11.1.3 System Manual
Designs and specifications, in the form of a System Manual, shall be produced in a clear and understandable format, include all relevant information, and be distributed to all appropriate personnel.
A System Manual and supporting design information should be issued to NHBC at least eight weeks in advance of the works starting on site, in accordance with NHBC rules. Further performance issues may be considered at the discretion of NHBC, and further information requested. If in doubt, consult NHBC Standards, Innovation and Research (technicalsupport@nhbc.co.uk).
The System Manual should contain the information described in Table 1 as relevant for the system.
Table 1: Items included in the System Manual
| Topic | Description |
|---|---|
| System Details | • manufacturer name
• system name • document revision number • issue date |
| Scope and limits of application | • description of the system and scope of offsite manufactured elements
• intended use and limits of application or exclusions (geographic/environmental, storey height, dimensions, building type and shape, etc) • confirmation of parties, who have responsibility for the design and coordination of the system, certification of the system quality assurance and who has overall responsibility for the delivery of the home |
| Standard detail drawings | • schedule of standard detail drawings |
| Material specifications | • specifications and relevant third-party certificates for all key materials and standard components critical to the performance of the system |
| Durability | • demonstration of adequate durability of components and assemblies in accordance with Technical Requirement R3
• specification of fixings, including corrosion protection • temporary weather protection design and method |
| Strength and stability | • structural design philosophy (including codes of practice referenced, test reports and
identification of design aspects not covered by codes for which additional checks or
assessment are required)
• sample structural calculations for typical design • material strengths and/or grades (traceability) • section properties • loading • ultimate limit state • serviceability limit state • resistance to overturning • racking resistance • holding down • connections within the system • connections with other building elements • structural integrity • positions and sizes of holes through members • unit-to-unit connections (strength as well as accuracy) • unit-to-foundation connections • rigidity in transportation • lifting |
| Behaviour in relation to fire | • reaction to fire
• resistance to fire including fire test reports, and supporting assessments where required, demonstrating compliance with Building Regulations • fire compartmentation design • design and specification of cavity barriers and fire-stopping |
| Resistance to moisture | • vapour permeability and moisture resistance of building fabric and suitable assessment of interstitial and surface condensation risk
• watertightness of the building envelope including integrity and continuity of building membranes and weather resistant detailing at junctions and interfaces • resistance to moisture from the ground |
| Safety in use | • consideration of changes in levels
• resistance to eccentric loads, including impact resistance |
| Resistance to the passage of sound | • sound insulation performance and design |
| Energy efficiency | • thermal resistance of building fabric including assessment of thermal bridging at typical
junction and interface details
• air permeability design |
| Coordination of services | • specification of factory installed services
• method of testing and commissioning • method of access for site connections, inspection, and commissioning • allowance for tolerances of site connections to factory installed services |
| Quality of finish | • quality assurance process for achieving quality of finish in accordance with NHBC Standards |
| Evaluation of conformity | • evidence of Quality Management System (QMS) in accordance with ISO 9001:2015
• Factory Production Control (FPC) plan • non-conformity procedure • traceability and unit identification procedure • inspection and test plan • storage, transport, and installation procedures |
Last updated: 2nd January 2025