1. the type of installation
2. its use and operation
3. the frequency and quality of maintenance
4. the external influences to which it is subjected

The table below provides guidance on the frequency of formal inspections of electrical installations as well as routine checks.

Type of Installation	Routine Check	Maximum Period between inspections and testing as necessary	Reference (see notes below)
General installation
Domestic	N/A	change of occupancy/10 years	N/A
Commercial	1 year	change of occupancy/5 years	1,2
Educational establishments	4 months	5 years	1,2
Hospitals	1 year	5 years	1,2
Industrial	1 year	3 years	1,2
Residential accommodation	at change of occupancy/ 1 year	5 years	1
Offices	1 year	5 years	1,2
Shops	1 year	5 years	1,2
Laboratories	1 year	5 years	1,2
Buildings open to the public
Cinemas	4 months	1 year	2,6,7
Church installations	1 year	5 years (quinquenially)	2
Leisure complexes	4 months	1 year	1,2,6
Places of public entertainment	1 year	5 years	1,2,6
Restaurants and hotels	4 months	1 year	1,2,6
Theatres	4 months	1 year	2,6,7
Public houses	1 year	5 years	1,2,6
Village halls/Community centres	1 year	5 years	1,2
External installations
Agricultural and horticultural	1 year	3 years	1,2
Caravans	1 year	3 years	N/A
Caravan parks	6 months	1 year	1,2,6
Highway power supplies	as convenient	6 years	N/A
Marinas	4 months	1 year	1,2
Fish farms	4 months	1 year	1,2
Emergency lighting	daily/monthly	3 years	2,3,4
Fire alarms	daily/weekly/monthly	1 year	2,4,5
Laundrettes	1 year	1 year	1,2,6
Petrol filling stations	1 year	1 year	1,2,6
Construction site installations	3 months	3 months	1,2

Reference Key

1. Particular attention must be taken to comply with S1 1988 No 1057. The Electricity Supply Regulations 1988.
2. S1 1988 N0 635 The Electricity at Work Regulations.