As well as budgeting for your garden office building, you also need to put some money aside for the connection of the garden offices electrics to the mains supply in your house.
The majority of garden office suppliers we have contact with ask the customer to organise this aspect separately to the package they offer. The reason is that while garden offices are pre-wired in the supplier’s workshops with all its electrics, the actual connection to the mains and the testing of the circuit needs to be undertaken by a certified electrician. Most garden office suppliers don’t send a qualified electrician to site, so ask you to engage someone locally.
What’s involved in the electrical hook-up?
The process of connecting a garden offices electrics to the mains supply involves running an SWA sub-main cable rated at 45Amps buried in a trench from the site of the office to the house. This connects the consumer unit in the office to the unit in your house.
The digging of this trench involves a lot of work, and you then have to backfill with a layer of stone and warning tapes so that anyone excavating in the future hits this layer, well before hitting the electric cable!
Now we have heard that some garden office suppliers/electricians will run this cable along a fence or wall. This is obviously a much easier option than digging the trench, but we don’t advocate you take this route.
How much will I have to pay to connect my garden office to the mains?
We’ve been talking with our local electrician RGV Engineering about the costs involved in undertaking this hook-up. We asked them for a guide price to run an SWA sub-main cable rated at 45Amps buried in a trench, 25 meters from a garden office to the house.
They said they would expect the trench to be dug by others, before they arrive on site and that you would be looking at paying £1,000 plus VAT for a 25-meter run. This cost would include testing & certification.
So, you can see its not an insignificant cost! Your budget will be affected by the distance your garden office is located from the house. You will also need to budget for the digging of the trench.
If you are based in Wiltshire or Hampshire and looking for an electrician to connect the electrics in your garden office to the mains, we can recommend our friends at RGV Engineering.