Research results: insulation | the floors (undersides) of gallery walkways and balconies, including upstands
- Commissie Duurzaam
- 29 jan
- 4 minuten om te lezen
Bijgewerkt op: 5 feb
Table of contents of insulation
The floors/walkways of the galleries and balconies are also the roofs of the galleries and balconies of the floors below. Therefore, they are referred to as roofs in the report. These walkways are also considered roofs in the SVVE subsidy scheme.
The floors (roofs) of the galleries and balconies
Research by students from Utrecht University of Applied Sciences showed that the upper floors lose heat internally because there is only 15 mm of insulation between the interior floor and the exterior floor of the balcony and gallery, causing cold to seep into the floor through the balcony.
This causes heat loss, higher heating costs, a greater chance of condensation and mould, and an uncomfortable indoor climate.
The concrete roofs/floors of the galleries and balconies are not insulated at all. Therefore, insulation is most effective here (see insulation - introduction ).
Roof insulation on those floors provides a concrete temperature difference for the homes below: in average Dutch flats, the indoor temperature can rise by 1.5 to 3°C with roof insulation while energy consumption remains the same.
This means that
homes under insulated galleries become noticeably more comfortable and warmer, especially in the winter months;
In summer, the insulation helps keep the outside temperature out, keeping it cooler inside during hot days.
Steeds Advies recommends applying roof insulation to the concrete walking surfaces of the galleries and balconies.
The target insulation value is Rc = 6.5 m²K/W, in accordance with new construction requirements. To prevent moisture problems and extend the structure's lifespan, a vapor barrier is applied. In addition, the Triflex BIS insulation system is used, which not only provides high-quality thermal insulation but also offers a durable and waterproof finish.
The uprisings
The upstands are the raised concrete edges from the floor to the frame. The thermal image below shows that, in addition to the brackets (top), the upstands also form a significant thermal bridge.
The insulation of these upstands was not addressed in any of the reports. The research by the HU and Steeds Advies did note that the connection between the gallery and balcony floors and the window frames was poor, causing drafts. However, no solution was provided for this problem.
Our own research shows that the upstands can be insulated in addition to the insulation of the balcony and gallery floors: if the liquid Triflex sealant is pulled up from the gallery floor against the upstand and around the frames , the seams and cracks are made waterproof and airtight.
Insulating the gallery floor itself provides greater energy savings than insulating the upstands, but including the upstands helps reduce cold airflow through gaps along sills and window frame feet, making the indoor climate more stable and limiting draughts.
Costs
Steeds Advies estimates the insulation costs at € 158,270, based on a m2 price of € 280.
Our own research indicated that:
for the Triflex BIS insulation €80-140 per m² for the floor;
for the upstand insulation €40-80 per linear meter;
These prices include installation and finishing but exclude VAT.
Marginal note
Due to the large difference in price quoted by Steeds Advies and the quoted research tool Perplexity , further inquiries were made as to the reason for this difference:
Difference compared to the advisor’s estimate (€280/m²)
Subsidy and National Heat Fund
(Read all about saving, borrowing and subsidies here).
The above insulation is only eligible for subsidy if the total surface area of the floors/walkways is more than 70% of the total roof surface (= main roof + floors, balconies and galleries).
The total floor area is roughly 25,472 m². According to a rough calculation, this is more than 70% of the total, and this measure is therefore eligible for a subsidy.
The subsidy amounts to:
for one insulation measure: €16.25 per m2.
for two or more insulation measures: €32.50 per m2.
For the limited surface area this amounts to 25,472 x € 16.25 = € 41,392.
The insulation can be further financed by a loan from the National Heat Fund.
Payback period for insulation with Triflex BIS
(highest prices, excl. VAT, without/with subsidy)
Marginal note
By using high-quality insulation with a waterproof finish, the protection of sealant joints and concrete is significantly improved. This leads to fewer sealant replacements and reduced maintenance costs (in 2024, sealant replacements cost €45,900 excluding VAT).
Want to read more about insulation?
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.