Regulation 421.1.201

Guidance would suggest they are - it's not entirely clear from the wording of the regulation itself ("premises" is usually taken to mean the entire curtilage, including surrounding land and outbuildings) but the qualification "(household)" seems to been intended to restrict the scope to those parts of the premises normally resided in by the household (i.e. habitable areas).

   - Andy,

AJJewsbury said:

"premises" is usually taken to mean the entire curtilage, including surrounding land and outbuildings

Didn't we discuss this a few days ago. As I asked then, if my garage is not included in my premises, in whose does it lie?

AJJewsbury said:

Guidance would suggest they are

The key concern is the sleeping risk in premises that are not normally subject to the statutory FRA. Assessing the proposal to use a plastic consumer unit in a detached garage could be extracted from Section 11 in Approved Document B vol 1. Meeting the boundary requirements should give confidence. 

lyledunn said:

The key concern is the sleeping risk in premises that are not normally subject to the statutory FRA. Assessing the proposal to use a plastic consumer unit in a detached garage could be extracted from Section 11 in Approved Document B vol 1. Meeting the boundary requirements should give confidence. 

This in effect is the indirect conclusion in Section 7.3 of the IET's Guide to Consumer Units, the second paragraph of which states:

Looking into the connection arrangements within the 'household' premises, if there is a supply to an attached or integral garage, then any consumer unit within that garage would also be subject to the new regulation. If the garage is detached, there is still a strong argument for applying the new regulation, given the known risks. With that in mind, any supply to an outbuilding or a detached garage would need to be carefully considered in terms of, for example, its proximity to the main dwelling house and the use of the outbuilding. Any decision not to use a non-combustible consumer unit would need to be justified.

What decision could possibly be made that are justifiable, is cost a justification? 

AMK said:

What decision could possibly be made that are justifiable, is cost a justification? 

Not sure I follow that ... proximity of the detached garage to the house is a consideration for protecting people in  the house from fire ... but people could still get hurt if their garage sets on fire, particularly if there are stored fuels etc. in there.

If a plastic consumer unit is selected for a detached garage (separate from the main property), would it be necessary to document the reasoning on the Electrical Installation Certificate ? For instance, considerations such as minimal fire risk and budget constraints may justify this choice.

If a plastic consumer unit is selected for a detached garage (separate from the main property), would it be necessary to document the reasoning on the Electrical Installation Certificate ? For instance, considerations such as minimal fire risk and budget constraints may justify this choice.

AMK said:

If a plastic consumer unit is selected for a detached garage (separate from the main property), would it be necessary to document the reasoning on the Electrical Installation Certificate ? For instance, considerations such as minimal fire risk and budget constraints may justify this choice.

Perhaps ... but would anything need to be documented if it's not a 'departure' ?

This guidance indicates perhaps not a departure for a detached outbuilding: https://www.electricalsafetyfirst.org.uk/professional-resources/technical-e-news/consumer-unit-mythbuster/

BUT

If you take the words as written in Regulation 421.1.6 BS 7671:2018+A2:2022+A3:2024 at face value, then:

1. Domestic (household) premises is, to the best of my knowledge, a clearly defined term that includes the house, outbuildings and the entire curtilage of the 'premises'.
   
   
2. 'within' does not have to mean 'indoors', it can mean (and would make most sense to mean, given 1. above), 'within the curtilage of the premises'.

Now, I'm not going to provide a specific opinion ... I can clearly see there are differing views on this, and the answer may well change with changing circumstances.

I would point readers of this thread to the advice given in Clause 4.2.3 of BS 0:2021, that interpretation of the standard is the responsibility of the user of the standard, and only a court of law can give a definitive interpretation.

gkenyon said:

'within' does not have to mean 'indoors', it can mean (and would make most sense to mean, given 1. above), 'within the curtilage of the premises'.

Exactly! One might say, for example, that the Bank of England lies within the City of London.