Having work done to improve your home is more complicated when you're not the sole owner of the building. However, there are many projects to be considered and extremely interesting solutions available which would benefit all occupants.

Here are some ways of saving significant amounts of energy in a co-owned property.

1. Review your energy contracts

Before even considering having work done, it could be useful to take a close look at the energy supply contract for the communal areas. Did you choose the best supplier?

Why don't you consider collectively purchasing energy for private consumption by each co-owner?

2. Request a free energy audit

In Brussels, the Quick Scan from the Facilitateur Bâtiment Durable provides a free streamlined audit. It will objectively identify potential energy savings, which will help you to come to an agreement with your co-owners.

• For buildings containing 6 flats or more: e-mail facilitateur@environnement.brussels or call +32 (0)800 85 775.
• For co-owned properties containing fewer than 6 flats: contact Homegrade.

3. Insulate in order to reduce your energy use

Increasing the thermal insulation in the building is generally the most cost-effective solution. Prioritise the roof and then focus on the walls and window frames.

The cost of the insulation work can be split in different ways.

4. Think about replacing the boiler

In principle, replacing a (communal or personal) boiler which is more than 15 years old is a good idea. However, if it's a personal boiler connected to a communal chimney, you must be careful. 

You can also add a cogeneration device which produces heat and electricity for the existing boiler and keep the old boiler as a back-up (it will only be able to operate on a limited number of days per year) in order to prolong its lifespan.

5. Invest in solar energy

At the end of 2017, Brussels had more than 3,650 photovoltaic installations. However, there are still many exposed roofs that could have solar panels installed on them.

The advantage of solar projects on shared roofs is that not all of the co-owners need to be financially involved in the project. 

In addition, to help with these projects, Bruxelles-Environnement provides model contracts and minutes for co-owner meetings.

6. Find attractive financing options

Good news: in Brussels, energy grants partially finance work to improve the energy efficiency of buildings. What's more, the largest grants are those for co-owners.

Furthermore, there are other solutions for limiting the cost of the work. For example, some companies offer hire purchases of photovoltaic panels.

Thanks to European funding, the European project easyCOPRO provides assistance to co-owners in Brussels in developing and financing work to improve energy efficiency. This call for projects closed on 31 August 2018 and will make lessons that have been learned available to other interested co-owners (methodology, tools and more).

In order to go further

On the notaire.be website, you'll find a practical guide for co-owners, which is available to download.

Le Syndicat National des Propriétaires et Copropriétaires (the National Union of Owners and Co-Owners) and Engie Electrabel have also published a brochure entitled 'La copropriété, ses travaux et leur financement' (available in French).