Treharris · Mid Glamorgan
Aluminium Windows in Treharris
We cover Treharris and wider Mid Glamorgan for aluminium window replacement, from a single kitchen window to whole-house and extension glazing, with survey, supply and fitting arranged.
- CF46
- Guide from £925
Powder coated aluminium windows across Treharris
Aluminium frames are usually finished with polyester powder coating, baked on at the factory in a choice of RAL colours and in matt, satin or textured finishes. Dual-colour frames are possible, such as anthracite grey outside and white inside, so the windows can suit both the street and the room.
Powder-coated aluminium does not need painting, but it does need cleaning. Wash frames with warm water and a mild detergent a few times a year, rinse, and avoid abrasive pads or solvents. Clean more often near the sea or busy roads, where salt and grime sit on the surface for longer.
Aluminium windows are fabricated to order: profiles are cut, coated, assembled and glazed to the survey sizes. Lead times can be longer than for standard white uPVC, particularly for special colours or steel-look designs, and the expected timescale is confirmed in writing when you accept the quote.
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
- Survey, measuring and structural check of each opening
- Thermally broken aluminium frames powder coated to order
- Fitting, sealing and finishing the reveals neatly
- Removal and disposal of the existing windows

Local details for Treharris
- Postcodes covered
- CF46 and the surrounding area, including Nelson (Mid Glamorgan), Gelligaer and Mountain Ash
- Coast
- Treharris is well inland, around 23 km from the nearest coast, so salt exposure is not usually a factor.
- Daylight and sun
- In Treharris the midwinter sun reaches about 15° above the horizon at noon, with roughly 7.6 hours of daylight, rising to about 62° and 16.4 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 Wales
- In Wales, Approved Document N covers safety glazing: safety glass is needed in and around doors and in low-level glazing where people could walk into it.
Guide prices in Treharris
| 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
In Wales, replacing a whole window or glazed external door is building work and is notified either by an installer registered with a competent person scheme or through the local authority's building control. Replacing only the glass in an existing frame is treated as a repair.
Specification choices
Glass upgrades
Triple glazing, laminated acoustic glass, solar-control coatings or obscure glass, chosen per window to suit the room and elevation.
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.
Steel-look windows
Very slim frames with glazing bars that mimic traditional metal windows, adding thermal performance and double glazing to the classic look.
Aluminium Windows in Treharris: questions
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.
What colours can aluminium windows be?
Aluminium windows can be powder coated in almost any RAL colour, in matt, satin, gloss or textured finishes, and many systems offer a different colour on each side. Anthracite grey, black and white are common choices, but heritage greens, creams and bronze tones are available too. Special colours can extend the manufacturing lead time, which is confirmed with the quote.
Do aluminium windows get condensation on the frames?
Modern thermally broken aluminium windows are far less prone to frame condensation than older aluminium windows made without a thermal break. Condensation can still form on any window if a room is humid and poorly ventilated, so trickle vents, extractor fans and sensible heating still matter. Warm-edge spacer bars also help keep the edges of the glass warmer.
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.
Do you cover Treharris for aluminium windows?
Yes. We can quote for aluminium windows across Treharris and the surrounding Mid Glamorgan area, including postcode districts CF46, and nearby Nelson (Mid Glamorgan), Gelligaer and Mountain Ash. 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 Treharris
Free survey for new glazing, clear guide prices and one point of contact for every glazing job.