There are almost as many styles of windows as there are stars in the sky! Well, OK that’s a slight exaggeration, but with variations such as how they open, some with fixed panes, different materials, different shapes, bay windows, wall windows, single, double and triple glazed, Low E coatings, Passive House compliant you can quickly see that they add up. There is also the look which is a completely personal choice.
Some most common opening styles on the market are listed below. Let’s look at them from the functional, practical and thermally efficient point of view.
1. Casement
Casement windows are widely used and are very common windows. The windows are hinged to frame along the long side of the window. Rebates are provided in the frame to receive the windows. Often a mesh is attached as a flyscreen, these can be the cheapest fibreglass mesh or the expensive stainless steel ‘CrimSafe’ style screens for added security.
Casement windows can be fitted with a compression seal to ensure an airtight seal. They are one of the most practical, cost effective and highest performing window opening style.
Airtightness: ★★★★★
Affordability: ★★★★★
2. Tilt & Turn
Tilt & turn windows offer dual functionality. The first option is to turn the handle 90 degrees to swing the window sash open, the second option is to turn the handle 180 degrees to tilt the sash in to vent from the top. This allows for ventilation and security simultaneously.
Tilt & turn windows are a popular choice for egress windows as they are large enough to allow a person access in and out. Larger tilt & turn windows can be used to allow access to an exterior space like a roof or balcony. Tilt and turn windows are an ideal compromise, being able to open two different ways, they can be fitted with a compression gasket to ensure an airtight seal.
Tilt & Turn combines style, functionality and performance all in one. It’s our favourite style that we recommend to our clients because it’s practical, airtight and elegant.
Airtightness: ★★★★★
Affordability: ★★★★☆
3. Awning
An awning window is a single pane that is hinged at the top of the frame creating an awning effect. An awning window is essentially a casement window turned sideways. However, awning windows are typically smaller and can be installed higher on a wall to add architectural interest and provide ventilation and light without sacrificing privacy or security.
They are good for ventilation when it’s raining because the pane keeps the water out. Awning windows are typically opened by winding a chain mechanism in and out. They are usually restricted to open 125mm based on National Construction Codes as a first floor safety feature to stop young children from falling out of the window.
Awning windows can be fitted with a compression seal to ensure an airtight seal. Like Tilt & Turn, ML awning windows can also open in two different ways. They use handles that click to lock from inside instead of winders. No key is required from the inside and are totally secure from the outside. They are practical, easy to operate and airtight.
Airtightness: ★★★★★
Affordability: ★★★★☆
4. Sliding
Sliding windows and doors glide open horizontally from one side to the other. Sliding on a track, they require no extra space to operate making them a popular choice for patios, porches, tight walkways or anywhere you wouldn’t want an outward swinging door or window. Sliding windows offer easy and controlled access to fresh air and provide good energy efficiency when closed.
Sliding doors are incredibly popular in modern-style homes. They feature clean lines and sleek designs. They can feature large panels of unobstructed glass to fit spacious horizontal areas on a wall. Sliding windows tend to be on the cheaper end of the cost spectrum. The quality of sliding doors can vary substantially in the market.
A regular sliding door uses a static rail or sill fixed at the bottom of the outer frame. The door is supported by small rollers which move along the bottom rail. To maintain sufficient water and air tightness, sliding doors have very little clearance between the rail and the door, creating significant friction and rubbing of the seals, even on brand new doors. Over time, as debris and corrosion may further reduce the clearance, the wheels or rollers the door sits on tend to wear out, sliding doors become harder and harder to open, especially on larger doors. You may probably notice it yourself on older slider doors. Our sliding doors come with stainless steel rollers instead of Nylon wheels, which are more durable.
Airtightness: ★★★☆☆
Affordability: ★★★★☆
5. Lift and slide
Lift and slide is the least common out of the 5 opening styles but is also one of the most practical, functional and thermal efficient style of sliding doors. Lift and slide doors utilise a mechanism that lifts up the door from its airtight seal before sliding. It can be used with nearly limitless sliding door designs, from conventional two panel setups, to multi-panel, corner-less configurations spanning the width of a house or building.
As you turn the handle down, the door is lifted by a mechanical system. The door is fully released from its seals and has more clearance from the bottom rail. The door can now slide at the push of a finger. Move the handle back in the original position and the door is lowered back down on the bottom of the frame for maximum air and water tightness. In the closed position, the rail is completely protected from debris and corrosion.
Lift and slide have three main advantages:
· Ease of use, often being able to be pushed open by a small child.
· Better water and air tightness, reduced wear and tear
· Improved forced entry resistance
Lift and slide is a very popular style for our energy conscious clients. They can be sealed when closed and offer increased airtightness compared to normal sliding door. However, the mechanism is more complex than sliding doors so they do attract higher cost.
Airtightness: ★★★★☆
Affordability: ★★★☆☆
Other opening types (e.g., sash or louvre) :
Sash windows consist of pair of moveable windows attached to one frame. The windows are arranged one above the other. These two windows slide vertically with in the frame. So, its possible to open the windows on top or at bottom at the same time.
Older houses used Sash windows extensively, usually made with a timber frame with lead or iron counterweights. As you can imagine double hung windows can be very heavy and require a lot of maintenance.
Either sash or louvre windows can be airtight as there is usually an air gap between the glass panels that may cause drafts.
People tend to choose sash and louvre windows for the look when renovating older homes. The two opening styles are not high performing from a thermal efficiency perspective. The aluminium frames can’t be thermally broken for sash windows. Typical louvre is single-glazed. ML has chosen to focus on high performing windows only and so we’ve decided not to supply sash windows any more.
Other key components to look out are:
- Wheels – Are they Nylon or Stainless steel?
- Handles and locks – They are the parts that you touch every time when you open or close the doors. It’s worth considering better quality handles, if you have a choice.
- Finish – Can you see air gap. Can you feel the draught? Do they have brush seals?
* Note: airtightness and affordability rates are based on ML window styles.
Contact us via m@mlwindows.com.au or learn more about ML Windows at https://www.mlwindows.com.au