Animal-friendly insulation

You want to insulate your home. Did you know that small birds and bats often live under roofs and in cavity walls of homes? Often without you knowing it. In Wassenaar, for example, many bats live in older homes and these animals can then lose their homes or be killed. Bats are a protected species. There is therefore the possibility of insulating your home in an animal-friendly way. To do this, we create a species management plan (SMG). 

What is a species management plan?

A species management plan (SMP) is a plan by the municipality to properly protect protected animals and plants throughout the municipality. This is done on the basis of extensive ecological research. The SMP not only ensures the legal protection of vulnerable species, but also helps to sustainably conserve them. With this plan, the municipality can apply for an area-specific environmental permit from the province.

Aqua-Terra Nova survey of bats, house sparrow and swift

We started basic flora and fauna surveys of homes throughout the municipality in the spring of 2025. This is how we are looking at how many homes there are where animals live. You may see that this survey is being conducted in public spaces, near your home, business premises or garden. We are doing this survey so we know which animals (building-dwelling bats, house sparrows, starlings, swifts and house martins) are common in Wassenaar. Based on the results of the research, there is a possibility of animal-friendly insulation. See more information below,

Do you want to get started insulating your home in the coming period? 

Then there are the following options:

  1. You can insulate yourself if you first have an ecological study done and apply for a permit. This usually takes 8 to 12 weeks. Find a company for the ecological survey here. The method Nature-friendly insulation is unfortunately not allowed. Because the code of conduct Nature-friendly insulation has not been adopted.
  2. Animal-friendly insulation is not allowed because the rules for this are not yet ready.
    Then you wait to insulate until the animal-friendly process is established. After that, the process of animal-friendly insulation takes about 15 working days. We are currently in the process of preparing the SMP. Therefore, no isolation can be done under the SMP at this stage. We are investigating whether an alternative process can be allowed. As soon as the council knows, you will read about it on this page.

More information about insulation and what options are available in Wassenaar can be found on Custom Advice. 

Research in Wassenaar

Wassenaar Municipality will eventually start the surveys of the flora and fauna of homes throughout the municipality. This way we will see how many homes there are where animals live. You may see this survey being conducted in public spaces, near your home, business premises or garden. We are doing this survey so we know which animals are common in Wassenaar. This is the first step in making it easier for residents to have animal-friendly insulation.

This research may also need to be done in your garden. This occurs with larger gardens in or near estates and in villa neighborhoods. If this is the case, the homeowner will be notified by then. 

The surveys have thus begun. After about 3 years of preparation, the area exemption of the species management plan can be granted. 

Animal-friendly insulation

Insulating homes with birds and bats requires a flora and fauna permit under the Omgevingswet . You can apply for this yourself, but more and more municipalities in the Netherlands are applying for it all at once for all residents. This is called a species management plan (hereafter: SMP). The municipality of Wassenaar is also working on this. The province decides on this. During this period you can already insulate.

Frequently Asked Questions

I want to insulate now, What to do

You can insulate directly yourself, provided you have an ecological survey done beforehand and apply for a permit.

Why should I wait to insulate until the municipality has applied for an area permit?

The advantage of insulating under the granted area waiver is a shortened procedure of 15 working days. A regular permit process is 8 to 12 weeks.

Which animals in homes are involved?

Animals such as house sparrows, swifts or bats. The house sparrow is on the red list of endangered breeding birds. Swifts in the Netherlands also need more protection. Bats are a protected species under the Omgevingswet. 

Are bats or other animals in my home dangerous?

No, these animals are not dangerous. In fact, bats are useful. One bat eats about 1,000 mosquitoes per night. 

Why is animal-friendly insulation necessary?

Insulating homes is often desperately needed to save energy. In regular cavity wall insulation, the insulation company injects insulating material into the cavity. In the process, animals are often killed and their habitats disappear. Nature-friendly insulation combines Health for protected species and the preservation of homes.

What home insulation is involved?

It involves insulation of roof and (cavity) wall. Placement of a possible dormer falls under the same permit.

How does animal-friendly insulation work?

In animal-friendly insulation, the insulation company first allows the animals to fly away, a few days before the home is insulated. In addition, the company makes sure to provide replacement habitats for the animals. For example, bats are given a new residence in the cavity: the cavity shelter (see image(s). 

Is my house properly insulated with cavity housing for bats?

Yes, research done by the municipality of Utrecht shows that homes with cavity houses are still well insulated. 

Are there any other things I should consider if I want to insulate animal-friendly?

Good ventilation is important if you are only insulating the cavity wall - and not the roof. The insulation company can help you with this. It is also important that your exterior wall is in good maintenance condition. 

Want to get started with animal-friendly insulation yourself? 

Then you must go through several steps. It also includes some steps that need to be reported to us. See below the 3 steps:

Step 1. Report it to the municipality at least 5 working days before starting step 2 below with your permit number:
1. Have the cracks and holes of your home sealed.
2. Have verification that no species have been left behind. If present, coordinate with ecologist necessary.
3. Hang alternative habitats for the animals.
4. After completing steps 1 through 3 and after a minimum of 15 working days, you may start isolation.

Do not disturb or kill bats, house sparrows or swifts.
Let them fly out of your cavity wall or under the eaves yourself, with the help of an animal-friendly insulation company, after which the site is sealed off from flying animals by the insulation company (see illustration). 

Step 3. You must hang or install your own alternative habitats in advance of the insulation, such as the temporary bat box or the masonry bat box (see images). This is mandatory.

I am a housing cooperative

Housing associations can use the Requirements from the Aedes Code of Conduct for insulation.