New build electric connection

[ecogeorge]

Hope i'm posting in the correct board. Need advice for a friend for new house electrical connection. Cost is paramount and obviously needs to meet current regs.
We'll call him John (cos that's his name) owns a small farm with a small Dairy milking goats. He lives in a EnSite mobile home and after getting planning has almost finished his new permanent house.
He needs to connect electricity to the house from the holding supply which is approx 40m away.
The supply is single phase fused at 80A.
I have attached a photo which shows the supply in this order - incoming fuse 80A - smart meter-DP ISOLATOR-Change over switch (he has a tractor generator for power cuts) -then to DB1.
DB1 has several mcbs and spare ways.
Main MCBs are c40 Dairy unit / c32 Mobile Home / c20 Shed/c20 Shed.
The Dairy unit occasionally trips the C40 - overloaded -based on cable size but can live with by using timeclocks on water heaters/ ice building etc.
The Mobile home will be removed once the new house is in use. Sheds are only lights /sockets -no heavy loads.
Electrician who has completed first fix on house has said he needs to contact his DNO to arrange a separate supply from the meter for the house .
He is concerned at the cost of this and has asked for advice.
My thoughts were several---
1) connect supply though spare MCB way say using a c50 (or bigger?) size cable to house accordingly but its a modest house with no huge loads.
or
2)Where the supply to DB1 leaves the change over switch fit a Henley block and take the full 80A supply to the house. Then fuse/wire as normal.
Anyone got any thoughts / ideas as to correct/cheapest solution. Really don't want to involve Western Power (DNO). Also do not want 2 meters.
Thanks in advance
George

[Stinsy]

Either option is fine. He definitely doesn’t need a new supply!

Assuming a modest house with no: electric shower, EV charging point, or resistive heating, or anything else similar, and particularly if he’s cooking with gas, then 10mm² armoured cable hanging off a 50A MCB will be fine (could even be fine with a 40 or 45). It is amazing how efficient modern appliances are!

The alternative would be to split the tails and run 25mm² armoured to the house. This is the option to chose if he wants electric oven/hob etc.

Your friend really should invest in some solar/batteries, seems like his goat-milking enterprise consumes a lot of energy. He’d save a fortune!

[ecogeorge]

No mains gas , Mobile home is bottles........
He's like me (tight ) but hadn't thought of cooker/oven/electric shower but unlikely to be in use as same time as working on goat unit.
He's keen for solar (has roof and land space) but money so tight as just bought additional land .......
George

[AGT]

Wouldn’t feed a house board from a MCB due to selectivity

Different if it were a board full of MCCB’s, anyway,

I would split the tails and install a KMF unit and fuse it down appropriately as per your option 2
16kW for 40 m on 10mm2 3 core swa.

[Stinsy]

Selectivity regards RCDs not MCBs.

[Gareth J]

Option 2. Henley blocks and appropriate breaker/isolator yo protect the supply cable. Plenty of farmhouses are on the same supply. If regs have changed that disallow this on new installs, ask for clarification.

Oversizing the cable for future upgrades; EV charge point, heat pump, Solar is cheap now compared to digging up concrete to add another cable later.

It might seem a bit odd but also consider adding a second cable or conduit in the trench. If he's considering PV in the future, you really want any diverter device/s to monitor outgoing elec at the meter point, so the fam has a chance of using the PV too. But there's probably going to be a hot water tank to fill in the house. He might get a wireless CT to do that distance if he's careful about locating each end. Or could send the power directly down its own SWA or stretch a wired CT all the way via a Comms cable. Hope that makes sense.

[Stinsy]

Option 2. Henley blocks and appropriate breaker/isolator yo protect the supply cable. Plenty of farmhouses are on the same supply. If regs have changed that disallow this on new installs, ask for clarification.

Oversizing the cable for future upgrades; EV charge point, heat pump, Solar is cheap now compared to digging up concrete to add another cable later.

It might seem a bit odd but also consider adding a second cable or conduit in the trench. If he's considering PV in the future, you really want any diverter device/s to monitor outgoing elec at the meter point, so the fam has a chance of using the PV too. But there's probably going to be a hot water tank to fill in the house. He might get a wireless CT to do that distance if he's careful about locating each end. Or could send the power directly down its own SWA or stretch a wired CT all the way via a Comms cable. Hope that makes sense.

If he wants a charging point in future then hanging it off of the house CU is a bad idea. Best to come off the CU by the meter.

[Swwils]

Surely he wants two meters so the dark can be on commercial rates

[AGT]

Single smart meter will give you dual tariff though

[Gareth J]

Option 2. Henley blocks and appropriate breaker/isolator yo protect the supply cable. Plenty of farmhouses are on the same supply. If regs have changed that disallow this on new installs, ask for clarification.

Oversizing the cable for future upgrades; EV charge point, heat pump, Solar is cheap now compared to digging up concrete to add another cable later.

It might seem a bit odd but also consider adding a second cable or conduit in the trench. If he's considering PV in the future, you really want any diverter device/s to monitor outgoing elec at the meter point, so the fam has a chance of using the PV too. But there's probably going to be a hot water tank to fill in the house. He might get a wireless CT to do that distance if he's careful about locating each end. Or could send the power directly down its own SWA or stretch a wired CT all the way via a Comms cable. Hope that makes sense.

If he wants a charging point in future then hanging it off of the house CU is a bad idea. Best to come off the CU by the meter.

In an ideal world, sure. Many farms will have a meter somewhere they don't want to park though. Potentially academic anyway if the person isn't planning an EV.

Surely he wants two meters so the dark can be on commercial rates

House and farmhouse on a single meter is not a barrier to business/commercial tariff.