RIAI Guidance: Ancillary Certification - Specialist Subcontractor with design responsibility
Since the introduction of Building Control Amendment Regulation (BC(A)R legislation in 2014, architects have been central its implementation, providing design and assigned certifier services, generally acting as lead consultant administering the building contract.
The BC(A)R legislation and process is principally about construction quality. The RIAI will shortly publish its review of BC(A)R and the statutory Code of Practice for Inspecting and Certifying Buildings and Works 2016 (Code of Practice). The RIAI believes that it is important that all parties to the BC(A)R process review its implementation and provide updated guidance as necessary to their respective members and to DHLGH.
Ancillary certification is a critical component of BC(A)R for both design and its implementation in construction. The RIAI participated in the publication of general industry guidance on the provision of ancillary certification in Practice Note 1 of 2014, which states that its templated forms of certification cannot be altered without the collective approval of all organisations who agreed to the wording.
The RIAI published guidance to its members in the form of the RIAI BC(A)R Code of Good Practice for Designer and Certifier Roles in 2015 and revised in 2020. This guidance relied on the implementation of Practice Note 1.
The CIF, as the representative body for builders certifying compliance on completion, published advice to members in 2022 and again in May 2025 calling into question the application of Practice Note 1 in ancillary certification by specialist subcontractors with a design responsibility. This resulted in their current guidance to CIF members that “builders, subcontractors, and the specialist designers should only provide a Cs and/or a CSS certificate”. This 2025 guidance amends the 2022 advice and is causing significant uncertainty in the BC(A)R process particularly at project completion stage. The 2025 CIF advice is that subcontractors cannot sign a Practice Note 1 design certificate in its fixed templated form. This may be a misrepresentation of their BC(A)R participation. Any specialist design responsibility transferred to the builder under contract must be included at tender stage.
While Practice Note 1 does not provide for contractor or sub-contractor design certification, with necessary inspection and certification on completion post commencement, it has become custom and practice since 2014 for ancillary certifiers to amend the templated Practice Note 1, to reflect competence and responsibility in certification and to address this certification gap.
Proposed Amendment to Practice Note 1
The RIAI propose that Practice Note 1 be amended to acknowledge that the existing templated certification has limitations in not providing for design certification post commencement and to:
- Advise that contractor design responsibility and related ancillary certification should be agreed at tender stage for incorporation into contract.
- Include an additional Practice Note 1 templated form of specialist subcontractor ancillary certification.
The intention in proposing the development of an additional form of certification is to preserve the integrity of the existing certification and to clearly identify and provide for the specialist design input, which can take place before or after commencement.
Download the template Specialist Subcontractor Ancillary Certification Form for addition to the existing Practice Note 1 suite of ancillary certification.
This draft template has been accepted in practice and subjected to legal review by construction lawyers. Their advice is that amendment to Practice Note 1 certification is possible and that the priority is for certification to accurately reflect the participation and responsibility of the certifier.
The draft recognises the responsibility of the builder to facilitate inspection planning and provides for the specialist subcontractor to prepare an appropriate inspection ‘regime’ for implementation by both builder and assigned certifier as necessary.
The RIAI are discussing the potential review of Practice Note 1 with the ACEI, SCSI and EI with a view to a resolution of the current gaps in certification that impact on the design certifier and ancillary certifier’s ability to provide appropriate certification to the assigned certifier. The ACEI has recently published guidance to its membership relating to Practice Note 2 (Pre-Cast Concrete design), amendments to Sd and Sc certification and advising that where a member accepts a Cs CIF-01 ancillary certificate covering subcontractor design, that Annex Schedule 2 of the certificate must include details of the scope of the design and its supporting documentation.
In the interim, RIAI members should consider the use of the proposed additional RIAI specialist subcontractor certification suite, appropriate amendment of Practice Note 1 S-suite or other form of ancillary certification that addresses the specialist subcontractors design scope, certifies design compliance, adherence to the Code of Practice the maintenance of PI insurance and the provision of an appropriate inspection regime to the assigned certifier for their element of work.
Rationale for Amendment to Practice Note 1
Summary
The substantive issue here is the ‘industry’ agreed non-statutory forms of ancillary certification as set out in Practice Note 1. The templated certification for use by designers implies that only designers who exist at commencement stage can provide the certification. It is recognised that design, particularly specialist design (including that by contractors) also takes place post commencement.
This is acknowledged and provided for in the Code of Practice which states that “Design work that is due for completion and specialist design that is not available for submission at commencement stage should be certified and submitted at a later stage”.
Analysis and Rationale
This guidance relates to ancillary certification under the Code of Practice and the building contract where design responsibility is transferred from the employer to the contractor for parts of the works within a traditional ‘employer designed’ contract.
The BC(A)R commencement under S.I.9 2014 states the following:
These Regulations strengthen the current arrangements in place for the control of building activity by requiring greater accountability in relation to compliance with Building Regulations in the form of statutory certification of design and construction, lodgement of compliance documentation, mandatory inspections during construction and validation and registration of certificates.
The Code of Practice does not prohibit the ‘use of other suitable frameworks or approaches’ and encourages all parties to ‘achieve good outcomes’. The Code of Practice states that the ‘overall objective of the revised building control system is to achieve better building construction’, and that ‘the purpose of the Code of Practice is to provide guidance with respect to inspecting and certifying works or a building for compliance with etc…the Building Regulations’.
The Code of Practice states that inspection and certification in accordance with its guidance provides prima facie indication of compliance with the relevant requirements of the Building Control Regulations.
The Code of Practice requires interpretation and judgement in the areas of design responsibility and ancillary certification. This will be determined by a risk assessment based on including types of building type and construction methodology, builder expertise, design complexity and experience in the management of inspection and certification.
Design Responsibility
Design, for the purpose of construction, is defined in the Building Control Act 1990 and Safety Health and Welfare at Work (Construction) Regulations 2013.
The principles of design responsibility and construction stage inspection by designers are set out in the Code of Practice. All designers (consulting architects or engineers, specialists, contractors and others and must take responsibility for their design and its implementation in construction. The Code of Practice requires that designers provide appropriate ancillary certificates when required by the assigned certifier and design certifier.
The certification of design work that is due for completion and specialist design that is not available for submission at commencement stage is referred to in Sections 4.3 and 5.3 of the Code of Practice and provided for in Part A of the statutory form of Certificate of Compliance on Completion. All design, irrespective of when it takes place, must be appropriately certified.
Building Contracts
Some commercial building contracts are drafted as amended RIAI Contract (Yellow/Blue) forms. These amendments include an allocation of design responsibility to the contractor in the articles of agreement and/or conditions of contract. Most commonly it is set out under Clause 2 - Scope of Contract (2017 edition) together with a full deletion and amendment of Clauses 16/17, eliminating the Nominated Sub-Contractor and Supplier, and creating a ‘specialist’ domestic sub-contractor.
These amended RIAI contracts normally set out specific responsibility and obligations for the contractor relating to design. They usually do so in designating contractor designed elements of work to be carried out by (scheduled) specialist or key sub-contractors. The contractor/specialist is required to have competence, experience etc., and to apply the usual standard of skill, care and diligence in carrying out the design of these scheduled work elements. The contractor is required to enter into a sub-contract with the specialist and provide an assignable collateral warranty on this for the benefit of the employer. Professional indemnity insurance (PII) cover level is specified in the subcontract and collateral warranty.
Amended contracts often include a general contractor obligation to cooperate with and provide information to the assigned certifier for the purpose of Building Regulation compliance. However, the type and format of sub-contractor design ancillary certification for BC(A)R compliance is often not specified or attached.
The type and format of this non-statutory ancillary certification can vary over time (industry interpretation) and should be determined on a project-by-project basis by the design certifier and employer designers and communicated to the contractor at tender stage.
Change in contract scope, where contractors are encouraged to innovate and value engineer, or where they may propose substitution of design, can result in conflicting interpretation of design responsibility and attendant certification obligations. If a design responsibility is not clearly transferred to the contractor at tender or contract stage it may lead to a claim for variation. A contractor-led change or substitution does not automatically trigger such a claim, but it can still alter the planned BC(A)R certification responsibility. Therefore, any such change should not be approved without the confirmation that it does not involve certification responsibilities.
The scope of contractor design will vary from project to project. Contractor design through sub-contract with specialists typically include the following activities:
- Piling
- Specialist waterproofing / tanking
- Precast concrete structure (loadbearing/stability-complex assembly only)
- Post tensioned RC slabs
- Steel connections
- Secondary steel (depends on specified use, guardings, etc.)
- Light gauge steel internal/external wall (SFS type) systems
- Structural timber frame systems
- Flood protection systems
- Glazing /Curtain wall systems
- Stone/Concrete cladding systems
- Siphonic drainage systems
- Guardings
- Passenger Lifts
- Sprinkler systems
- Smoke extract ventilation
Allocation of Design Responsibility
The consultant architectural and engineering designers (ancillary certifiers) and Design Certifier should accept their design scope and responsibility and advise as to the elements of where they will rely on contractor/specialist design. They should identify what element(s) of their performance specified design relies on others in the context of the detailed design development and implementation on site. In doing so, they should confirm the form of certification necessary to support their own A, E or S ancillary certification, i.e., S-suite or Cs/CIF-01. This will depend on the extent of specialist design, sub-specialists design, proprietary design and contract context.
This contractor/specialist design should be incorporated into tender and contract documents. The contractor ancillary certification should be agreed between the assigned certifier and builder prior to commencement.
In these cases, the identified sub-contractor specialists are designers and become ancillary certifiers, providing appropriate certification identifying the scope and extent of their design. As design ancillary certifiers, they are bound by the Code of Practice, with designer responsibilities as set out in Section 3.4 Designer’s Role.
The certification by consultant designers and contractor specialist sub-contractors should accurately reflect their role and design activity. In the case of the specialist sub-contractor, this would state the extent of their design as set out in their sub-contracted scope based on the employer’s performance specification. This clarity is necessary for BC(A)R compliance but also for the individual designers PII insurance cover, the benefit of which is assigned to the employer through appointment contracts, building contract, sub-contracts, and collateral warranties over same.
Contract and Design Ancillary Certification – Practice Note 1
The necessary process of the coordination of post-commencement design and its certification is not reflected in ‘industry’ Practice Note 1. Practice Note 1 is a non-statutory industry guidance/advice note. It must be interpreted with reference to the statutory Code of Practice.
The use of Practice Note 1 S/E-suite certification by specialist sub-contractors has been common practice in interpretation and implementation of the Code of Practice since its publication in 2014. Owner/Developers, Builders and Designers are not limited by Practice Note 1, which represents a minimum standard for industry practice.
The Practice Note 1 A, E and S eight-part certification is made with specific reference to the Code of Practice, confirms that the designer holds PI insurance, sets out design scope and certifies design and implementation of design compliance based on inspection. The Cs/CIF-01 three-part certification does not refer to the Code of Practice (other than with reference to maintaining records), PI insurance, design compliance or inspection of the implementation of design. Page 2, Annex 2 of the Cs certificate refers to ‘associated design’, which could suggest that the principal and responsible designer for the element is the person or persons who provided the drawings, calculations, and specification schedules listed in Annex 1. This interpretation creates uncertainty about who holds design responsibility. The ACEI’s recent analysis in Practice Note 2 highlights this issue and calls for greater clarity.
The sub-contractor ancillary certifiers identified are designers, with obligations to design, inspect, certify and provide PI insurance under the Code of Practice. Where there is a specialist subcontractor undertakes significant design, it is normal that they would certify the compliance of this design and provide appropriate PI insurance, as required by the Code of Practice.
Where a consultant architectural or engineering designer (ancillary certifier) transfers part design responsibility in a performance specification to a specialist sub-contractor they will be certifying the compliance of this specialist design in their ancillary certificate in the absence of appropriate specialist certification.
The present divergence of opinion relates to the templated form of certification published in Practice Note 1. The A, E and S design certification wording is such that it implies that it can only be used by a designer who provided design at pre-commencement stage. Based on this wording, the deduction is that this cannot be the contractor/specialist unless they were party to the design certification. Relying on general industry guidance to interpret and apply the Code of Practice is not a definitive basis for interpreting contracts. This is especially true when such guidance may change over time, making it unreliable for ensuring compliance with the Building Regulations and the Code of Practice.
DISCLAIMER
Please note that this advice note is provided for general information and guidance only and does not constitute legal, professional, or technical advice. While every effort has been made to ensure its accuracy at the date of publication, the RIAI accepts no responsibility or liability for any loss or damage arising from reliance on its contents. Readers should seek independent professional, legal and/or professional advice appropriate to their specific circumstances.