Splitting mains feed to holiday let

[GoGetter]

I am building a new small 2 bedroom dwelling (Building A) adjacent (within 15m) of an existing outbuilding (Building B). Building B is currently a workshop and will be converted to be the 'main' (3 bed) dwelling in the future. Building A will then likely become a holiday let, but for now I intend to live there while I convert Building B. As its a rural location and will be fairly low occupancy I have decided to install an electric boiler system like the Heatrae Sadia Electromax in Building A with a wet underfloor heating system, and a log burner for the winter months. The heating pipes are now cast in the floor. This type of boiler runs on the Economy 10 tariff. Building B will likely get a Biomass boiler in the future that could potentially feed the underfloor heating system in Building A and I have installed a microflex duo insulated heating pipe underground in readiness for this.

My question is related to the electric supply, meter position and consumer units. I will be getting an electrician to do the work I just want to dig the trenches and run the cabling right now and ensure that what I am planning is possible and fully understand what would be required.

I am getting SSE to install a new 100A single phase mains electric supply into Building B as this will be the main dwelling. I have already installed an underground armoured cable (SWA 3 core 25mm) from Building B to feed Building A this would be about 15m long. Both buildings will have their own consumer units, the question is how should the feed to Building A be isolated/connected to Building B. I presume the Economy 10 meter for the boiler in Building A would be located close to the mains supply coming into Building B, then perhaps the meter tails connected to an 100A isolator then to the Building B consumer unit, but then how would the feed to Building A be connected, would the feed be split somehow, i.e would it connect to the Building B consumer unit or would it split after the meter then run in the cable I have installed to the consumer unit in Building A?

For Information - Building A (and according to the manufacturer) the Electromax boiler requires a 45A supply to the boiler, a 16A supply for the control panel and boost immersion heater and a 16A off-peak supply for the immersion heater. The consumer unit must be fitted with a double pole 30mA RCD. The electric boiler circuit must include a 45A MCB in the circuit. The immersion heaters must include a 16A MCB in each circuit.

 

[bernardgreen]

Make provision for separate metering to be installed when the holiday lettings begin. Including "free" electricity in the rental price can reduce profit significantly. Lower rental and pay per unit for power used can make the place more attractive to potential renters.

 

[Lectrician]

I find it the opposite - If I am renting a holiday cottage, pay per unit p1sses me off! Especially if it's a coin meter!

 

[bernardgreen]

I find it the opposite - If I am renting a holiday cottage, pay per unit p1sses me off! Especially if it's a coin meter!

I agree with the horrors of coin meters.

If there is a deposit then deduct the cost of any excessive use of power from the deposit. Allow for a fair amount in the rent per week but ( in the small print ) make it clear that any more than that amount will be charged for.

 

[stem]

I would be very wary of using electricity with a wet heating system.

Low rate electricity (Economy 7 or 10) has only limited availability, mainly at night. Whilst this is helpful for heating the stored domestic hot water, it's not so good for wet central heating which is normally required in the daytime when it will use full rate electricity which is very expensive. (approx 3 times the cost of mains gas, and double the cost of low rate electricity per KW)

If mains gas isn't available, electric storage radiators may be a better alternative as they slowly release heat that has been stored up only using the low rate.

 

[dhutch]

My parents have electric underfloor (ie, large resitance cables, inplaced o pipes) and this works well, on economy 7. There is something like 12-14kW for a four bedroom house, twin inch cavity wall and good loft insluation, which is enough for all but the coldest fortnight of each year, when it needs some help in the form of a solid fuel fire.

Other than doing sums on making sure you you can get enough energy into it I see no issues with suing a wet-electric system. Although obviously if you want fast heat up for a holiday let you need more. My parents house takes about two days to come upto temp.


Daniel