Castlereagh · County Down
Aluminium Windows in Castlereagh
Want modern, slim-framed windows in Castlereagh? We can quote for thermally broken aluminium casements, tilt and turn and steel-look designs in the colour of your choice.
- BT6
- BT5
- BT7
- Guide from £925
Replacement aluminium windows for homes and businesses in Castlereagh
The price of aluminium windows depends on the size and number of frames, the profile system, opening sashes, colour and finish, glass specification and access. Dual colours, special finishes, glazing bars and triple glazing add cost. See the guide prices for typical ranges, and the written quote fixes your figure.
Modern aluminium window frames contain a thermal break: strips of low-conductivity material, usually polyamide, that separate the inner and outer aluminium. Without it, heat passes straight through the metal. Older aluminium windows made without thermal breaks are a common cause of cold frames and streaming condensation.
Aluminium is strong enough to hold large, heavy glass units in narrow frames, so sightlines are slimmer than uPVC of the same size. That means more glass and more daylight from the same opening, which suits modern extensions, wide picture windows and slim replacements for old steel windows.
Steel-look aluminium windows reproduce the slim frames and glazing bars of traditional metal windows while adding a thermal break and double glazing. They are often chosen to replace failing original steel windows in 1930s houses, though conservation areas and listed buildings may need consent for the change.
What you get
- Written guarantee terms and advice on building regulations sign-off
- Thermally broken aluminium frames powder coated to order
- Removal and disposal of the existing windows
- Fitting, sealing and finishing the reveals neatly

About Castlereagh for this job
- Postcodes covered
- BT6, BT5, BT7 and the surrounding area, including Belfast, Dundonald and Carryduff
- Coast
- Castlereagh is about 5 km from the coast or a tidal estuary, so salt air and wind-driven rain are worth planning for. Salt air attacks metal finishes, so aluminium windows near the coast need a coating and pretreatment suited to marine exposure, stainless or protected hardware, and more frequent washing. Check that the coating terms allow for a coastal site before ordering.
- Daylight and sun
- In Castlereagh the midwinter sun reaches about 12° above the horizon at noon, with roughly 7.0 hours of daylight, rising to about 59° and 17.0 hours in midsummer. Slim aluminium frames let more daylight through the same opening. Large south or west-facing panes can overheat rooms, so solar-control glass may help, while north-facing rooms benefit from high light-transmission low-E glass that keeps heat in during short winter days.
- Access and setting
- Rural homes often mix old stone walls with modern extensions, and aluminium suits both when profiles are chosen carefully. Irregular openings are measured individually, and exposed sites benefit from systems with high weather ratings and well-sealed joints against driving rain.
- Rules in Northern Ireland
- Technical Booklet V covers safety glazing in Northern Ireland, including glass in and around doors and low-level glazing where people could walk into it.
Guide prices in Castlereagh
| Typical job | Guide price inc VAT |
|---|---|
| Casement window, 900 × 1050 mm | £925 – £1,195 |
| Casement window, 1200 × 1200 mm | £1,095 – £1,395 |
| Large window, 1800 × 1500 mm | £1,495 – £1,995 |
| Slimline heritage style, 1200 × 1200 mm | £1,295 – £1,695 |
Get a guide price for your size
Replacement windows on houses in Northern Ireland are often permitted development, but conservation areas and listed buildings can need consent. Check with the council's planning office.
Choosing your aluminium windows
Glass upgrades
Triple glazing, laminated acoustic glass, solar-control coatings or obscure glass, chosen per window to suit the room and elevation.
Tilt and turn
Inward-opening sashes that tilt for secure ventilation or swing open for cleaning and escape, useful for flats and high floors.
Dual-colour powder coat
A different colour inside and out, such as anthracite grey outside with white inside, from a wide range of RAL colours and textures.
Aluminium Windows in Castlereagh: questions
Can aluminium windows replace original steel windows?
Yes, steel-look aluminium windows are designed for this. They copy the slim frames and glazing bars of old metal windows while adding double glazing and a thermal break. Original steel frames are often set into the masonry, so removal can disturb render or plaster, and the survey checks this. Listed buildings and conservation areas may need consent first.
What guarantee do aluminium windows come with?
Manufacturer guarantees apply to the frames, powder coating, hardware and sealed units, and the terms are confirmed in writing. Coating cover often depends on the site environment and on regular cleaning, so read the conditions. Guarantee terms for the installation are set out in writing with your quote, before you agree to go ahead.
How do I look after powder-coated aluminium windows?
Clean powder-coated aluminium windows with warm water and a mild, non-abrasive detergent a few times a year, then rinse and dry. Avoid scouring pads, solvents and pressure washers close to the seals. Keep drainage slots clear and put a little light oil on hinges and locking points. Near the coast, more frequent washing removes salt deposits.
Are aluminium windows better than uPVC?
Neither is better for every home; they suit different priorities. Aluminium gives slimmer frames, larger glass areas, a hard-wearing powder-coated finish and a wide colour choice. uPVC usually costs less and has chunkier frames. Both can meet the energy standard for replacement windows when specified correctly, so compare the certified ratings, the look you want and the guide prices.
Do you cover Castlereagh for aluminium windows?
Yes. We can quote for aluminium windows across Castlereagh and the surrounding County Down area, including postcode districts BT6, BT5 and BT7, and nearby Belfast, Dundonald and Carryduff. Start with your postcode on the quote form and a glazier will arrange a free survey before giving you a written quote.
Get a written quote in Castlereagh
Free survey for new glazing, clear guide prices and one point of contact for every glazing job.