calculating power requirements for a new build house

[Galfredus]

But if you say why you have considered 3 phase then maybe we can give a more informed answer.

I only considered three phase because of the possibility of electric heating. But if that is unlikely to require it then there's probably no point.

Just out of interest, is it a lot more expensie to get a connection than single phase?

Thanks

G

 

[ericmark]

I have never priced it against single phase. Only time I was involved in getting new supply we were talking about dedicated 11kv transformers.

I have looked at the new central tank water storage systems seems two basic types open vented and closed vented the latter seems to have a maintenance problem.

But I live in a soft water area it is completely different in hard water areas.

I do know what you mean by in case. The first house I bought had loads of power cuts and we were very careful when we moved to have a method of heating when the power went off. We had a very big gas fire installed. but in new house hardly ever have power cuts so fire hardly ever used.

Solid fuel is the same. I was brought up in a house using solid fuel and know the problem with a wind change and banking up a fire. But also lived in houses on the Falklands using solid fuel and there are so many factors which mean in one house they can bank fire for 3 days and another has a job to last 12 hours.

As a result I may allow for upgrade in future but would not start with a 3 phase supply.

Little things like using a radial for each room instead of a big ring main will allow you at a later date to feed a phase to each room or even restrict to power to one room where lodgers sneak in an electric fire.

We refer to it as making house future proof. Although it never works, saw one house with LAN cables taken to each room from where the telephone cable entered house. Seems great idea. Then new owners used wireless!

 

[flameport]

I'm not talking about separate storage heaters, but a single unit heating a LPHW system via a heat exchanger.

If you have one of those, you will probably want Economy 10 rather than E7.

Just out of interest, is it a lot more expensie to get a connection than single phase?

Very likely. Although the difference between a 2 core and 4 core cable is small, the DNO can and will charge more for anything which is non-standard.

There will also be significant additional costs when the property is wired, as you will need a 3 phase board, which will most likely be an industrial style one. The wiring layout will also be completely different, as the total load should be split across the 3 phases.

In some (mainly rural) areas, it may not be possible to even have 3 phase.

A 5 bedroom house does not need 3 phase.

 

[Pensdown]

If they are asking for a kva figure, 15 or 17 is probably what you want.

A 5 bedroom house does not need 3 phase

Thats gets my vote

 

[Galfredus]

Thanks guys! This has been really quick and really helpful.

G

 

[Stoday]

I got a quote from EDF for a single and a three phase supply to my self-build house three years ago. It was less than £100 extra for three phase, just the extra cost of the service cable and joint.