EVS Window Technology

Great solutions for character homes
that keeps the good stuff in and the bad stuff out. 

EVS is a new and better way to enhance character windows

Hi, You can get triple glazing on your older character home and enjoy the benefits of warmer dryer windows! E V S Window technology can deliver highly insulated panels that lead in performance and maintain the character of your heritage windows. Tested, approved, and rated above the new glazing standards, EVS delivers the best value retro glazing system that will save on costly heating and keep your home comfortable. Call us now for a free home glazing appraisal and quote!

Great Performance

EVS is a high glazing system that performs well across every level, from leading thermal insulation values to enhanced durability that protects your existing timber framed windows.

Simple Application

EVS glazing is a simple process, makes installation quick and easy, saving time and money on your retro glazing project. Home owners can save even more by DIY installation.

Retain Character

EVS maintains the character of homes that have beautiful features such as delicate astragals, coloured glass and leadlight windows. See how different home owners have upgraded their homes with before and after images to compare.

Fights Moisture

Condensation is the most damaging aspect of single glazing because of the unhealthy dangers of mold and the destruction caused by rot. EVS eliminates over 90% of your window condensation making for a healthier, warmer home.


100's of homes are upgrading to triple glazing and retaining their character windows

Checkout our latest newsfeed posts!

All new glazing technology that protects and enhances character windows 

Now there is another option for retro glazing that delivers better value!

The secret to achieving high performance at more affordable prices, is by retaining the existing glazing which reduces installation costs and increases the glazing cavity for extra insulation.

Unique EVS Technology allows windows to breath, removing moisture to maintain warm and dry windows and provide protection against damaging condensation and mould.

EVS Retro Glazing provides greater protection to older character windows that are exposed to the elements by providing a durable protective uPVC cover frame with integrated double seals that prevent moisture reaching the old putty and glass. This uPVC wont rot and can be painted to blend into the existing colour scheme, adding to the character detail of the original windows.

All new Patent Pending Technology
is a totally new glazing system that is designed to fit externally to existing timber windows. EVS’s unique patent pending technology allows trapped moisture to be vented, while providing increased thermal insulation and protection. EVS has the performance of triple glazing but at more economical prices than double glazing. Installation is a lot quicker and easier than traditional retro fitting double glazing to timber windows, which saves money and time.

PVCu insulation and protection
The latest EVS profiles are made from PVCu which can be painted to match your existing timber paint finish. The PVCu profiles provide increased weather protection to the vulnerable putty edges as well as increased the thermal layers to reduce heat loss. The attractive EVS profile adds further character to your existing timber frames.  

    EVS Glazing protects windows from forming condensation that causes mould and rot. EVS has a triple layer of that allows the inside panel to stay warmer and reduce the dew-point condensation forming.
    Old single glazed windows allow heat from the inside to escape. EVS Glazing units provide double air spaces to reduce heat loss and maintain warmer windows. EVS in conjunction with high performance low-E glass can provide of the highest insulation values (R-0.59) for retro glazed timber windows.
    EVS offers the increased noise protection of three layers. Additional noise protection can be achieved with draught stop and sealing the gaps around the frames.
    In most cases EVS triple retro glazing is a faster and easier product to install which can reduce the time and cost. This can provide customers with more affordable glazing options compared to double retro glazing.
    EVS is made from PVC-u which is a very robust rot free material. The PVC-u Glazing unit is fixed over old timber and seals off most of the exposed timber and old putty, preventing future degradation and leaks .
    EVS utilizes your existing glass and timber frames so you don’t have to destroy your existing windows or replace the glass that would otherwise be sent to land fills .
    EVS endeavors to make your new glazing blend with the old by being finished with a hand painted colour that matches the existing window frames. The hand finished paintwork has its quirks that help retain their original character rather than a soothe plastic machine finish that new replacement windows can provide.

EVS High Performance Retro Glazing

Higher performance EVS means less heat loss with warmer dryer windows 

Heat Camera demonstrates heat loss.

These images show the heat map from the EVSx3 fixed to the bottom windows and the single glazing along the top windows. The red colour indicates higher heat loss and the yellow indicates better insulation with less heat loss. The EVSx3 panels maintain a similar temperature to the surrounding timber frames, demonstrating how effective EVSx3 is at providing a high performing thermal protection. (Just a note about the red on the middle EVSx3 panel, is a reflection of the heat from the photographer, not heat loss from within the home)

Temperature Comparison Test

Temperature readings from  around a home with different glazing systems. EVSx2 performs well above standard Double Glazing and just below top of the range Xcel glazing. Please note that this test was undertaken by EVS and has not been independently varified. EVS is in the process of getting independent BRANZ testing done, and their results will be made available when they are completed.  

Over 90% reduction in condensation!

These windows were photographed part way through the EVS installation process and record the dramatic improvement of condensation reduction compared to the single glazing panels. Condensation can be totally eliminated by using adequate ventilation systems, but EVS helps to reduce the damaging effects of condensation and moisture from your windows through increased thermal performance.

EVS product and workmanship 10 Year Guarantee

Your timber windows are vulnerable to the affects of weather particularly around the putty and glass junction. These areas are the first to fail with water and sun acting on these delicate edges and opening up cracks where water can penetrate.

EVS provides a greater level of protection by encapsulating the vulnerable putty edges and keeping water and damp away. EVSx3 goes even further to protect your home from noise, condensation and UV damage with its triple layer defence against the sun and moisture.

The PVCu frame
The PVCu frame is protected against the damaging rays of the sun by being painted every 15 years. The PVC is rot proof and has a double seal design to block water from getting past the glass edges.

The Glass
The glass units are vented to remove the thermal stress and extend the life of the edge seals. There is a range of glass combinations from stsndard 4mm flaot glass through to hardcoat low-e thermal protecion glass

The Vents
The unique patent pending vent system provides a on-going cycle that absorbs and releases moisture to maintain a dry cavity and remove fog and condensation. The special qualities of Bentonite clay inside the vents have a lower moisture release temperature than silicon desiccate found in most other glazing systems. This allows moisture to be released when temperatures are hot and capture moisture when temperatures are cool.

10 Year Guarantee

EVS has provided a 10 Year guarantee encase bad workmanship or the product fails in that time frame.

EVS Draught Stops

EVS Draught Retro Seal
Older timber windows and doors can be upgraded to Healthy Home Standards to prevent draughts by installing EVS Draught Stops. These are made of areated PVC which looks and feel like timber but with the added benefits of being weather proof, and pre-finished as timber or white and can be fitted to most windows and doors as a permanent long term solution.

Join our EVS Sales and Installation Network
  Demand for affordable retro glazing is increasing and EVS is looking to find glazing companies from around New Zealand to provide installation services to our unique range of retro glazing products and services.
Installing EVS is a quick and simple process that allows your business to offer retro glazing services at more competitive prices. EVS will train and support your team with software and product installation.  
Find out More 

Talk to us about your Retro Glazing project. For locations around the rest of New Zealand we can organise local installers for your project

Phone: +64 (0) 274346912
Email: info@evsglazing.nz

EVS Head Office 

EVS Window Technology Ltd
122 Kaituki Ridge Lane
Queensberry Hills
Central Otago 
New Zealand


Email: info@evsglazing.nz
Draught Stop orders Sales@evsdraughtstop.nz

Mobile: +64 (0) 27 4346 912