Finding new windows that balance visual appeal and performance can be challenging. However, Origin manufactures two window systems that offer high thermal performance and security as well as a sleek design. The Premium OW80 Window features an industry-unique internal and external flush casement finish for a clean finish. Meanwhile, the Slimline OW70 offers an external flush casement design, but comes with the added benefits of having sightlines as slim as 65mm, offering an ultra-modern aesthetic.
Click on one of the sections below to learn more:
What are slimline windows?
There are no definitions for what can be classified as a slimline window – it’s essentially the sightline width of a window, and this will vary depending on material, brand and system chosen. Certain materials like uPVC tend to be less strong than aluminium or steel, so they often have wider sightlines to ensure structural integrity.
Aluminium is a practical choice when you want to minimise the amount of profile in view because it has a very good strength to weight ratio, meaning it can be slim but will be secure and be able to be made in vast sizes.
Windows with minimal profile can look exceptionally modern and elegant. They are able to maximise natural light and views of the outdoors without compromising on style, security or performance.
The pros and cons of slim windows
Windows with minimal profile offer more expansive glazing, and this enhances natural light and views of the outdoors.
Benefits of slim windows
- More glass area for natural light to flood into the home.
- Wider glass panels emphasise your outdoor views.
- The slimline Gallery Windows offer the most uninterrupted and contemporary look.
- Adding heritage-style glazing bars causes minimal obstruction.
Possible drawbacks to consider:
- While it depends on the thermal conductivity of the window materials and glass specification, larger glass areas can be less energy efficient.
- Ultra-thin frames may be less durable than wider profiles.
Do slim windows suit modern and period properties?
The advantage of modern materials is that they can be manufactured to suit various design and functional preferences, whether that’s a contemporary new-build or a traditional renovation.
Windows can feature uninterrupted glazing or can have bars to create a Georgian-style grid effect. The delicate symmetry is one of the reasons Georgian-style windows are popular to this day. Slimline profiles help you achieve a more authentic and heritage look. They also allow you to enjoy the practicality of modern materials without compromising on style.
Explore modern Georgian window case studies
Can I have slimline Georgian windows?
Georgian windows have more profile in view because of the traditional grids that go across the glass, so it’s important to find a window system with slimmer sightlines to counterbalance this. The OW70 Slimline offers sightlines as slim as 65mm, so offers a perfectly graceful aesthetic even when astragal bars (grids that are stuck onto the outside of the glass) are chosen.
"We are thrilled with the outcome of the project. It’s everything we could have dreamed of and more."
- Oxfordshire homeowners
What is a flush casement window?
To understand flush casements, you need to first understand casement window anatomy. The overall window frame is fitted into the opening, and the casement is the moving component that sits within the outer frame. The casement often projects slightly outwards when the windows are closed. However, with flush casements, the frame and casement align perfectly for a more seamless finish.
What are the benefits of flush windows?
The difference between flush and standard windows is largely aesthetic, but there are some practical advantages:
- Appearance: instead of a lipped or overlapping casement, there is just a sleek shadow where the casement sits within the frame.
- Maintenance: the uniform surface may be less likely to accumulate dirt and can be easier to clean.
- Security: The flush design may be harder to jemmy open from the outside.
Should you have flush casement on the inside or the outside?
Some designs have a flush casement on both the inside and the outside (Origin’s OW80 Window), some have it just externally (the OW70), while others have no flush frames. Having the flush casement on the outside creates a clean aesthetic and may add an extra layer of security. A flush internal casement is purely for aesthetic appeal, but it may also provide some maintenance advantages.
The OW80 Window from Origin has flush internal and external casement for a premium finish. Whereas, the slimline OW70 Window has a thinner frame but only features an externally flush casement.
Practical considerations for slimline flush windows
Here, we compare our two window systems in the table below to help you decide between the Slimline OW70 or the Premium OW80.
| Factor | Slimline OW70 | Premium OW80 |
|---|---|---|
Energy efficiency | Excellent: U-Value from 1.2 | Exceptional: U-Value from 0.8 |
Security | High level of security: features externally flush casement, multipoint locks, crimped frames and hinge guards. | High level of security: features externally flush casement, multipoint locks, crimped frames and hinge guards. |
Maximum fixed frame size | 4.8m2 | 7m2 |
Available window types | Bay, Casement or Picture Window | Bay, Casement, Gable, French, Tilt and Turn or Picture Window |
Frequently Asked Questions:
Are slim flush windows more expensive?
The casement sitting flush with the outer frame requires a good level of engineering and design, which is why this aesthetic is only usually available on premium window systems.
Can I have thin profiles for tilt and turn windows?
This style of window can be harder to design with a slimline profile because of the more complex opening mechanisms with its dual operation. Origin’s tilt and turn windows are available on the OW80 system which has an 80mm frame depth.
Can you get slim and flush PVC windows?
uPVC is a practical window material, but it is not as strong as some other materials, so it can be harder to achieve slim sightlines. Flush PVC casements are also possible, but the premium finish is not standard for entry-level windows.