House to annexe cabling question

[DavidUK]

Hi all.

Looking to buy a house where the rear of the house is the rear boundary, onto council owned land (a footpath).

I want to build a new garage with living accommodation above around 20m in front of the house. The house consumer unit is right at the back of the house, in the middle of the rear wall.

Is it possible to run the new cabling from this location along the rear wall of the house (there is access all along) and then go underground on my land to the new garage/annexe?

I'd have an electrician install this of course, just need to know before I offer on the house.

Many thanks all!

 

[timhoward]

Is the meter in the same vicinity as the consumer unit, or any nearer the front?
Your proposal doesn't sounds impossible but in my opinion I'd try and avoid having a cable running along a wall that's a public footpath.
Depending on the direction of joists it may be preferable to run it up and to the side of the house and then down and underground.
In general we always find a way, and there will be a way.

I can't help wondering, have other properties done similar, or is there outline planning permission in place already for a garage with living accommodation? I'd have thought that might be a bigger concern than getting power to it. Just speaking my mind - sorry if you have this all sorted!

 

[pc1966]

As above, perfectly possible but maybe not the best way, it is not a reason to worry about in terms of buying the property!

For the cable run steel wired armour cable would be the usual choice as it is tough enough to go underground and (relatively) safe if it is hit by a spade, etc. However, for a cable near public access you really would also want some capping over it to make it less obvious/easy for some scroat to try stealing it or simply yanking it off the wall, etc. The minimum bend radius for such cables is significant so you can't just drill through and bend 90 deg on a penny, it needs a bit of a curve cut, etc, or a transition from SWA to conduit, etc, at the outer wall to bring the conductors in safely with smaller minimum bend.

Putting in duct for the cable is also a good idea, even though it can be buried directly, as it allows future changes if needed. You should also think about running a network cable as well, that can go in the duct as you do get duct-grade and even armoured cables for networking, then a separate Wi-Fi point out there, etc.

Even if the sparky is not going to do any network stuff (some do, some don't) at least you will have a cable available for the future at little extra cost.

 

[DavidUK]

The meter is with the consumer unit, under the double dog leg staircase at the rear of the house.
To the right of this understairs cupboard is a bedroom which has a built out skirting board along the rear wall for pipes I believe. Then carrying along the rear wall, inside, in the direction of the proposed annexe is a cupboard, then the kitchen which has units along the full width of the rear wall, then into the next room into the boiler cupboard, then through to utility with units the full width of the rear wall, then the right hand wall. Go through this and you're on owned land.

So I'm thinking any cabling could be run just inside the rear wall through all these rooms without being seen. Some kind of connectable conduit, so as to keep a continuous run, could be put in (if such a thing exists) to run the annexe cable and any others. What about cable heat build-up inside conduit or enclosed space, is that a concern? I guess the gauge of cable would allow for this.

The annexe planning is going to be tricky... conservation area. But it's for our autistic son to live in so hopefully we can work with the planners, as we did in another conservation area. Pre-planning meeting is the best way in my experience, then neither party have any surprises later.

 

[timhoward]

You may well be right about the best route. Without looking at it, having a cuppa, then weighing up options it's hard to say!
Boiler cupboards can often be useful to run cables between floors - in this case it could be a way to get the cable to the joists in between the floors and then just about anywhere you like as long as boards can be lifted.
I've hidden a cable behind a drain pipe on the front of a house a couple of times

I wouldn't be too concerned about it, sparks enjoy being ingenious and there will definitely be a way.
I hope it all works out for you regarding the planning.