Sustainability in 2025: Optimizing Energy Labels and WWS Points with Renewable Partners

At Renewable Partners, we are committed to helping property owners make their homes future-proof. In a recent case in The Hague, we analyzed and optimized a property. With a current energy label F and 110 WWS points, the challenge was to improve energy performance and achieve the mid-range rental threshold, with a focus on cost-efficient measures and an optimal return on investment (ROI). Discover how we approached this and how we can help you make your real estate more sustainable.

Current condition of the property

The house initially had an energy label F, with an energy requirement (EP1) of 261.58 kWh/m²/year and a primary fossil energy consumption (EP2) of 364.98 kWh/m²/year. The heat requirement was high (267.25 kWh/m²/year), indicating significant heat loss due to poor insulation. With 110 WWS points, the property fell below the social rent threshold, with a maximum rent of €681.44 per month.

The analysis, carried out in accordance with the guidelines of NTA 8800, BRL 9500, and ISSO 82.1, showed that insulation was the highest priority, while the existing installations were relatively efficient. This formed the basis for our sustainability advice.

Objective: Mid-range rental and optimal ROI

Our goal was to optimize the property by improving both its energy label and its WWS point score, ideally to the liberalization threshold of 187 points. As this proved unfeasible, we focused on achieving the mid-rent threshold and maximizing ROI. We analyzed various sustainability and quality measures to develop a strategy that is both profitable and sustainable.

Sustainability measures

After a thorough analysis of the property and the possibilities, we recommended the following cost-effective measures:

1. PV panels: Installation of 6 PV panels (440WP, All-Black) on the flat roof to generate solar energy.
2. Facade insulation: Interior insulation of 59.78 m² of facades with Eurothane G (70 mm, Rc≥3.5) to minimize heat loss.
3. Decentralized heat recovery ventilation: Installation of a CO2-controlled decentralized heat recovery unit (Fresh-R Compac) for efficient ventilation.

These measures were selected because of their high impact on the energy label and the WWS point score, combined with a relatively low investment.

Results after sustainability measures

The proposed measures yielded impressive results:

• Energy label: From F to A+, a significant improvement in energy performance.
• WWS points: From 110 to 162 points, bringing the property to the mid-rent threshold.
• Maximum rent: Increased to €1,025.87 per month , an increase of €344.43.
• Investment: €13,160.91 (after deduction of ISDE and SVOH subsidies).
• ROI: An attractive 20%, excluding the increase in value of the property.
• CO2 reduction: A significant reduction in CO2 emissions, contributing to a more sustainable future.
• Property value: An estimated increase in value of €37,530

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