Flush casement vs stormproof windows: Weather seals, sightlines and cost
- 3 December 2025
- News
Flush casement vs stormproof windows: weather seals, sightlines and cost
Choosing new windows is a big decision, especially when you’re torn between two popular styles. The question of flush casement vs stormproof windows (now more typically referred to as standard casement windows) is one we hear from homeowners on a regular basis.
Both types of window design are reliable, stylish and known for strong weather performance, but they each bring something slightly different to your home.
Flush casements offer a cleaner, more modern look inspired by classic timber windows, while stormproof casement windows provide extra protection in exposed areas and are usually the more affordable option.
Both deliver great energy efficiency too, helping to keep your energy bills in check. Your ideal choice depends on your type of property, personal preferences and how close you live to harsh weather conditions.
Introducing flush casement windows
Flush casement windows are loved for their timeless aesthetic qualities. When the sash closes, it sits level with the face of the window frame, creating neat flush fit windows with slim, tidy sightlines. They open in the same way as other types of casement window, but the flush design gives them their distinctive traditional appearance.
Over the past ten years they’ve become a popular choice for both period properties and modern extensions, especially in conservation areas where a sympathetic timber-style appearance is preferred. Homeowners like them because they provide the charm of older timber windows without the upkeep, while still giving the security features, double glazing and weather performance expected from today’s materials.
Introducing stormproof windows
Stormproof casement windows are the classic style most people picture when they think of new windows. The sash slightly overlaps the frame (a “lipped” design) which adds extra protection against heavy rain and wind. This style of window opens outwards from the side or top and remains the most popular choice in the UK thanks to its versatility, wide range of colours and competitive pricing. Truth be told, it’s highly unlikely that you’ll walk down any street in the country without seeing one.
They suit different architectural styles, from new builds to rural family homes, and are known for strong home security thanks to modern multi-point locks. For many homeowners, they’re the type of window that simply works everywhere.
What are the differences between flush casement and stormproof windows?
Here’s a simple overview of the main difference between the two styles:
| Factor | Flush casement windows | Stormproof casement windows |
| Appearance | Flat, clean exterior for a traditional style | Lipped sash gives a more defined profile |
| Natural light | Slimmer sightlines for generous light | Wide openings, similar levels of light |
| Weather performance | Excellent with quality seals | Extra protection in extreme weather |
| Thermal efficiency | Strong performance with modern glazing | Equally strong with double glazing |
| Typical costs | Often slightly higher | Often the more budget-friendly option |
Appearance
- Flush design: flush sash windows offer a smooth, understated look suited to period properties and conservation areas.
- Stormproof design: lipped casement windows create a more familiar shape that suits most homes.
Natural light
- Flush windows: slim profiles maximise the glass area.
- Stormproof windows: offer wide, clear openings for bright, airy rooms.
Weather performance
- Flush windows: advanced seals and modern materials give dependable protection.
- Stormproof windows: ideal for exposed or coastal locations where extreme weather conditions are common.
Thermal efficiency
- Both styles: with double glazing and modern uPVC or aluminium frames, either option can improve the energy efficiency of your home and help reduce heat loss.
Typical costs
- Flush design: often priced a little higher due to the specialised window frame styling.
- Stormproof windows: usually the more affordable option, though both offer long-term value and peace of mind.
Flush casement windows from Crown
At Crown Conservatories, Windows and Doors Ltd we supply flush casement window options in both uPVC and aluminium materials, all made to measure and crafted to high quality standards using state-of-the-art machinery. They combine traditional style with modern performance, offering strong home security, A rated energy efficiency and a wide range of colours and glass designs.
Colours and glazing options
You can choose from dozens of colours, including whites, greys, greens, blues and realistic woodgrain foils that give the appearance of timber windows without the upkeep.
Glazing options include Autumn, Stippolyte, Chantilly, charcoal, Cotswold and many more, helping you tailor privacy and aesthetic appeal to your next project.
Stormproof (casement windows) from Crown
Our stormproof casement windows provide strong weather resistance, modern security features and a classic style of window suited to almost any type of property. They are available in both uPVC and aluminium, with double glazing as standard and a wide range of colours such as anthracite grey, cream, black, white and dark green.
Colours and glazing options
We offer glass patterns including Flemish, laurel, taffeta, digital, florielle and contour, giving you plenty of choice for personal preferences and privacy levels.
FAQs
What is the main difference between flush casement and stormproof windows?
Flush casement windows sit level with the frame for a tidy finish, while stormproof casement windows have a lipped sash that offers extra protection against harsh weather conditions. Both types are strong performers and suit different architectural styles.
Are flush casement windows suitable for conservation areas?
Yes, the traditional appearance makes them a good match for properties that need timber-style character.
Which style offers better security?
Both styles come with advanced locks, strong frames and tough double glazing for dependable home security.
Who are Crown?
We are Crown Conservatories, Windows and Doors Ltd, a trusted installer with over 20 years of experience in Milton Keynes and the surrounding areas across Buckinghamshire and Northamptonshire. We fit made to measure windows, doors and conservatories using premium suppliers including Rapid, Smart Aluminium, Formula One Range, Apeer, Eco-Slide and Guardian Roof Systems.
Our fitters are FENSA registered, and every installation comes with a 10-year warranty and an insurance-backed guarantee. You can also visit our state of the art showroom in Milton Keynes or request free 3D design plans to help you picture your project.
If you’d like advice on the right type of window for your home, call us on 01908 507 778 or email info@crownwindows.co.uk.
Key findings
- Flush casement windows offer a tidy, traditional look inspired by timber.
- Stormproof casement windows are versatile and budget-friendly.
- Both styles provide strong weather performance and energy efficiency.
- The right choice depends on your type of property and location.
- Crown offers both styles made to measure with a wide range of colours and glazing options.
