The consultation on the draft PAS 8700 (PAS), the specification for Modern Method of Construction (MMC) for new build residential properties, as drafted by the Ministry of Housing, Communities and Local Government (the Consultation), was published by the British Standards Institution on 22 October 2024.
The Consultation will remain open until 18 November 2024. Learn more.
The draft PAS specifies requirements for Design for Manufacture and Assembly (DfMA) and MMC in new build residential properties (excluding industrial and commercial buildings, hostels, care homes, hotels, prisons and hospitals). PAS specifies the requirements for individual elements and build types for the entire life cycle of a project, including disassembly and recycling. Whilst much of PAS is technical in nature, it does contain useful insights into the interplay of contractual considerations and procurement within the MMC sphere.
What is MMC and DfMA?
MMC covers any building methods which are designed to improve productivity and safety, while reducing the need for labour. It is a term that is often used to describe off site production of buildings (as this is a departure from traditional building methods, aimed at improving productivity and reducing labour requirements) but it encompasses any building method with the explicit objective of improving efficiency.
DfMA is a term that addresses two design considerations (i) how a component is manufactured; and (ii) how it is assembled. The latter is more complex than it may first seem, as the assembly of a component can be bespoke to varying degrees.
PAS and Implications for Contracts
Design
The PAS recommends that responsibility for design information and information release shall all be agreed at RIBA Stage 1. The designer identified should produce a performance specification for the MMC manufacturer who shall then provide design submissions demonstrating compliance with the employer's requirements.
Design Freezes are also implemented and all team members, including the Client, shall agree the point at which the design elements are to be fixed. The project programme shall incorporate Design Freeze milestone and pre-order dates and key aspects of the design shall be defined and fixed to allow for manufacturing.
Therefore, Clients must appoint designers and manufacturers at a much earlier stage than in the traditional design and planning process and use forms of contract which support early supplier involvement (ESI) as recommended by the Construction Playbook such as PPC 2000 and pre construction services agreements (PCSA's).
The PAS sets out a matrix of design responsibility across the professional team and recommends services specific to an MMC project for structural and fire engineers.
Fire and building safety is reflected throughout the PAS although no reference is made to co-ordinating with the Gateway stages under the Building (Higher-Risk Buildings Procedures) (England) Regulations 2023.
Funding
The PAS recognises that with MMC manufacturing processes, significant financial investment is required during the early stage of the project and therefore initial payments in the region of 50% of the total manufacturing cost are often required. While such a large, advanced payment presents risks for the Client (especially given the vulnerability of many manufacturers within the MMC sphere), some protection can be sought from escrow accounts, insurance bonds, letters of credit or advanced payment guarantees and use of Project Bank Accounts as recommended by the Construction Playbook should be considered.
The PAS recommends the appointment of an MMC adviser by the Client to bring technical skills and knowledge of MMC and also strategic oversight during the early stages of the project including expertise in relation to advanced payment mechanisms, as well as bonds and vesting processes. A detailed set of service requirements for the MMC adviser is set out in the PAS.
Quality
The PAS recommends that it should be the role of the MMC structural engineer to agree the codes and standards to undertake the project design works. The PAS does recognise that, for off-site manufacture, there is a need for both factory quality assurance, inspection and testing and on-site testing and commissioning.
It recommends that a factory production control (FPC) system shall be implemented to enable effective monitoring and checking of resource, process and outgoing products for quality and consistency. This shall include controls to monitor and check incoming resources; controls to monitor and check products during and post assembly (prior to delivery to site); intermediate testing to ensure declared performance and spec are continually met and procurement control e.g. approved suppliers.
Throughout the project there shall be documented evidence of an auditable system of quality management and assurance in place to govern the manufacture and production of systems, assemblies and components.
There are useful flow charts referencing the key handover points and construction interfaces and the PAS refers to the role of the latent defect insurers inspection team to test quality at key stages.
PAS 8700 and Procurement
The PAS provides an optimised process by relying on the correct approach to client project management, from setting initial client requirements, integrating the team with the appropriate procurement mechanism, and front-loading key decision-making in the pursuit avoiding unnecessary Client change.
The PAS envisions that the Client shall engage designers and other team members, including potential supply chain partners, to align with both strategic objectives and value-based decisions. The Client will also define designers and other team members scope and responsibilities, to align with the project programme requirements for the manufactured elements. The PAS dictates that the members of the project team shall have experience and knowledge of MMC and DfMA that is appropriate for the scope and complexity of the project or programme.
However, aside from a mention in the checklist triggering Clients to remember that they will need to run a compliant and robust procurement process, there is no guidance on procurement routes or evaluation and selection criteria for manufacturers and professional team members.
Contracts
Similarly, there is a missed opportunity in the PAS to refer to forms of contract which would be suitable to engage design team members and manufacturers early and to develop design and manufacturing specification and process collaboratively. The Construction Playbook refers to using standard forms to reduce negotiation and therefore a form such as PPC 2000 which provides for a pre- construction/ manufacturing period, early engagement, multi-party alliancing relationships and use of project bank accounts would seem an obvious choice and would support the recommendations of the Government's Collaborative Procurement Guidance for Design and Construction to Support Building Safety.
