The Construction Quality Assessment System (CONQUAS®), introduced in Singapore since 1989, serves as a national standard for assessing the construction workmanship quality of building projects.

CONQUAS® was designed with three objectives:

  1. To have a standard construction workmanship quality assessment system for building projects
  2. To make construction workmanship quality assessment objective by measuring constructed works against workmanship standards and specification, and using a sampling approach to suitably represent the whole project
  3. To enable construction workmanship quality assessment to be carried out systematically, within reasonable cost and time

Today, CONQUAS® is a widely recognised and internationally accepted benchmarking tool for quality. CONQUAS® is a registered trademark in Singapore, Malaysia, China, Hong Kong SAR, United Kingdom, Australia, South Africa and India.

Amendments to CONQUAS®

CONQUAS® is periodically fine-tuned to keep pace with changes in technology and quality demands of our population:

  • CONQUAS® 21– Launched in 1998 to introduce new features and refinements to make CONQUAS® scoring more comprehensive.
  • CONQUAS® 9th Edition– Launched in November 2017 to promote the adoption of Design for Manufacturing and Assembly (DfMA) which supports both high quality and productivity, and to ensure the score commensurate with end users’ expectations on workmanship quality.
  • CONQUAS® 2022 – launched in May 2022 and further enhanced in May 2023, to encourage developers and builders of building projects to take ownership of their construction workmanship quality while balancing Quality and Productivity. The key changes in CONQUAS® 2022 (applicable to private residential projects only, unless otherwise stated) are:

A. Removal of Bonus Points (BP) component (applicable to all project types);

B. Adjustment to the weightages for internal finishes to commensurate with end users’ expectations on quality;

C. Introduction of additional verification and functional tests, namely:

i. Water Flow Test (on sampling basis) for dwelling unit corridor, lift lobbies, footpath, exposed walkway in carpark and basement carpark to address issues of ponding at common areas; and
ii. Heat soak test for tempered glass to address issues of shattered glass within dwelling units and common areas

D. Streamlining of existing functional testing requirements:

i. Implementation of Self-Test (based on project QP’s declaration of the self-test
results) in place of actual test for Internal Wall Tiles Pull-Off Test

E. Added assessment of suspended swimming pool soffit for signs of water leakages.


  • The 3-tier CONQUAS® Scheme will apply to all CONQUAS® applications for private residential projects received on and after 9 October 2019.
  • The scheme aims to help developers/contractors further raise the quality of their projects by covering more samples and identifying more areas for improvement. 
  • The scheme is further reviewed to include escalation of CONQUAS® tier of ongoing CONQUAS® private residential projects after CONQUAS® application is made [see (a)iv in table below]. This is applicable to private residential projects with construction tenders called from 1 June 2022 and applied for CONQUAS® on and after 1 November 2022.

The revised tiering requirements as detailed in the table below:
Tier 3
1 Additional samples will be taken on: architectural internal finishes samples, wet areas water tightness tests for toilets/bathrooms and window water tightness tests.
2 100% checks refer to all location within all dwelling units in a project will be checked. Projects will be required to meet at least prevailing CONQUAS® band 2.
3 The initial CONQUAS® band will be derived after 20% (for tier 2a) and 50% (for tier 2b) of the required architectural internal finishes samples are completed.
4 Major defects refer to defects that would generally not be acceptable to end-users as specified in "Construction Quality Assessment System (CONQUAS®)" manual available on BCA's website.
5 Projects will be escalated one tier up from prevailing tier imposed.

      a. Private residential developments include private mixed developments with residential component 

How Do Companies Benefit

By submitting their projects for CONQUAS® assessment, companies can benefit from:

  • Benchmarking of its construction workmanship quality against CONQUAS® standards;
  • Increased client confidence and competitive edge when you consistently deliver projects with high CONQUAS® bands; and
  • Better marketability and enhanced corporate image with a good CONQUAS® track record

Assessment Approach

The assessment is divided into 3 main components (applicable to projects with construction tender calling date from 1 July 2023 onwards):

  1. Internal Finishes – mainly refer to architectural finishes (e.g. floors, internal walls, ceiling, doors, windows and components) and basic Mechanical & Electrical (M&E) fittings
  2. Installation Methods Verification and Functional Tests – applicable on the following 4 trades:
    • Waterproofing works to bathrooms/toilets;
    • Stone/tiling installation works;
    • Timber floor installation; and
    • Window installation
  3. External Finishes – roofs, external walls and external works at the completion stage of the building 

Each component is further divided into different items for assessment. The sum of the 3 components will give the CONQUAS® score used to derive the CONQUAS® band for the project.

Weightages – Weightages for the above components are allocated based on the building type (e.g. private residential, public residential, non-residential)

Site inspection – Buildings are assessed primarily through site inspection. The assessment is done throughout the construction process for Structural and M&E Works and on the completed building for Internal Finishes and External Finishes. The assessment also includes tests on the materials and the functional performance of selected services and installation; this helps to safeguard the interest of building occupants in relation to liveability and functionality of the architectural, mechanical and/or electrical components.

Sampling – As it is impractical to assess all elements, CONQUAS® uses a sampling approach which is based on the size of the building. The samples shall be distributed as uniformly as possible throughout the construction stages.

Scoring – The scoring will be done on the works that are inspected for the first time. Rectification and correction carried out after the assessment will not be re-scored. The objective of this practice is to encourage "doing things right the first time".


The manual provides detailed information on the assessment, including:

  1. The components to be assessed and their weightages according to the building type
  2. Assessment approach for each component
  3. Construction Workmanship Quality Standards: List of elements that will be assessed

Download the CONQUAS 2022 Manual (PDF, 1.0MB)
Download the CONQUAS 2019 Manual (PDF, 1.0MB)
Download the CONQUAS Manual - 9th Edition (PDF, 1.0MB)

How To Apply

View application procedures

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