The following check-list defines the range of questions that the architect may raise in discussion with the modular supplier. The list is not definitive but covers the broad issues. The architect should also address issues related to design responsibility, relationship between the modular supplier and main contractor, and architectural opportunities within the overall manufacturing and constructional technology.
Detailed discussions should be held with the chosen modular supplier. Contractual relationships and duties of the architect may influence the timing and responsibilities for resolving these issues.
C Is the overall building shape appropriate to the economic use of modular construction or alternatively to mixed use of modular construction and panel systems?
C How high can the modules be stacked, and at what point are other strengthening members or support frameworks required?
C When modules are used in combination with steel or concrete frameworks in new or existing construction, are any special measures required and what are the methods of installation?
C Can modular units be placed in a staggered arrangement with off-sets on the facade to create balconies and more interesting details?
C At what scale of repetition is the modular approach economical?
C Can the units be made with raked sides and non-rectangular on plan (e.g. curved facade)?
C How can modules be combined to create large open spaces or glazed facades?
C What are typical module sizes? Are there any transport or site restrictions on the size of modules for delivery?
C Are typical interface details with cladding, roofing, foundations, balconies, lifts available?
C Is the pre-manufacture of a prototype unit required in order to assess feasibility and ease of manufacture and transport before production begins.
Procurement and costs
C What are the different procurement routes that may be employed? How is a competitive element between modular manufacturers maintained?
C At what point does the final design become ‘fixed’ before committing to production?
C What are the performance requirements for modular construction?
C Who takes responsibility for the adequacy and performance of the modular units and the final design?
C What are typical module costs in £/m2, depending on the level of fit-out required?
Can these costs be provided at the scheme design stage?
C Does the manufacturer tender at scheme design stage or at final design, and how is the manufacturer’s design input recognised?
C What are potential time savings in the modular route, and other benefits in terms of theconstruction programme?
C What guarantees and independent approvals are available (e.g. Agrement or Lantac)? What is the design life of the modules?
C What guidance on contractual responsibility is available? Does the architect /nominate, the module supplier?
C What guarantees or warranties are available?
C What factors will determine the size and repetition of the modules, e.g.
-local roads for transport
– site constraints and cranage
– room sizes to be created.
C Are the modules edge supported or corner supported and what are the implications for foundations, cladding, services etc? Are there special requirements for tall buildings?
C Is bracing required and, if so, where can bracing elements be located in open-sided modules? What is the length of the side of a module that can be left open?
C What interface details for the chosen cladding systems are appropriate?
C How are balconies or other features attached to the modular units, or can they be manufactured as projections to the modules.
C How can the building facade be modified to create the required architectural style?
C What are the typical wall, floor and ceiling thicknesses?
C What are the sensible acoustic insulation and thermal insulation characteristics that can be achieved?
C Where are major service routes located both horizontally and vertically? Can rainwater pipes be incorporated internally?
C How are service connections between units made, and how can they be accessed for maintenance?
C How is the spread of fire prevented between modules, and what fire resistance period can be achieved for the modules?
C What information is required for building control, and who provides structural details of the module design and the supporting design calculations?
C Who takes responsibility for dimensional coordination?
C How and when are lifts and stairs installed?
C What British Standards are appropriate to modular construction?
C What degree of differential foundation settlement can be resisted without distress. Are movement joints necessary? Is a separate foundation required for the masonry facade?
C Can cladding and windows be attached in the factory, and what features may be used to conceal the joint between the modules? How is the cladding protected during transportation?
C How is insulation attached? In what circumstances can it be fitted between the wall studs, or must it be placed externally?
C What are the attachments between the modules and to the foundation?
C Can brickwork coursing be arranged to suit window openings, taking account of module heights and construction tolerances?
C What dimensional tolerances are appropriate for manufacture and for site installation?
C What materials are appropriate to protect the modular units during transportation?
Can they be left in place after construction?
C What details are used for the floor-floor junctions, including floor coverings?
C At what stage are the working details of the modules and their attachments provided?
C How does the designer deal with CDM issues (and safety plans)?
C What notice is required for police escort, if necessary?
C How can deliveries be timed to suit road restrictions?
C Who provides the cranage – the main contractor or the modular supplier? Is special cranage required for tall buildings?
C What is the typical weight of a module?
C What area is required for off-loading the units? Can the units be placed directly in their final location?
C Who makes the service connections and ensures satisfactory installation?
C If cladding is installed in the factory, who co-ordinates the later site infills?
C Can floors and tiles be bonded satisfactorily? What remedial work may be required on site?
C Can pre-compliance trials be done off site and who is responsible for them?
C What maintenance schedule is given or is necessary?
C How can any trapped water during construction or due to a burst pipe be dealt with?
C How can the modular units be adapted at a later date?