In short: the options at a glance

As part of its orientation phase, the Sustainability committee commissioned three studies to explore options for making Kleiburg phase 1 more sustainable.

The results of these studies are described in detail on this website. This page only contains a brief overview:

• where each topic links to the relevant page with more detailed information;

• intended as a tool to gain an overview of the total picture of possible sustainability measures for Kleiburg phase 1;

• and will raise questions and therefore contains all the links to the underlying articles and studies.

To compile this overview, Perplexity (our research tool) was asked 2 questions:

1. What is the most cost-effective sequence of measures for an apartment building like ours? This question included all proposals and recommendations from the preliminary studies.

2. Does combining sustainability measures with necessary maintenance have advantages and, if so, which ones?

1. The most cost-effective order according to Perplexity

IMPORTANT: Perplexity has provided the effective sequence and associated costs/benefits based on information collected on the internet regarding the sustainability of an EBA apartment building (built in 1973 , 11 floors, 110 apartments) in general. Therefore, the information is NOT directly applicable to Kleiburg. To obtain a Kleiburg-specific overview, a customized consultation is required.

The intention is that the future tailor-made advice will provide three packages of sustainability measures with the associated financial consequences. Based on this advice, the General Meeting (ALV) will decide whether and, if so, which package of measures can be implemented.

1.1. Roof, hydronic balancing and solar panels

• Roof insulation (from Rc 2.96 to 5.92 m²K/W over 2958 m²) offers immediate savings of 15-25% on block heating. Roof insulation is cost-effective for all apartments in a homeowners' association (VvE) building. Without proper roof insulation, warm air from the lower apartments rises via shafts, stairwells, and ventilation ducts to the roof, where it escapes unused – accounting for up to 25-30% of the total heat loss. Better insulation (Rc to 5.92) retains this heat and distributes it more evenly across the floors via lower return temperatures in the heating network.

• Hydronic balancing : 10-15% savings, €90 per apartment SVVE subsidy, and a direct reduction in monthly service charges; combine with replacement of the heat exchangers (Ferroli) due to potential financing from the National Heat Fund.

• Solar panels (approx. 100-200 kWp on roof, aimed at 50-100 MWh/year for elevators/lighting/boiler/hydrophore.

These measures deliver the highest savings per euro and a strong base position for VvE subsidies.

Note: An additional advantage of roof insulation and water-side balancing is that the heating pipes are less stressed, resulting in less wear and tear and leaks.

1.2. WTW heat pump

A heat recovery heat pump on the 10 roof fans recovers heat from the air at approximately 21°C and increases the temperature of the return water from the district heating system before Vattenfall brings it back to approximately 65°C.

Addition:

• The WTW heat pump makes the above measures (see 1.1.) more attractive, but does not replace them.

1.3. Gallery/balcony floors, ground floor and console cladding

Floor insulation of gallery/balcony including upstands/frames and bracket cladding to prevent cold bridges: 10% savings and increased comfort;

Addition:

• Ground floor floor insulation only if specific conditions are met.

• These are cost-effective measures, but with a slightly lower saving per euro than roof + water-side adjustment and WTW

• Floor insulation is more important than console cladding due to higher savings (15-20% vs. 3-5%), a wider range of comfort, and better subsidies. Console cladding is valuable but secondary.

1.4. Sodium-ion batteries, ventilation grilles and CO₂-controlled ventilation

Regarding the batteries :

• for the meter in the bend: given the high consumption with evening peaks (lifts, lighting, pumps) and continuous load (hydrophore, fans), a battery is very cost-effective and strongly recommended;

• for the meter in the head: given the consumption in the evening, energy storage is useful and potentially profitable.

Regarding ventilation grilles: read the insulation pages and ventilation ;

Regarding CO₂-controlled ventilation: read the ventilation page .

1.5. Facade/cavity wall insulation behind concrete panels

Rc 0.83 to 1.5/2.4 (for facade with 20% panels and 80% glazing H R++) , highest investment but suitable for completing the insulation of the shell.

1.6. Benefit, savings, costs and returns

2. The benefits of combining necessary maintenance with sustainability

Besides sustainability, the VvE is responsible for two urgently needed maintenance measures (see also our MJOP):

• 2.1. concrete damage repair;

• 2.2. replacement of the heat exchangers.

SVVE/SEEH+ only subsidizes energy measures (roof, floor, and facade insulation, heat recovery (HRV), and water-side balancing), not regular maintenance such as concrete damage repair and exchanger replacement.

But combining this necessary maintenance with sustainability measures can yield significant financial benefits.

2.1. Combining concrete repair with sustainability

Concrete damage repair is not directly eligible for subsidies such as SVVE, nor for a loan from the Warmtefonds.

However, there are indirect subsidy benefits through combination:

1. Halve scaffolding and mobilization costs (40% savings);

2. The SVVE package bonus (for more than 3 measures) provides a 30-50% higher subsidy; the package bonus also applies without concrete repairs. However, the combination provides 2.6 times the financial benefit due to implementation costs (scaffolding/mobilization).

If concrete repair is necessary, combining it with other measures would yield a 67% advantage.

2.2. Combination of heat exchanger replacement with sustainability

Replacing the exchangers (our Ferolli's) ourselves

• receives no subsidy ;

• but enables package formation so that other measures yield 62% more SVVE.

This is the smart financial leverage of combining MJOP with sustainability.

The latest heat exchanger models have a built-in flow restrictor and temperature controller. This allows for 100% centralized adjustment. With our current exchangers, 40% of the adjustments must be done manually in the apartments.

Replacing exchangers from 2013 with new ones reduces the costs of hydronic balancing by 40 to 50%.

In addition, the replacement of the exchangers (2013→2026) + dynamic water-side balancing would be a recognized sustainability measure with 15% savings on the amount of heat (GJ) that the apartment building takes from Vattenfall via the heating network due to more efficient operation of the system.

Perplexity concludes that replacement of the exchangers in combination with the dynamic adjustment would be 100% financeable through the Warmtefonds VvE Energy Saving Loan .

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Do you have any questions, ideas or would you like to share your experiences?

Email us at duurzaamkleiburg1@gmail.com . Together we'll chart a path toward a future-proof Kleiburg.