A geothermal system in an existing house

May 23, 2019

As we’ve often said, it’s very possible to install a geothermal system in an already built house. What should you look out for before, during, and after installation? Here are a few things to consider.

Underground utilities

The contractor will have to dig around your house to install the underground loop for your geothermal system. There are probably a number of utilities already buried around your house. Electrical cables, water, and gas pipelines, sewers and the leach field are just some sites that must be known, so as to avoid when digging.

Surveying your lot is needed to establish boundaries, as well as locations, rights of way, and setbacks.

The electrical system and existing ducts

Since one of the benefits of geothermal energy is its low demand for electricity, it’s very possible that we don’t need to increase the electrical power in your home. However, it’s best to check first and make sure.

In the past, most residential electric heaters were designed to reduce the airflow needed to heat your home, reduce duct size, and reduce costs. But since more air must be circulated for a geothermal system to produce the same amount of heat in your home, your contractor may recommend that you change some air ducts to make the system sufficient for the necessary air flow.

Your system will then be more efficient, with less potential for problems caused by air noises.


Installing the ground loop for your geothermal system may cause some damage to your landscaping. A horizontal loop requires excavation work and digging around your house. You may have to cut down trees or shrubs to install the underground loop.

Location plan for the underground loop

According to CSA standards (the international standard for energy management in Canada), once your geothermal system installation is complete, you’ll need a plan to indicate the location of the underground loop.

This plan can be very useful when you (or a future owner) want to make changes to the landscaping, such as installing a decorative fountain or planting a tree. It’s recommended to place the plan in an envelope and keep it in a safe place.If you’re thinking of buying a home with a geothermal system, don’t forget to ask for this plan.

If you have any further questions about geothermal energy, please don’t hesitate to contact our team. We’ll be happy to answer you!