Housing

5 February 2019

Renovating your house: how to save energy and money

Are you about to renovate your house? And would you like to help the environment and your wallet at the same time? Find out how.

What is an ecological renovation?

If you're looking for a way to consume less fossil fuels, such as natural gas or oil, this is called an ecological renovation. By doing one, you can reduce your ecological footprint and gain financial benefits.

The advantages of an ecological renovation

Ecological renovations are usually more expensive than standard renovations, but in the long term, the energy savings far exceed the original investment. 

How profitable are solar panels?

You pay around 5,000 euros for the installation of 14 photovoltaic solar panels on the average family home. You save around 850 euros on your energy bills each year. In Flanders you have to deduct the prosumer fee of 350 euros per year from that. Taking into account the evolution of energy prices, in Flanders you would earn your investment back within 10 years. In Wallonia within 9 years and in Brussels itself within 6 years. Depending on the region you live in, the average return on your solar panels is 8 to 10% over a minimum of 25 years. An ecological renovation is therefore much more profitable than a savings account.


Ecological renovations make it possible to reduce a household's consumption of primary energy sources. That counts towards the energy performance certificate (EPC), a useful instrument used to determine and compare a building's energy consumption. Increased efficiency ultimately increases the value of your house.

"In the long term, the energy savings far exceed the original investment."
The different stages of an ecological renovation

Well-targeted actions improve the thermal comfort of your home and ensure you save energy. A few ways to get started and to optimise your (financial) efforts.


1. Insulation: the most important step

Before you install any new devices, it is particularly important to improve your home's thermal performance. That way, you will reduce consumption from your heating so that it won't cancel out any future savings.

This is about insulating your home efficiently to avoid heat-loss caused by air circulation or a lack of air-tightness.


  • Limit heat-loss caused by circulation: ensure there is good air-tightness in the outer shell of your home with well-insulated, thick walls, roofs and floors, but also with good window frames, in which you can place three panes of glass. Also, reduce thermal bridges (where the insulation layer is breached), particularly at contact points between the walls, floors, roofs and window frames.
  • Limit losses due to a lack of air-tightness: seal cracks and gaps properly.
2. Efficient heating

Once you have insulated your home you have various options for efficient heating: thermal solar panels, a heat pump, a wood-fired boiler or wood burner, or a wood-pellet-fuelled burner with a high efficiency rating.

3. Renewable energy

Renewable energy is the current trend: green electricity and biofuels. Be sure to look into whether installing a solar boiler, a biofuel boiler or burner, or a heat pump could benefit you.

How can you finance your ecological renovation?
Green loans from your regional government

All three regions support ecological renovations. They subsidies loans with very low interest rates for their residents. To be eligible for one of these loans, your income must be below a certain threshold and there are conditions regarding the nature of the work you want to carry out. So take a quick look at your region's website.

Support from banks

Some financial institutions also support these environmentally-friendly initiatives by offering attractive interest rates for renovation loans. Make sure the work you want to carry out fall within the ecological renovation category, as stipulated by your bank.

An example: a loan for the installation of photovoltaic solar panels

Let's return to our earlier example:

  • You pay around 5,000 euros for the installation of 14 solar panels on your roof.
  • If you chose to take out a loan with ING over a 3-year term, at a fixed interest rate of 1.95%, you would pay back 143.06 euros per month.
  • Even if you live in Flanders and you have to pay a prosumer fee, you would still save 500 euros on your energy bill. In 5 years, that's as much as 2,500 euros, which greatly exceeds the interest costs paid. With this annual saving you would therefore quickly earn your investment back.


So, thanks to the right loan, you would get a positive return. If you live in Brussels or Wallonia, your return would of course be even greater.

To sum up

An ecological renovation allows you to reduce your footprint and save at the same time. Your house will also increase in value.


Now you have everything you need to finance your ecological renovation.


Article written in association with TopCompare.be (FR).