OSM – Volumetric

Volumetric construction (also known as modular construction) involves the production of three-dimensional units in controlled factory conditions before transportation to site.  Modules can be bought to site in a variety of forms ranging from a basic structure to one with all internal and external finishes and services installed, all ready for assembly.  A family sized dwelling might typically be manufactured in four modules plus roof module(s).

 

OSM – Panellised

Flat panel units are produced in a factory and assembled on-site to produce a three dimensional structure.  The most common approach is to use open panels, or frames, which consist of a skeletal structure only with services, insulation, external cladding and internal finishing occurring on-site.  More complex panels; typically referred to as closed panels, involve more factory-based fabrication and may include lining materials and insulation.  These may also involve include services, windows, doors, internal wall finishes and external claddings.

 

OSM – Hybrid

OSM – Hybrid is a method, also referred to as semi-volumetric, which combines both panellised and volumetric approaches.  Typically, volumetric units (sometimes referred to as ‘Pods’) are used for the highly serviced and more repeatable areas such as kitchens and bathrooms, with the remainder of the dwelling or building constructed using panels.  The hybrid approach is sometimes used to provide added flexibility on complex sites and those requiring additional communal areas.  As with both volumetric and panellised approaches the degree of factory-based fabrication is variable.

 

OSM – Sub-Assemblies and Components

This category is intended to cover approaches that fall short of being classified as systematic OSM but which utilise several factory fabricated innovative sub-assemblies or components in an otherwise traditionally built structural fabric.  Typically, schemes incorporating the use of floor or roof cassettes, precast concrete foundation assemblies, pre-formed wiring looms, mechanical engineering composites, etc. would fall into this category.  Traditional constructed schemes utilising manufactured units – such as windows, door-sets, roof trusses, etc., which might otherwise be part of the fabrication process in the other OSM categories – should not be included as sub-assemblies or components in this category.

 

Non-OSM Modern Methods of Construction

This category is intended to encompass schemes utilising innovative housing building techniques and structural systems that fall outside the OSM categories.  The presence of innovation is an essential feature that might manifest itself through an innovative non-OSM building system, through a building technique familiar in other sectors but new to house building, or through traditional components being combined in innovative ways.  Typically, ‘TunnelForm’ or H+H Celcon ‘Thin joint blocks’ would fall within this category.