What should I budget for my energy-efficient renovations?

Correctly estimating the cost of renovations is sadly not an exact science. A great deal depends on your home and its current condition. If you’re looking to fully renovate a house with a poor EPC rating, you could end up spending as much as 125 000 euros.

If your home has already been totally – or at least partially – renovated, you’ll likely get good results from spending 20 000 euros on a heat pump with solar panels. We’d be happy to set out the different renovation options available to you and provide an estimate of the budget required.

On average, your home loses about 30% of its heat through the roof. Depending on the size of the roof and the type of insulation you choose (e.g., glass wool, polyurethane panels or cellulose wadding), you should budget between 5 000 and 12 500 euros.

Insulating and finishing your exterior wall can qualify as ‘major energy-efficient renovation work’ for which you can expect pay between 25 000 and 40 000 euros on average. You should always get proper advice on whether exterior wall insulation is a suitable and useful solution for your home.

There are a variety of different methods and materials you can use to insulate your floor. As always, it’s important to get the right advice to make sure you choose the most cost-effective option for you. It’s wise to set aside an average of 9 000 euros for this.

If you have an old house with single glazing, you should opt for high-efficiency glazing with an insulation value of around 1.0W/m²K or go for triple glazing with a value of up to 0.6 W/m²K. Once again, you should speak to an expert first. Given that the average house has around 30 m² of windows, you can expect to pay an average of 15 000 euros to replace everything.

Insulation not only reduces the amount of energy your home consumes, it also affects the indoor climate and air quality. If you’re considering installing a ventilation system, you should set aside between 5 000 and 10 000 euros on average.

If you want to replace your heating system, a condensing boiler costs an average of 7 500 euros. If your home has already been properly insulated, you might also consider installing a heat pump (air-to-air or air-to-water).

Heat pumps are energy-efficient systems used for heating and cooling buildings. They draw heat from the outside air or the ground to heat your home in winter and they reverse this process to provide cooling in summer. A heat pump can also be equipped to provide hot water. Your budget for a heat pump should be between 2 500 and 25 000 euros.

Tip: use KBC Brussels Mobile to easily request a quote for energy-efficient heating with the ‘Get a renovation quote’ service. This service is provided by our partner Impact Us Today.

When discussing heat pumps, it’s also worth mentioning heat-pump boilers. Unlike a heat pump, a heat pump boiler only heats your household water supply, using ambient heat and electricity to do so. This means the benefits of a heat-pump boiler are even greater if you also have solar panels. You should expect to pay around 3 500 euros on average for this type of boiler.

You can also heat your household water supply with a solar-powered boiler. In summer, your water is heated almost exclusively using solar energy. During the rest of the year, your solar-powered boiler will often rely on a condensing boiler or heat pump to keep the temperature of the water sufficiently high. This type of system costs between 2 500 and 8 000 euros.

If you’ve thoroughly insulated your home and you’re looking to install solar panels, you first need to make sure your roof is free of asbestos. You should also check the orientation of your roof to maximise the number of solar panels receiving direct sunlight. The total cost of installing solar panels is between 3 000 and 5 700 euros.

You may also be interested to know that the ‘Solar panels and battery’ service in KBC Brussels Mobile allows you to quickly and easily see how much you could save with solar panels and what it would cost to install them.

Some families that have solar panels also choose to install a home battery. If your solar panels generate more electricity than you consume, that power is stored in the battery to be used at times when the panels are producing less power. A home battery costing around 4 000 euros will typically be sufficient to meet the needs of a family with an average energy consumption of 3 500 kWh per year, but prices can go up to 10 000 euros for higher-capacity models.

The above figures give a rough indication of the prices you can expect if you decide to make energy-efficient improvements. If you would like to get a more specific breakdown, the ‘Calculate your renovation’ service in KBC Brussels Mobile allows you to easily work out your renovation budget and gives you an idea of the subsidies you’re entitled to. You’re welcome to run as many simulations as you like (free of charge and without obligation).

The convenience doesn’t stop there: if you download your renovation report, you can also use it to apply for your home loan at KBC Brussels, so you don’t have to get any additional quotes from contractors. It couldn’t be easier!

If you think you might need to stretch your budget further, be sure to check out what we can do for you with our different types of loans. Feel free to make an appointment with our experts – they’ll be happy to discuss your options and tell you what you need to keep in mind.

Instalment loan. Lender: KBC Bank NV, Havenlaan 2, 1080 Brussels, VAT BE 0462.920.226, RLP Brussels, FSMA 026256 A. Subject to your loan application being approved by KBC Bank NV.

The KBC Brussels Home Loan is a mortgage loan for immovable property. Lender: KBC Bank NV, with registered office at Havenlaan 2, 1080 Brussels, Belgium. VAT BE 0462.920.226, RLP Brussels, FSMA 026256 A. Subject to your loan application being approved by KBC Bank NV.