G4/AS1: Ventilation

G4 VENTILATION ACCEPTABLE SOLUTION G4/AS1 Contents Contents PART 1. GENERAL ....................................................................................................................... 6 1.1 Introduction ......................................................................................................................... 6 1.2 Using this acceptable solution .............................................................................................. 6 PART 2. SPACES WITHIN BUILDINGS ........................................................................................... 8 2.1 Ventilation of spaces within buildings .................................................................................... 8 2.2 Natural ventilation ................................................................................................................ 8 2.3 Mechanical ventilation ........................................................................................................ 11 2.4 Combined natural ventilation and mechanical ventilation ..................................................... 12 PART 3. GAS-FUEL APPLIANCES ................................................................................................. 13 3.1 Natural ventilation .............................................................................................................. 13 3.2 Mechanical ventilation ........................................................................................................ 13 3.3 Flue locations on dwellings ................................................................................................. 14 3.4 Another solution for gas-fuel appliances .............................................................................. 14 APPENDIX A. REFERENCES ..................................................................................................... 15 APPENDIX B. DEFINITIONS ..................................................................................................... 16 APPENDIX C. EXAMPLES OF VENTILATION OPTIONS ................................................................ 18 C.1 Typical apartments ............................................................................................................. 18 MINISTRY OF BUSINESS, INNOVATION AND EMPLOYMENT 28 JULY 2025 Page 5