Air Cavity Maximise air cavity for insulation against noise, thermal or both.

Magnetic Seals Create airtight seals, similar to your fridge doors to eliminate noise and draught

Acrylic Glazing 6 times more thermally efficient to keep your home or office cool in summer and warm in winter

A Practical Double Glazing Solution for Sliding Windows in New Zealand Homes

Many New Zealand homes still have single-glazed sliding windows that let in noise and allow heat to escape. For these properties, replacing entire window units can be costly, disruptive, and often requires significant structural work that can affect the look and function of your existing sliding windows.

Magnetite provides an innovative double glazing solution for sliding windows - without the need to replace your existing frames or hardware. Our retrofit system is installed from the inside, making it ideal for sliding windows throughout the home, including living areas, bedrooms, and hard-to-access locations.

With over 25 years of experience, Magnetite delivers proven results with up to 70% improvement in insulation and noise reduction. Our team assesses your sliding windows, designs a tailored solution, and installs it with precision - all while keeping your home's exterior completely untouched.

We work with a trusted network of licensed estimators, fabricators, and installers across Aotearoa, primarily throughout the North Island.

Request a Quote

Advantages of Double Glazing Sliding Windows in New Zealand Homes

Double glazing sliding windows offers a range of benefits for New Zealand homeowners looking to improve comfort without the cost of full window replacement. It improves thermal comfort, lowers energy use, and significantly cuts down on external noise - all while retaining the convenience and functionality of your existing sliding window system.

Magnetite's award-winning retrofit double glazing system is designed to work with existing sliding window frames, including aluminium and timber. It's the perfect solution for homes where replacing sliding windows would be costly or disruptive. Save time, reduce waste, and enhance your home's comfort by retrofitting instead of replacing.

Noice Reduction

Thermal Comfort

Energy Efficient

Fits Existing Windows

How green home loans work

Start with the project quote, then confirm eligibility directly with your bank.

1

Get a Magnetite quote Book a free in-home measure and quote. We will assess your existing windows and recommend the most suitable solution.

2

Check with your bank Ask whether your Magnetite glazing project qualifies under the bank's current offer.

3

Apply before work begins The bank may need a valid quote and installation date. Obtain approval before paying for or completing the work.

4

Confirm installation Once finance and the project are confirmed, Magnetite will arrange professional installation.

Proven Results

Our window systems have been independently tested by the National Acoustic Laboratories in line with National Fenestration Rating Council (NFRC) regulations. Reduce up to 70% of noise through windows or doors with Magnetite secondary glazing solution.

View Noise Reduction Technical Data

Our window systems have been independently tested by the Window Energy Rating Scheme (WERS) in line with National Fenestration Rating Council (NFRC) regulations. Improve up to 70% of thermal efficiency of your windows or doors with Magnetite secondary glazing solution.

View Thermal Improvement Technical Data

How Magnetite Works

Installation of a discreet Magnetite subframe allows a clear optical grade acrylic panel to attach inside the existing villa windowsill, using continuous magnetic channels to ensure a secure and airtight seal. The magnetic seal ensures that when the Magnetite panels are in place, this villa double glazing system has the lowest air infiltration rate of any operational window. This seal creates an air cavity between the villa's existing windows and your Magnetite panels.

What If You Could Upgrade Your Windows Without Replacing Them?

Magnetite is a retrofit secondary glazing system installed on the inside of your existing windows, creating an additional insulating air cavity between the existing glass and the Magnetite panel.

That extra layer can improve both thermal and acoustic performance, while allowing you to retain the character and appearance of your existing windows.

Your existing windows stay. Their performance changes.

See If Magnetite Will Work in My Home →

Why Homeowners Choose Magnetite for Double Glazing Sliding Windows

Acoustic & thermal insulation

Our secondary glazing system is customised for each project and delivers excellent noise control and thermal efficiency. It's independently tested to reduce noise and heat loss by up to 70%, which is especially beneficial for sliding windows facing busy streets or exposed to the elements.

No structural changes or exterior alterations

Our system is installed entirely from the inside, making it perfect for sliding windows where preserving the exterior appearance and existing frame is a priority. It maintains the look and function of your sliding windows without any external modifications.

Increase in property value

Retrofitting your sliding windows with double glazing boosts comfort and energy efficiency, helping to improve resale value and reduce ongoing heating and cooling costs.

Sustainable solution

By enhancing thermal performance and reducing reliance on heating or cooling systems, our double glazing sliding windows solution lowers energy consumption and greenhouse gas emissions. Using your existing windows also means less waste and a smaller environmental footprint.

Custom installation

Magnetite's retrofit double glazing is compatible with a wide range of sliding window types and sizes found in New Zealand homes, including single-panel, double-panel, and multi-track configurations. Our systems are custom-fitted to ensure a seamless finish.

Hear From Some Happy Magnetite Customers!

“I’m super impressed with the product and install! Awesome product, I will be recommending to anyone that will listen. Thanks again for being so easy to deal with, and getting it done so quickly.”

Rachel

“I am thrilled with my ‘new’ windows & can honestly say ‘it’s the best investment I’ve made in my house”

Judy

“Already we think the sound difference from these windows is going to be genuinely life changing!”

Strahan

“I love the double glazing!! Thank you for a great job.”

Wendy

“I’ve noticed such a huge difference with the new windows. That room is warm and even this morning when the master was covered in condensation, there wasn’t a single drop on the nursery windows! Super impressed!”

Rhonnie

Thank you and your staff for being so honest and professional with our dealings. I can honestly say it has made a huge difference in the noise production. My husband is a shift worker and sleeps alot during the day and he has found it to be very good at blocking out the outside world.”

Colleen

Excellent to communicate with and delivered as promised. Lovely people and would happily recommend.

Daniel

I noticed a huge improvement immediately from being very cold, damp, noisy, dusty and then heat and curtain damage from the incoming UV rays to being comfortable and generally better health.

Carolyn

Ryan and his team have been awesome, I highly recommend Magnetite and their system to retrofit secondary glazing on older homes.

Maree

Compare green loans for window glazing

These New Zealand bank offers explicitly include double glazing or secondary glazing. Terms can change, so check the linked bank page before applying.

Loan	Published offer	Initial term	Window glazing eligibility
Good Energy Home Loan	Up to $80,000 at 1% p.a.	3 years	Double, secondary or triple glazing
Better Homes Top Up	Up to $80,000 at 1% p.a.	3 years	Double, secondary or triple glazing
Better Future Home Loan Top Up	Up to $80,000 at 1% p.a.	3 years	Double, secondary or triple glazing
Greater Choices Home Loan	Up to $50,000 at 0% p.a.	5 years	Double glazing.

Published offers checked on 30 September 2026. Rates, limits, eligibility and fees may change without notice. Lending criteria, equity requirements, terms and conditions apply. At the end of a special fixed period, the bank’s applicable standard or floating rate may apply. Contact the bank or a licensed financial adviser before making a borrowing decision.

Before You Replace Your Windows, Compare Your Options.

Existing windows retained
Added insulating air cavity
Designed for noise reduction
Thermal improvement
Major structural replacement
Maintains existing window appearance
Suitable for many existing homes

Standard window replacement

Usually no
Depends
Depends on specification
Depends on specification
Often required
Not necessarily
Varies

Megaseal retrofit

✓
✓
✓
✓
Usually not
✓
✓

You may not need to replace a good window to get a better-performing one.

Magnetite retrofit solutions can provide thermal and acoustic benefits for many existing homes in Auckland.

Get My Free Measure & Quote →

Window Installation for Auckland Homes

Auckland homes face a unique combination of cool winter mornings, moisture, busy roads and increasingly dense neighbourhoods. That means the right window solution is not simply about appearance. Magnetite works with homeowners across Auckland who want to improve:

Cold bedrooms

Make rooms more comfortable during colder months by improving the thermal performance of existing windows.

Road and traffic noise

Reduce unwanted sound entering homes near busy roads and urban areas.

Apartment noise

Improve acoustic comfort where neighbouring properties, streets or commercial areas are close by.

Older Auckland homes

Upgrade window performance while retaining existing joinery where appropriate.

Condensation-prone rooms

Improve the internal glass temperature and address one of the factors that contributes to condensation.

Talk to an Auckland Window Specialist →

Proven Window Performance

Up to 70% Noise Reduction

Our window systems have been independently tested by the National Acoustic Laboratories in line with National Fenestration Rating Council regulations.

View Acoustic Test Results →

Up to 70% Thermal Improvement

Our window systems have been independently tested to the Window Energy Rating Scheme requirements.

View Thermal Test Results →

From Cold or Noisy Windows to a More Comfortable Home.

01

Tell Us About Your Windows

Send us your details and what you want to improve.

02

Free Measure & Quote

We assess your existing windows, take measurements and discuss suitable options.

03

Your Solution Is Made to Fit

Magnetite panels are measured specifically for your windows.

04

Professional Installation

Our installers fit the system with minimal disruption to your home.

05

Enjoy the Difference

A warmer, quieter and more comfortable space.

Book My Free Measure & Quote →

What You’ll Need to Apply

To qualify for a green home loan, banks typically require:

An active home loan with the bank (or approval to transfer your mortgage to them).
Sufficient equity in your property to meet standard lending criteria.
A formal quote covering the supply and professional installation of your Magnetite system.
Project documentation, including a proposed installation timeline and any extra details requested by your bank.
Prior approval, before paying for or commencing any installation work.

Request a Free Quote →

Don’t Spend Thousands Replacing Windows Until You Know Whether They Actually Need Replacing.

A full replacement might be the right answer. But depending on your existing windows and what you are trying to fix, there may be another option. Before making the decision, find out:

Whether your existing frames can stay
Whether your existing frames can stay
Whether your existing frames can stay
Whether your existing frames can stay
Whether your existing frames can stay

Get a Free Window Assessment →

Green loan frequently asked questions

A green loan is finance intended for eligible upgrades that improve a home’s energy efficiency or environmental performance. In New Zealand, these are commonly structured as special-rate home loan top-ups for existing mortgage customers.

Yes. Many New Zealand banks currently list double glazing as an eligible upgrade. Approval depends on the lender and your circumstances.

Magnetite provides professionally supplied and installed retrofit double glazing and secondary glazing, and both double glazing and secondary glazing are listed by ANZ, ASB and BNZ among eligible window upgrades. Your bank must confirm that your specific project and application qualify.

No. Magnetite fits retrofit double glazing or secondary glazing to your existing windows or doors. This can improve insulation and comfort without removing the original window system.

That depends on your existing mortgage, equity, borrowing needs and repayment plans. Compare the interest rate, loan limit, fixed period, fees and the rate that may apply after the special term.

The remaining balance may move to the bank’s applicable standard or floating home loan rate, or you may be able to refix it. Check the current product terms with your bank.

Usually, yes. Banks commonly ask for a valid quote from a professional supplier and installer, and some also ask for an installation date.

No. Magnetite does not provide credit or financial advice. We provide the glazing assessment, written quote and installation information. You apply directly through your bank.

Is Magnetite Right for Your Windows?

It may be a good fit if:

Your existing window frames are still in reasonable condition
Your rooms feel cold near the windows
Outside noise is disrupting your home
You experience window condensation
You want to retain the appearance of existing windows
You are exploring alternatives before completely replacing your windows

It may not be the right solution if:

Your frames themselves require major structural replacement
Your project requires completely new window openings
Another window system is more appropriate for your property

Not sure? That is exactly what the free assessment is for.

Ask Magnetite About My Windows →

Choosing a Window Installer in Auckland: What Should You Look For?

Not all window installations solve the same problem. Before comparing quotes, understand exactly what you are paying to change.

1

Decide what you want the window to improve

Appearance? Warmth? Noise? Condensation? All four?
2

Ask whether full replacement is necessary

If the existing joinery is sound, alternative glazing systems may be available.
3

Compare window performance, not just price

Two windows that look similar can perform very differently acoustically and thermally.
4

Ask for evidence

Look for independently tested thermal and acoustic performance rather than relying solely on marketing claims.
5

Understand exactly what is being installed

Ask how the glazing works, what happens to your existing windows and what ongoing maintenance is involved.

Frequently Asked Questions

The cost depends on the size, number and style of your windows and the solution required. Magnetite provides a free measure and quote so your options can be assessed properly before pricing is confirmed.

Not necessarily. Magnetite is a retrofit secondary glazing system designed to work with many existing windows.

Improving glazing performance can reduce heat transfer through your windows and improve comfort around them. The actual result depends on the property and glazing system.

Certain glazing systems can substantially reduce noise transmission. Magnetite states noise reductions of up to 70% under tested conditions.

Magnetite provides retrofit secondary glazing solutions in Auckland. The system creates an additional glazed layer inside the existing window rather than necessarily removing the original window.

Improved glazing can increase the internal surface temperature of the window, addressing one factor associated with condensation. Moisture levels and ventilation also affect condensation.

This depends on the size and scope of the property. Magnetite can provide an expected installation timeframe after measuring and assessing the windows.

[Insert Magnetite’s actual Auckland service areas.]

Need Windows? Make the Upgrade Count.

If you’re already thinking about replacing or upgrading your windows, take five minutes to find out what else they could do for your home.

A Magnetite specialist can assess your existing windows, explain your options and provide a free measure and quote.

No obligation. Just a clearer idea of what your home actually needs.