HMO standards

Find guidance for the minimum standards in HMOs. 

Lighting, ventilation and heating

Natural lighting

  • All habitable rooms must have a window or glazed door that opens to the outside.
  • The glazed area must be at least 10% of the room’s floor area.
  • Basement rooms used for living or sleeping must have enough natural light for safe and comfortable use.

Kitchens, bathrooms and toilets

  • These rooms should meet the same natural lighting standard as above.
  • If this is not possible, they must have suitable artificial lighting (see the artificial lighting section below).
  • All bathroom and toilet windows must use obscure glazing for privacy.

Staircases, landings and hallways

  • These areas should have a window with clear glazing to provide natural light.
  • If this is not possible, they must have suitable artificial lighting (see the artificial lighting section below).

Artificial lighting

  • All habitable rooms, kitchens, bathrooms, toilets, staircases, landings and hallways must have adequate artificial lighting.
  • There must be enough light switches on each landing, hallway or passage.
  • Switches should allow all shared areas—like hallways, passages and stairways—to be lit at the same time.

Lighting in shared areas

  • The landlord or their agent must provide, maintain and pay for lighting in all shared areas.
  • Time switches can be used in shared staircases, landings and hallways.
  • These switches must stay on long enough for someone to safely climb the stairs or reach a room.

Ventilation

Habitable rooms

  • All habitable rooms must have a window that opens directly to the outside.
  • The openable part of the window must be at least 1/20 of the room’s floor area.
  • Doors to the outside do not count toward this requirement.
Basement rooms
  • If a basement room is used for living or sleeping, there must be an open space outside the window.
  • This space must:
    • run the full width of the window (or more)
    • be at least 0.6 metres deep from the external wall
    • or at least 0.3 metres deep if the window is a bay window with side lights

Kitchens, bathrooms and toilets

  • These rooms should meet the same window ventilation standard as above.
  • If this is not possible, mechanical ventilation must be installed.
  • Mechanical ventilation must:
    • be controlled by a humidistat or run for at least 15 minutes after the light is turned off
    • be wired to the light switch
    • provide at least 4 air changes per hour
    • extract at a minimum rate of:
      • 60 litres per second for kitchens
      • 15 litres per second for bathrooms

Permanent ventilation

  • Permanent ventilation must be provided and maintained in:
    • all kitchens, dining/kitchens, bathrooms and toilets
    • any room with cooking or washing facilities
    • any room with a gas appliance

Space heating

  • All habitable rooms and bathrooms must have a suitable heating appliance.
  • The appliance must be properly maintained and able to provide:
    • 21°C in living or sleeping rooms
    • 18°C in all other areas
    • when the outside temperature is -1°C

Acceptable heating appliances

Heating must be provided by one of the following:

  • A fixed gas fire with a proper flue
  • A fixed electric heater, connected to the main electrical supply
  • An efficient, effective and economical space heating system.

Additional requirements

  • All bathrooms must have suitable space heating.
  • All heating must be controllable by the occupant.
  • Portable oil or gas heaters must not be used anywhere in the property.