The table below shows current ventilation requirements.

Room	Rapid Ventilation (i.e. opening window area)	Background Ventilation (i.e. trickle vents)
Habitable Room	1/20th of the floor area of the room	8000mm2
Kitchen & Utility	Opening window (no minimum size)	4000mm2
Bathroom/Shower Room	Opening window (no minimum size)	4000mm2
Sanitary Accommodation	1/20th of the floor area of the room	4000mm2

Building Regulation Part F lays down requirements for the ventilation of domestic dwellings for both rapid and background ventilation to suit each room.

Building Regulation Ventilation Requirements
Room	Extract/Rapid Ventilation	Background Ventilation
Kitchens	Mechanical ventilation rated as capable of extracting at a rate of not less than 60 l/sec (or incorporated within a cooker hood and capable of extracting at a rate of 30 l/sec) or PSV. Rapid ventilation by opening window.	Controllable and secure ventilation opening having a total area not less than 4000mm� or by mechanical ventilation being in addition capable of operating continuously at nominally one air change per hour.
Common Spaces in Buildings Containing Two or More Dwellings	No requirement	A ventilation opening with a total area of at least 1/20th of the floor area of the common space.
Bathrooms	Mechanical extract ventilation capable of extracting at a rate not less than 15 l/sec which may be operated intermittently or PSV. Rapid ventilation by opening window.	Controllable and secure ventilation opening having a total area not less than 4000mm�.
Toilets	Rapid ventilation by one or more openings with a total area of at least 1/20th of the floor area of the room, with at least some part of the opening at least 1.75m above the floor level; or mechanical extract ventilation capable of extracting air at a rate not less than 6 l/sec, which may be operated intermittently with 15 minutes overrun.	Controllable and secure ventilation opening having a total area not less than 4000mm�
Internal Toilets	Mechanical extract ventilation capable of extracting air at a rate not less than 6 l/sec, which may be operated intermittently with 15 minutes overrun.	Controllable and secure ventilation opening having a total area not less than 4000mm�
Utility Rooms	Mechanical extract ventilation capable of extracting at a rate of not less than 30 l/sec or PSV. Rapid ventilation by opening window.	Contollable and secure ventilation opening having a total area not less than 4000mm�
Habitable Rooms	Rapid ventilation by one or more openings with a total area of at least 1/20th of the floor area of the room, with at least some part of the opening at least 1.75m above the floor level.	Controllable and secure ventilation opening having a total area not less than 8000mm�

Under Building Regulation clause 1.9 an accepted alternative to the above is the provision of mechanical ventilation designed to be capable of continuous operation throughout the dwelling. This allows the use of whole house ventilation systems to provide an energy efficient solution to the ventilation problem.

Whilst identical in most respects there are a number of differences from the English and Welsh regulations.

Kitchens - a cooker hood of 30 l/sec is accepted as an alternative to the extractor fan.

Habitable Rooms require rapid ventilation openings having an area of 1/30th of the floor area of the room.

Bathrooms with or without Toilet require mechanical ventilation capable of an intermittent extraction rate of not less than 15 l/sec and there is no requirement for a timed overrun.

Toilets require either a ventilator with air opening of 1/30th of the floor area or mechanical extraction capable of 3 air changes per hour.

COMBUSTION AIR
In addition to the Building Regulations the Gas regulations require ventilation of all rooms housing open flued gas fires or boilers of rated input over 7 kW or decorative fuel effect fires covered by BS5871 Part 3.

All vents should be permanent without fly screen.
Extraction fans should not be located in rooms containing open flued appliances.

Competent Persons Schemes for residential property

There are more and more areas of work where Building Regs approval is delegated to registered �competent persons� rather than being done by Building Control Officers.

TYPE OF WORK

Installation of:

Competent scheme type

Heat-producing gas appliances

A person (or employee) approved under Regulation 3 of the Gas Safety (installation & use) Regs 1998

A heating or hot water system connected to a heat producing gas appliance (or associated controls)

A Gas Safe registered heating engineer (but check that they�re registered for that type of work, e.g. installing CH systems).

- An oil-fired combustion appliance with a rated heat output up to 100kW

- Oil storage tanks, and pipes connecting them to appliances

- Heating & hot water systems connected to an oil-fired appliance

A person registered with:

- OFTEC (Oil Firing Technical Association), or

- NAPIT Certification, or

- BESCA (Building Engineering Services Ltd)

- for that type of work

- A solid fuel burning appliance with heat output of up to 50kW (in a building up to 3 storeys including basement)

- Heating & hot water systems connected to a solid fuel burning appliance

A person registered with:

- HETAS or

- NAPIT Certification, or

- BESCA (Building Engineering Services Ltd)

- for that type of work

Mechanical ventilation or air con in an existing dwelling

A person registered with CORGI or NAPIT Certification in respect of that type of work

- Lighting systems

- Electric heating systems, or associated controls

A person registered by the ECA � Electrical Contractors Association - for that type of work

Fixed low voltage electrical installations

A person registered by:

- BRE Certification Ltd

- BSI (British Standards Institute)

- ELECSA Ltd

- NICEIC Group, or

- NAPIT Certification

for that type of work

Replacement windows and doors (where more than 50% glazed) to an existing building

A person registered under

- FENSA � Fenestration Self-Assessment Scheme, or

- CERTASS Ltd, or

- BSI (British Standards Institute)

for that type of work

Sanitary fittings

A person registered with CORGI or NAPIT Certification in respect of that type of work