PBU Performance Requirement
What is a Prefabricated Bathroom Unit (PBU)?
A prefabricated bathroom unit refers to a bathroom unit preassembled off-site complete with finishes, sanitary wares, concealed pipes, conduits, ceiling, bathroom cabinets, shower screen and fittings before installing in position.
What are the benefits of using PBUs?
By shifting most of the fabrication work and wet trades off-site to the controlled environment of a factory, PBUs can yield both time and manpower savings by about 60%. Downtime can be minimised as production of PBUs can continue even during times of inclement weather. Furthermore, there is a better control of both materials and the prefabrication process, resulting in higher quality finishes and lesser wastage.
Mandated Use of Prefabricated Bathroom Unit (PBU)
The use of prefabricated bathroom unit (PBU) is mandatory for all non-landed residential Government Land Sale (GLS) sites from 1 Nov 2014 onwards. Further details on the mandatory requirement are stipulated in the Code of Practice on Buildability 2014. You may find out more information about this mandatory requirement through the following circular issued on 1 Nov 2014.
|Fig 1 Concrete PBU||Fig 2 Metal Frame PBU with Drywall Panels|
Prefabricated Bathroom Unit (PBU) Acceptance Framework
PBU designs have evolved over the years and may also involve the use of alternative materials in its fabrication. To ensure that the different PBU systems being used at the mandated development sites are reliable and durable, BCA has set up an acceptance framework consisting of building regulatory agencies as well as industry experts to ensure that the design and materials used are robust and can meet the minimum standards set.
Under the PBU acceptance framework, PBU suppliers and manufacturers who intend to supply their PBU systems to be used at development sites where PBU is mandated must first ensure that their PBU system can meet the PBU performance requirement. The proposed PBU systems will also be subjected to the evaluation and acceptance of the Building Innovation Panel (BIP).
There are two separate evaluation stages under the BIP for PBU systems. Stage 1 consists of a PBU Screening Panel chaired by BCA and other industry representatives, who will evaluate the design and materials used. Once the PBU system is accepted by the PBU Screening Panel, the BIP Secretariat will then assist and coordinate submissions to the remaining regulatory agencies under the BIP and facilitate early resolution of outstanding issues between the applicant and the respective agencies (Stage 2).
A letter of In Principle Acceptance (IPA) will be granted if acceptances are obtained from both the PBU Screening Panel (Stage 1) and the relevant participating regulatory agencies (Stage 2) under the BIP. The accepted PBU systems are listed below (refer to Table 1).
PBU Manufacturer Accreditation Scheme (PBU MAS)
The manufacturer of the PBU system will need to apply for the accreditation under the PBU Manufacturer Accreditation Scheme (PBU MAS) after obtaining IPA from BIP. PBU manufacturers will be accredited at the firm level. However, if the manufacturer is using an existing construction site as a temporary production facility to carry out finishing and fitting works for the PBU, such a temporary production facility will also require accreditation. Moreover, when the temporary production facility is moved to a different site, the manufacturer is required to re-apply for the accreditation again. Manufacturers who have obtained the IPA (from BIP) and are accredited (by the PBU MAS) shall be responsible for the quality and productivity of the PBU production. In addition, they shall also be ready to provide advice to homeowners with regards to the maintenance of the PBU.
PBU suppliers/manufacturers who have successfully obtained the IPA are reminded to apply for the PBU MAS as soon as possible due to the lead time required. The accreditation process under the PBU MAS may take up to 6 months if the production facilities do not meet the relevant requirements under the accreditation scheme.
For projects where the adoption of PBUs is mandatory, PBU suppliers are reminded to apply for and clear at least Part 1: Documentation Audit of the PBU MAS before commencing production works at the factory.
Fig 3: Acceptance Framework Flowchart
Please send in your application with the following documents:
- A completed and duly signed application form
- Completed checklist, Appendix A and B
- Presentation slides on the proposed PBU system (you may refer to the sample template for the recommended presentation flow and content)
- Additional supporting documents (e.g. material or product specification, quality certifications or test reports by accredited laboratories etc)
- A set of drawings of your proposed PBU system as per the requirements in the Table Reference and suggested template
- Test reports for boards used as wall and floor of PBUs (please refer to Appendix C for the list of test methods required)
- Test reports for lightweight concrete panels used as wall and floor of PBUs (please refer to Appendix D for the list of test methods required, with IPA dated on or after 1 Jan 2017 onwards.)
- Any other relevant information
For item (b), please ensure that the presentation slides cover all the necessary content as per the checklist in item (a). The presentation content should also show that the
proposed PBU system can meet all the PBU performance requirement. Please note that the applicant can only go for presentation to the PBU screening panel upon completion of item (a), (b) and (d).
Applications to the PBU Screening Panel under the BIP can be sent to:
Ms Go Hui Jing (firstname.lastname@example.org)
Mr Lucas Loke (email@example.com)
In-Built Bathrooms for Prefabricated Prefinished Volumetric Construction (PPVC)
Suppliers who intend to manufacture and supply PPVC modules should take note that the in-built bathroom within the PPVC module must comply with the PBU Performance Requirement as well. The accepted in-built bathroom systems are listed in Table 2 below.
List of PBU suppliers that meet the Performance Requirement
The list of PBU systems which meet the performance requirement and their respective supplier and/or manufacturer can be found here.
The list of In Principle Acceptances (IPA) granted are listed below. Please take note that some suppliers IPAs are still pending and thus will not be listed in the table below.
Table 1 Accepted PBU Systems
Note 1Drawings of PBU design will be made available.
Note 2The performance achieved by the lightweight concrete / non-concrete wall panels of this PBU system according to SS492 Specification for performance requirements for strength and robustness (including methods of test) for partition walls was based on a wall junction assembly with either more than one right-angle corner or via a volumetric setup, which was improvised from the original specifications of SS492.
NOTE: The above publishing of PBU suppliers is solely for the purpose of sharing of information to facilitate the industry users to source for such products. It is NOT an endorsement of these products by BCA nor does BCA give any warranties, explicit or implied, regarding the availability of the products, information, product or services, efficacy of the products or warranties of merchantability, fitness for a particular purpose, title or non-infringement. The supplier/user must ensure that their products are safe for public use and comply with all relevant regulations and statutory requirements at all times
The In Principle Acceptance (IPA) of the following PBU supplier is suspended for non-compliance with the performance requirements and acceptance framework under the Code of Practice on Buildability. With immediate effect, the PBUs provided by the supplier cannot be implemented at any new building development until further notice.
|PBU Supplier||BIP Reference Number||PBU Type|
|Hong Xing Engineering & Construction Pte. Ltd.||BIP IPA 2015-08-0028||Drywall PBU|
Table 2 PBU Supplier(s) with IPA(s) suspended
List of PPVC suppliers for In-Built Bathroom that meet the Performance Requirement
|PPVC Supplier||In-Principle Acceptance (IPA)||In-Built Bathroom DrawingsNote 3|
|Moderna Homes Pte Ltd||BIP2012-12-0005IBB||Sample Drawing|
|Excel Precast Pte Ltd||BIP2016-01-0034IBB||Sample Drawing|
|Dragages Singapore Pte Ltd||BIP2016-01-0036IBB||Sample Drawing|
|Dragages Singapore Pte Ltd||BIP2016-05-0046IBB||Sample Drawing|
|SPP System Pte. Ltd.||BIP2016-01-0035IBB||Sample Drawing|
|Integrated Precast Solutions Pte. Ltd.||BIP2016-04-0039IBB||Sample Drawing|
|Quicksmart Technology (Singapore) Pte. Ltd.||BIP2016-05-0040IBB||Sample Drawing|
|iMax Modular Pte Ltd||BIP2016-05-0041IBB||Sample Drawing|
|Vico Construction Pte. Ltd.||BIP2016-05-0042IBB||Sample Drawing|
|CS Corp Pte. Ltd.||BIP2016-09-0048IBB||Sample Drawing|
|Mod Prefab Private Limited||BIP2016-09-0049IBB||Sample Drawing|
|Qingjian International (South Pacific) Group Development Co., Pte. Ltd.||BIP2016-09-0052IBB||Sample Drawing|
|Tiong Seng Contractors Pte Ltd||BIP2015-10-0050IBB||Sample Drawing|
|TK Modular Pte Ltd||BIP2017-08-0071IBB||Sample Drawing|
|HL Building Material Pte Ltd||BIP2016-09-0050IBB||Sample Drawing|
Table 3 Accepted In-Built Bathroom systems
Note 3 The drawings in Table 1 and 3 are intended to provide a guide for the basic design concept of the PBU systems or in-built bathrooms evaluated by the Building Innovation Panel (BIP). This is for the reference of the industry only. The Qualified Person (QP) is to ensure that the PBU systems used shall comply with the performance requirements as set out in the relevant issue of Code of Practice on Buildability to be used for the respective project. He has to ensure that all aspects of the PBU systems used shall be suitable and reasonably fit for the purposes for which they are required.
List of drywall systems allowed for use in PBU systems
A drywall system generally comprises panel board(s) fixed on each side of the framing system e.g. studs, tracks and joint materials, infill with insulation.
There are different types of drywall systems available in the market that offer a wide range of impact strength, fire resistance, acoustic ratings, and moisture resistance to meet design requirements. It is critical to ensure that the drywall system and/or panel board(s) used for the floors and walls of bathrooms are durable in wet areas in order to safeguard the interests of homeowners.
Under the Building Innovation Panel of the PBU Acceptance Framework, the type of drywall system including its brand/model and thickness of board used in the PBU system or in-built bathroom is required to meet the following criteria:
- The drywall system shall achieve a minimum grade of Medium Duty in the test methods in accordance with the SS492.
- The respective panel board used shall comply fully with the passing criteria of the prevailing test standards as listed on Appendix C: Test Reports for Panel Boards Used as Wall and Floor of PBUs.
Till date, the following panel boards as listed in Table 4 have been tested to the 13 standards listed in Appendix C. Please refer to their respective test report for SS492 to find out the acceptable framing system for each drywall system.
|Panel Board||Test Report for Reference of Acceptable Framing System
(Please obtain the test reports from the respective supplier.)
| Minimum 12.7 mm thick Concritboard pre-treated with cementitious waterproofing membrane
(Fibre-cement board of density
|Test report no. 54S074470/1/TWL dated 20 Aug 2007 issued by PSB Corporation|
| Minimum 12.7 mm thick Durock Next Gen
(Fibre-cement board of density
|Test report no. 7191127431/03-MEC15-YX dated 22 March 2016 issued by TUV SUD PSB Singapore|
| Minimum 12 mm thick James Hardie Villaboard
(Fibre-cement board of density
|Test report no. 7191124970-MEC15/05-YX dated 07 December 2015 issued by TUV SUD PSB Singapore|
| Minimum 8 mm thick Kalsi board
(Fibre-cement board of density
|Test Report No. 7191068144-MEC13-YX dated 09 September 2013 issued by TUV SUD PSB Singapore|
| Minimum 8 mm thick Shera board
(Fibre-cement board of density
|Test Report No. 7191031976-MEC12-YX dated 14 June 2012 issued by TUV SUD PSB Singapore|
Table 4 Panel boards that meet the passing criteria of the test standards as listed on Appendix C
The Qualified Person (QP) shall take all reasonable steps and exercise due diligence to ensure that the drywall system and/or any panel board(s) used in the PBUs or in-built bathrooms installed in the project meet the following minimum requirements:
- The details of the drywall system shall be in accordance with those accepted by the Building Innovation Panel (BIP) and granted with the In-Principle Acceptance (IPA) for each respective PBU supplier.
- The drywall system and the respective panel board used shall comply fully with the passing criteria of the prevailing test standards as listed on Appendix C: Test Reports for Panel Boards Used as Wall and Floor of PBUs.
- The PBUs installed in the project shall comprise panel boards with the same brand name and thickness as specified in the In Principle Acceptance (IPA) letter and/or drawings of each respective PBU supplier. Both IPA letter and drawings can be found in Table 1 and 3 of the BCA website.
- Any materials used for the finishes (such as waterproofing system, tile adhesive, tiles, etc.) of the PBU wall are compatible with the drywall system.
- Where the materials, dimensions and configuration of the framing system or part thereof of the drywall system are different from those as tested for the acceptable test reports as listed in Table 4, the QP shall ensure that either of the following is satisfied:
- The drywall system is tested in accordance with SS492 and achieves a minimum grade of Medium Duty; or
- A Professional Engineer (PE) registered under the Professional Engineers Board, Singapore, provides calculations and endorsement to show that the different framing system of the drywall system is equivalent or better in terms of structural performance as compared to the tested system
- A PE designs and endorses the necessary supports and reinforcement to the drywall system for the installation of fixtures and future provision of grab bars in compliance with the Code of Barrier-Free Accessibility in Buildings.
- All metal components in the drywall system shall be of suitable materials resistant to and suitably protected against corrosion over a long period of time, such as hot-dipped galvanised steel and zinc/aluminium alloy-coated steel.
- Precautions to prevent electrolytic corrosion are taken where dissimilar metals of the drywall systems are in contact.
None of the panel board's part, mixture, chemical constituents, brands/model, and /or plant location shall be changed.
The above listing is based on the submissions made to the Building Innovation Panel by PBU suppliers. BCA shall not entertain suppliers of drywall system and/or panel boards on requests to list products outside the submissions to the Building Innovation Panel.
NOTE: The above publishing of panel boards is solely for the purpose of sharing of information to facilitate the industry users to source for such products. It is NOT an endorsement of these products by BCA nor does BCA give any warranties, explicit or implied, regarding the availability of the products, information, product or services, efficacy of the products or warranties of merchantability, fitness for a particular purpose, title or non-infringement. The supplier/user must ensure that their products are safe for public use and comply with all relevant regulations and statutory requirements at all times
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