Window Frames & Sliding Doors
Custom uPVC window frames,
expertly installed.
Schüco window frames, doors and sliding doors for a more comfortable, more energy-efficient home.
Products
Our solutions
From a single window frame to a complete rear facade. Kozenta helps you from first idea to installation.
Our approach
Why Kozenta?
01
Made to measure
Every window frame is tailored to your home and wishes.
02
Schüco quality
We work extensively with high-quality Schüco systems.
03
Personal advice
No standard solution, but advice that fits your situation.
04
From advice to installation
One point of contact for the entire process.
Warranty & aftercare
What you get exactly after installation
No vague promises: this is stated clearly in your quote and your invoice.
10 years on the window frames
On the PVC profiles, colour fastness and shape stability of the Schüco system.
10 years on the glass
On the insulating glazing against cavity leakage and condensation between the panes.
5 years on the installation
On the fitting, sealing and finishing work carried out by our own installers.
Service after completion
Does a window not close smoothly after six months? Call us and we'll come adjust it. Free of charge within the warranty period.
Installation by our own fitters, no subcontractors. The same people who come to measure also install your window frames and return for service.
Systems
Quality begins with the profile.
At Kozenta we work extensively with Schüco. This means we choose high-quality systems that combine design, comfort, insulation and safety.
Schüco Living 120
Our most insulating PVC system. With a 120 mm installation depth, a multi-chamber structure and three continuous seals, there's room for extra thick triple glazing. That gets you insulation values reaching passive house level — ideal for new builds, sustainability upgrades and large glass surfaces.
- 120 mm installation depth, extra-deep multi-chamber structure
- Uf value down to around 0.8 W/m²K
- Room for triple glazing up to around 52 mm
- Three continuous seals against wind, cold and moisture
- Sound insulation up to around 47 dB
- Suitable for passive builds, new builds and large elements
Schüco CT 70
A versatile five-chamber system with 70 mm installation depth that forms the basis for window frames, doors and sliding doors. The most chosen Schüco system for home renovation: strong insulation, high security and a long lifespan.
- Five-chamber system with 70 mm installation depth
- Uf value between around 1.2 and 1.5 W/m²K
- Double EPDM seals against cold, moisture and wind
- Sound insulation up to around 48 dB
- Burglar-resistant according to RC2
- White, cream and foils in colour and wood-grain structures
ISDE subsidy 2026
Save on insulating glass with subsidy
The following ISDE amounts apply to standard owner-occupied homes in 2026. Kozenta processes this directly in your quote.
How much subsidy can I get?
Only the actual glass surface counts; minimum 8 m² per home.
Estimated ISDE subsidy
€ 2.220
20 m² × € 111 per m²
Quote with subsidy calculation
Indication based on the ISDE amounts for 2026. You apply for the subsidy yourself at RVO with DigiD; we provide the specifications and invoice details.
HR++ glass
€25
per m² of glass surface
HR+++ / triple glazing
€111
per m², including window frame replacement
Doubling rule
2x
when combined with a second measure within 24 months (heat pump, solar water heater or district heating)
Key conditions
- You are the owner-occupier of an existing home (not new-build or a rental).
- At least 8 m² of glass replaced per home; only the actual glass surface counts.
- HR++ glass must reach a U-value of at most 1.2 W/m²K, triple glazing at most 0.7 W/m²K.
- For the higher amount of €111/m², glass and window frame must be replaced together — exactly what we deliver as standard.
- Submit the application within 24 months of the last works, with invoice and proof of payment.
- Have the work carried out by a construction company or installer; installing it yourself does not qualify for subsidy.
Example calculation
A living room and bedrooms with a total of 20 m² glass in new Schüco window frames:
- 20 m² HR++ glass
- €500
- 20 m² triple glazing + window frames
- €2.220
- Triple glazing + second measure within 24 months
- €4.440
How we arrange it together
- 01
On-site survey
We measure your window frames and determine the exact glass surface in m².
- 02
Glass advice
HR++ or triple: we calculate the cost, savings and subsidy amount.
- 03
Quote with specification
Your quote states U-values, m² and window frame type — ready to use with RVO.
- 04
Installation and invoice
After installation you receive an invoice with all details needed for your application.
Quote with subsidy calculation
Amounts apply for 2026 and may be changed by RVO. Kozenta provides the measurements, glass specifications and invoice details you need for your application; you submit the application yourself with RVO using DigiD.
Pricing
What do new window frames cost?
Indicative starting prices including installation, so you know what to expect before requesting a quote. You'll receive a first tailored price indication within 1 business day.
- Fixed window
- from € 495
- Tilt-and-turn window
- from € 745
- Front door
- from € 1,850
- French doors
- from € 2,950
- Lift-and-slide door (2-panel)
- from € 4,750
per unit, incl. HR++ glass and installation
per unit, incl. HR++ glass and installation
incl. security hardware and installation
incl. glass and installation
incl. HR++ glass and installation
Whole house, on average
€ 9,500 – € 24,000
Terraced house with 10 to 16 window frames, including glass, installation, finishing and removal of the old material. Prices incl. VAT (reduced rate for homes older than 2 years).
Indicative starting prices including installation and VAT. The final price depends on dimensions, colour, glazing and the on-site situation. After on-site measuring you'll get a fixed price with no surprises.
Get my price indicationOrder process
From first idea to installation.
A clear process with a single point of contact, from the first request to completion.
- 01
Request a quote
Tell us what you'd like to achieve.
- 02
Personal advice
We discuss your wishes and options.
- 03
On-site measuring
The dimensions and situation are checked.
- 04
Final design
You receive the final specifications and quote.
Projects
Recently completed
Window frames, doors and sliding doors at homes in the The Hague and Rotterdam region.
Customer reviews
4.8/5 from 87 Google reviews
What customers write about the advice, the installation and the aftercare.
“Had the whole house done. Neatly installed, everything finished within two days and left completely clean. The installers were Kozenta's own, you can tell from the finish.”
Whole house, 14 window frames + sliding door
“Clearly explained upfront what was and wasn't possible. The quote was accurate to the euro and we could submit the subsidy application straight away with their invoice.”
Rear facade replaced with lift-and-slide door
“The house is much quieter and warmer. After three months one window was a bit stiff to close; within a week someone came by to adjust it. No hassle at all.”
8 window frames with triple glazing
“Good advice on the hardware. A bit pricier than the cheapest quote, but the quality and communication were worth it.”
Front door and side light
Showroom
Visit our showroom
See our window frames, doors and sliding doors in real life. Make an appointment and we'll take all the time to advise you directly using our Schüco window frames, doors and sliding doors.
Kozenta Showroom
Phillipstraat 40, Zoetermeer
Why visit?
- See and feel the difference between Schüco Living 120 and Schüco CT 70.
- See all colour and finish options in real life.
- Personal advice from our own advisers, with no obligation to buy.
- Get an immediate indication of the options and investment for your situation.
Not sure yet what you need?
Answer a few short questions and discover which solution best suits your home.
Ready for new window frames?
Tell us what you'd like to change. We'll think along with you and help you find the right solution.