3 storey house HMO

[adsmith]

hi guys

Have a 3 storey house (loft converted) that is getting converted into a HMO with 5 x bedrooms, 1 x communal living room and 1 x communal kitchen. Each bedroom has its own bathroom. The main incoming cable is on a 100amp fuse. The landlord is not bothered about what tenants elec usages so home is to only have one meter.

With the loft being converted does it require it own fuse board? And if so do I run meter tails all the way to the loft from a Henley block at the incomer?

I was thinking on one board having just the ground and first floor circuits such as

3 x 32amp ring mains (ground, first floor and kitchen sockets)

2 x 6 amp lighting circuits (ground, first floor)

1 x 6amp fire alarm system

1 x 32amp elec hob
1 x 16amp oven

Then having a seperate consumer unit in the loft bedroom for just sockets and lighting?

Correct me if I am wrong please. Thanks

Andy

 

[westward10]

Are you an electrician.

 

[BruceBanner]

Yeah! Kind of second that.

 

[adsmith]

Are you an electrician.

I am an industrial electrician yes who will be giving a friend a hand who is a domestic electrician

 

[BruceBanner]

I am an industrial electrician yes.

OK. Credit to you. Who's signing this of?

 

[Dartlec]

I am an industrial electrician yes.

The new consumer unit will all be notifiable under Part P, so if you aren't a member of a scheme you'll need to consider that.

Most councils are very hot on HMO and they attract some additional legal requirements in terms of fire safety etc, so if the landlord hasn't already had a discussion with the council it would be best to get them involved.

I see no reason for an extra board in the loft, but if there was you would have to additionally protect the feed to it, and not rely on the main DNO fuse as protection (they don't allow it over 2-3m).

RCBO on all circuits (fire protection a possible exception), and SPD protection is likely the way to go with any installation.

 

[bigspark17]

If your taking this job on you shouldnt be asking these kind of questions mate. I expected to see question regarding loading or fire detection when clicking the hmo link not something like this.

 

[adsmith]

OK. Credit to you. Who's signing this of?

My friend who is carrying out the work. To be honest he will be calling the shots. I've just put this post up to confirm or correct my own knowledge for learning and just wanted feedback to see what I thought would be ok or not

 

[BruceBanner]

The new consumer unit will all be notifiable under Part P, so if you aren't a member of a scheme you'll need to consider that.

Most councils are very hot on HMO and they attract some additional legal requirements in terms of fire safety etc, so if the landlord hasn't already had a discussion with the council it would be best to get them involved.

I see no reason for an extra board in the loft, but if there was you would have to additionally protect the feed to it, and not rely on the main DNO fuse as protection (they don't allow it over 2-3m).

RCBO on all circuits (fire protection a possible exception), and SPD protection is likely the way to go with any installation.

He should know this, I am not trying to berate anyone, but the liability issues on this are considerable.

 

[westward10]

There is no reason to have a separate board in the loft unless volt drop requirements are difficult to meet although I find this unlikely.

 

[BruceBanner]

Then I assume your friend who has all the tickets/etc , a design/"plan for this install/, all aspects & consulted with the local authority, their determination of the rules varies quite a bit.

 

[Dartlec]

Then I assume your friend who has all the tickets/etc , a design/"plan for this install/, all aspects & consulted with the local authority, their determination of the rules varies quite a bit.

Even outside of electrical there are plenty of things some councils will want - I did some work on a 2 storey one for a landlord in a London council and iirc had it been a 3 storey a whole new level of requirements would have kicked in re fire escape, etc.

Some of their requirements may well exceed BS7671 (and other standards) and their word will be law - so I do hope the landlord has got them involved already.

 

[pc1966]

There is no reason to have a separate board in the loft unless volt drop requirements are difficult to meet although I find this unlikely.

Yes, I was also wondering "Why?" on that point.

Most obvious is if it is totally separate access/ownership, but that seems unlikely in this situation. Sure it is a bit more effort to go 3 floors to reset but then that is (or should be!) an uncommon occurrence. The total loads & complexity per-floor can't be that great to justify per-floor DBs that large buildings might have.
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I guess worst-case is the RFC reaching the length-limit for 2.5mm, but simply running the legs to the DB in 4mm is probably enough to overcome that.

 

[Dustydazzler]

First wuestion is the house being fully rewired or are you just rejiggimg & extending the existing wiring ?

if it’s a full rewire I would take one lighting and one power circuit to each room from a central DB (no need for additional boards) and label the new DB room 1 , room 2 , room 3 etc etc
if you are rehashing the existing then just do the best you can with what’s already there.
dont forget mains interlocking smoke & heat alarms and imo emergency lighting in all communities areas

 

[UNG]

dont forget mains interlocking smoke & heat alarms

Three storey HMO's usually require a BS5839 Pt 1 system not mains alarms