Building Regulations – 2021 Edition

Part F

Volume 1 is dwellings and Volume 2 buildings other than dwellings

Volume 1 principal impacts:

• Potential increase in whole dwelling ventilation rates
• Increase in the minimum free areas for background ventilators

Volume 2 principal impacts:

• Requires CO2 detectors for certain sizes of spaces
• Increased focus on indoor air quality
• Requires the provision of natural or mechanical fresh air ventilation to circulation spaces (corridors, staircases and lift lobbies)
• Increase in ventilation plant costs
• Potential reduction in NIA to house common space ventilation equipment

Part L

Volume 1 is dwellings and Volume 2 buildings other than dwellings

Principal impacts:

• Must comply with enhanced notional buildings
• Improved fabric efficiencies
• Less flexibility in the way buildings are designed
• Potential reduction in commercial buildings NIA
• Improved plant efficiencies (and therefore equipment costs)
• Changes to fuel conversion factors
• Analysis of high efficiency alternative systems
• ‘Nearly net zero energy’ buildings
• Reduced running costs
• Greener buildings
• Increased facade costs (to improve thermal bridging)
• Reduction in acceptable air permeability

Part O

• Enhanced fabric performance
• Potential introduction of shutters/overhangs/external shading devices
• Reduction in glazing size and glazing properties
• Less flexibility with façade/building design
• Increased window costs (to allow a greater number of opening windows)
• Increased emphasis on cross ventilation
• Increase in the use of mechanical ventilation
• Increased costs and timeframe for designs to allow for iterations to overcome overheating to take place
• The simplified methodology cannot be used for apartment buildings
• Increased plant/build costs to overcome risks identified at design stage