ISDE subsidy for homeowners: how to approach it

The ISDE (investment subsidy for sustainable energy and energy saving) is the main national scheme for homeowners who insulate or switch to a (hybrid) heat pump. The amounts are worthwhile, but the scheme has conditions on which applications regularly fail.

What you can apply for

A single insulation measure receives a lower subsidy amount; combining two or more measures within 24 months earns the higher amount per measure. Combining literally pays.

• Insulation measures: roof, facade, floor and cavity wall insulation and high-efficiency glazing, with minimum areas per measure.
• Heat pumps, including hybrid variants alongside the boiler.
• Solar water heaters for domestic hot water.
• Connection to a heat network.

The rules that sink applications

You apply afterwards, no later than 24 months after installation, substantiated with invoices and proof of payment. The work must be carried out by an installation company; DIY work is not eligible for homeowners. Devices must be on the RVO code list, and minimum insulation values and areas apply per measure.

So keep all documentation: quotations, invoices, proof of payment and product specifications. The same documentation also helps the EP assessor give the measures full weight in a new energy label.

Start with a plan, not with an application

The biggest mistake is starting with the subsidy instead of the home. Which measure delivers most depends on the current state of insulation and installations. Sustainability advice maps this out, including the expected subsidy per measure, the costs and the payback time. That way you deploy the subsidy on measures that make the difference for your home, in the technically correct order.