are suspended over basement carparks.

Asked why the expanded scope of assessments applies only to private residential projects, the BCA spokesman said that the Housing Board  already has a rigorous checking system for public housing projects.

He also added that  the extent of finishing provided can be quite different for public and private residential projects. 

On Friday, Mr Tan Kiat How also announced that a new Conquas banding system is in the pipeline, to help users better differentiate the relative performance of construction projects.

Noting that more than 90 per cent of recent private residential projects have bagged more than 80 out of a maximum score of 100 points in Conquas assessments, he said it may be difficult for home buyers to discern the differences between projects by raw scores alone.

He added that changes to the banding system will also see developers and builders - not just their construction projects - banded. These bands will be decided based on factors such as track records and valid public feedback.

BCA said in a circular to the built environment industry that the banding can contribute to the branding for developers, especially those which have consistently shown good workmanship, been responsive to feedback, and rectified defects.

Redas president Chia Ngiang Hong said developers can also decide on builders to appoint for their projects based on the new banding system.

BCA said the Conquas adoption rate for private residential developments from 2019 to 2021 has been about 95 per cent, by dwelling units.

The BCA spokesman added that the Conquas assessments are done during construction and the scores are typically published a year after the Temporary Occupation Permit is issued.

He added that this allows the assessment to factor in homeowner feedback on major defects - if any - during the  Defects Liability Period, which  typically lasts for 12 months.