The benefits of light steel framing and modular construction in housing in

terms of thermal performance are:

• U-values of less than 0.15 W/m2K can be achieved cost effectively by lightweight construction without leading to excessively thick walls.
• High levels of airtightness (less than 3 m3/m2/h) can be achieved by use of sheathing boards and membranes that are provided in light steel framing and modular systems.
• Extensive thermal analysis of construction details has led to predictive y-values of less than 0.08 W/m2K in whole building energy models.
• High levels of insulation and low thermal mass do not lead to excessive over-heating (as heat is not stored over successive hot days).
• Thermal isolating details have been developed for balcony attachments to reduce thermal bridging.
• Lightweight systems do not suffer from over-heating in the summer and they are more responsive than heavyweight systems.
• The off-site nature of modular construction means that higher levels of air-tightness and greater reliability of the building fabric are achieved.
• Renewable energy technologies may be built-in or attached to improve the energy balance of the building and zero energy design can be achieved.