Gwynedd & Anglesey · Wales

Secondary Glazing in Gwynedd & Anglesey

Single-glazed sash windows in Gwynedd & Anglesey can stay as they are, with vertical sliding secondary glazing fitted inside to reduce draughts and cold.

Guide from £465
5 towns covered
Postcode areas LL

Gwynedd & Anglesey: internal secondary windows

The price of secondary glazing depends on the size and number of windows, the opening style, the glass specification, any shaped or arched heads, reveal depth and condition, and access. Acoustic laminated glass and shaped frames cost more than standard clear glass in rectangular frames.

Opening styles include vertical sliders that line up with sash window meeting rails, horizontal sliders for wide openings, hinged casements, lift-out panels for windows that are rarely opened, and fixed panes. The choice depends on how you use the window, cleaning access and fire escape needs.

Secondary glazing leaves the original window untouched and fits a second, independent window inside it. The air gap between the two works with the glass to reduce noise and heat loss. In most cases the installation can be taken out later without damaging the historic window or reveal.

Slim aluminium frames are designed to sit within the window reveal and line up with the original glazing bars or meeting rails. Matching sightlines keeps the secondary unit discreet from outside and inside, which matters for period homes and conservation areas.

Sash window with secondary glazing in a period sitting room

Towns we cover for secondary glazing in Gwynedd & Anglesey

Choose your town for local details, nearby areas and the postcode districts we cover.

What applies in Gwynedd & Anglesey

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.

Where a window is an escape route, its replacement in Wales should give at least the same escape opening as before.

Gwynedd & Anglesey has its own coastline, so for homes and businesses near the sea, salt air and wind-driven rain are part of the brief. Coastal properties often have older windows exposed to wind-driven rain and draughts. Secondary glazing adds a sealed inner layer that reduces draughts and cold, while the original window keeps out the weather and its condition is protected from inside.

Rural cottages and period homes often have single-glazed timber windows that cannot easily be replaced. Secondary glazing reduces draughts and heat loss in exposed locations, and the surveyor allows for uneven reveals and older plaster when fixing frames.

Guide prices

Guide prices inc VAT for typical jobs. Remote and island locations are quoted by arrangement. Your written quote fixes the price after measuring.
Typical job	Guide price inc VAT
Slider, 900 × 1200 mm	£465 – £595
Slider, 1200 × 1600 mm	£665 – £845
Acoustic glass, 1000 × 1400 mm	£675 – £865

Choosing your secondary glazing

Low-E glass

Coated glass that reflects heat back into the room, improving insulation when the original window is single glazed.

Vertical sliding

Panels slide up and down, with meeting rails aligned to sash windows so the secondary unit is discreet from inside and outside.

Lift-out panel

A lightweight panel that lifts out of its frame, for windows rarely opened, giving a slim and economical secondary unit.

Fixed panel

A non-opening unit for windows never opened, giving the most airtight seal for noise and draught reduction.

Secondary Glazing in Gwynedd & Anglesey: questions

Which opening style should I choose?

Choose based on how you use the window. Vertical sliders suit sash windows and keep meeting rails aligned. Horizontal sliders suit wide windows. Hinged panels give full access for cleaning and escape. Lift-out and fixed panels suit windows that are rarely or never opened, and give the tightest seal for noise.

Is secondary glazing as good as double glazing?

It depends on the goal. For noise, secondary glazing is often more effective, because the wider gap between the two windows reduces sound better than the narrow cavity of a sealed unit. For heat, a well-sealed secondary unit with low-E glass significantly improves a single-glazed window. It also keeps original windows, which matters in listed buildings.

How do I clean and look after secondary glazing?

Open or remove the panels as designed, then clean the glass with mild soapy water and a soft cloth. Wipe the aluminium frames and runners, and keep tracks free of dust so panels slide smoothly. Check seals and catches occasionally. Avoid abrasive cleaners, which can scratch coated glass.

How much noise does secondary glazing block?

Results depend on the size of the gap between the windows, the glass type and thickness, the seals and the original window. A larger cavity and acoustic laminated glass give the strongest improvement. The survey checks reveal depth and noise sources, so the specification can be tailored to the noise you are dealing with.

Which parts of Gwynedd & Anglesey do you cover for secondary glazing?

We cover the whole of Gwynedd & Anglesey, including Bangor (Gwynedd), Holyhead, Caernarfon, Pwllheli and Dolgellau, and postcode areas LL. Building rules for secondary glazing here follow the regulations for Wales. Enter your postcode on the quote form and we will confirm cover; then a glazier will arrange a free survey before giving you a written quote.

Other glazing services in Gwynedd & Anglesey

All glazing in Gwynedd & Anglesey · Secondary Glazing across the UK

Get a written quote in Gwynedd & Anglesey

Free survey for new glazing, clear guide prices and one point of contact for every glazing job.

Get a guide price 0800 088 6248 WhatsApp