How much does a ground source heat pump borehole cost?

Alongside heating efficiency, cost is one of the most common factors that comes up during conversations about ground source heat pumps. 

Drilling boreholes is perhaps one of the most substantial logistical and financial factors in these projects, and it has a big impact on the overall cost of installation. 

Below, we outline the costs associated with drilling boreholes, while also putting those costs in the broader context of ground source heat pump installation. 

The borehole itself

The cost of a borehole will depend on the depth of the borehole and how many boreholes need to be drilled. A general rough estimate to base your calculations on is around £50 to £70 per metre of borehole, which means that each 100m borehole will cost around £5000 to £7000. 

The number of boreholes you’ll need will depend on the heating requirements of your property, based on both the size of the building in question and how well insulated it is. 

Most homes will require between 1 and 3 boreholes, with an output of around 5 kW to 15 kW, which puts the borehole drilling cost at between roughly £5000 and £21,000. 

Other costs

You will also need to pay for surveys and to have the heat pump itself installed. To get the most out of the system and minimise the number of boreholes that need to be dug, many homeowners will choose to upgrade the insulation of their property. 

These additional costs, when added to the cost of the boreholes, result in an average total installation cost of £29,520. This is quite a substantial sum, but with gas prices constantly rising, the amount of time it will take to see a complete return on that initial investment is becoming shorter and shorter.

Government grants

Luckily, there are still a couple of government-funded financial incentives to help with the costs of installing a ground source heat pump. The standard grant that most people can access is worth £7,500, and until 31 March 2027, properties that are replacing oil or LPG heating systems can access £9,000.

This can substantially reduce the overall cost of installation, making it a much more feasible project for most homeowners. 

Savings

Most people investing in a ground source heat pump will be interested in how much they’ll save on heating costs. This figure will obviously depend on a number of factors, including the type of heating system that is being replaced, the size of the property, and how well it is insulated. 

For an average, well-insulated four-bedroom fully detached home, the average annual savings for an inefficient gas boiler will be £650, coming down to £130 for the most efficient gas boilers.

If you’re looking to insulate yourself from volatile energy costs that often go up but rarely go back down, while also reducing your carbon footprint, a ground source heat pump is an excellent option to go for. They do require a substantial up-front investment, but will continue to pay for themselves every year, especially as electricity prices go down and gas prices rise.