Double Glazing Windows Anerley

Soaring heating bills and cold spots around old frames often mean your glazing is no longer doing its job. We replace tired sash, casement, bay and bow windows with made-to-measure double glazing, fitted by FENSA-registered installers, with a free home survey and a 10-year guarantee for peace of mind.

Every unit is specified to millimetre tolerances, using A-rated 24–28mm argon-filled low‑E glass, warm-edge spacers and Q‑LON gaskets to cut draughts and condensation in your Sheffield home. Frames are internally beaded, multi-point locked and set up for traditional cords or modern balances, with hardware, drainage falls and sightlines agreed from clear CAD templates.

You’ll receive signed final sizes, section drawings and test-rated acoustic and security performance, plus FENSA certification on completion. Read on to compare costs, lead times and guarantees so you can plan your new windows with confidence.

Takeaways

• A‑rated double glazing cuts heat loss dramatically versus single panes, lowering heating bills and improving year‑round comfort.
• Multi‑point locking and laminated glass increase security, helping deter forced entry and reduce street noise.
• FENSA or CERTASS registration and transferable guarantees protect your investment and support future resale value.
• Precise site survey, CAD sign‑off and made‑to‑measure manufacture minimise fitting issues and disruption on installation day.
• Flexible monthly finance and access to current UK energy‑efficiency schemes spread upfront costs and improve affordability.

Is Made-to-Measure Double Glazing Right for Your Home?

Made-to-measure double glazing is worth considering if your openings are out of square, you’re in a conservation area, or you need specific thermal or acoustic performance.

On survey, we check every frame for rot, twist and sash geometry, then record the as-built sizes to the millimetre where existing profiles need to be matched for heritage work. We measure reveal depth, check for irregular brickwork, and confirm clearances for trickle vents and draught seals so the new units sit properly without packing out with timber wedges.

For performance, we’ll agree targets up front – for example:

• A-rated 28mm argon-filled sealed units with low‑E glass to bring U-values down to the level your EPC or building control require.
• Acoustic laminated glass and warm-edge spacers sized to hit the Rw rating needed for traffic or flight noise.

On traditional windows we check how new sashes will work with your existing ironmongery, or specify new hardware and multi-point locking that suits the frame and keeps everything internally beaded for security. We use Q-LON or equivalent compression gaskets in the design so the window actually seals when it’s shut, not just on paper.

Before anything is ordered, you get clear section drawings and glass specifications you can pass to planning or the conservation officer if needed. The contract sets out accepted tolerances on frame size, glass sightlines and operation, plus how we’ll check it on site – from spirit-level checks on frames to confirming trickle vent sizes and recording the FENSA certificate number on completion.

Energy and Comfort Benefits of Double Glazing

Comfort isn’t guesswork. A well-specified 28mm A-rated sealed unit with low-E glass, argon fill and a warm-edge spacer can cut conductive, convective and radiative heat loss enough to hit the U-values needed for your EPC and building control. That gives you steadier room temperatures, fewer cold spots near the glass and less chance of waking up to condensation on the inside pane.

We match glass coatings and gas fills to what you actually need, not just what’s cheapest on the day. Low-E coatings are placed to keep more heat in during winter while still managing solar gain, and argon-filled units are sized to the right cavity width so the centre-of-glass U-value ties in with the whole-window figure.

Edge performance is just as important as the glass centre. We use warm-edge spacers and tested sealants with proven gas retention, so the unit keeps its declared Uc for its design life instead of fogging up after a few years. Correct packing, squaring and sealing on install stop thermal bridging and draughts around the frame, which is where a lot of cheaper installs lose you comfort.

Key points we specify on every job:

• Low-E coating type and position to balance heat retention and solar gain
• Argon-filled 28mm sealed units matched to the frame for the target U-value
• Warm-edge spacer bars and durable edge seals to keep gas in and condensation out
• Tight installation tolerances, full perimeter sealing and Q-LON gaskets to cut draughts

All installations are signed off with a FENSA certificate and registration number, so your U-values and compliance are properly recorded for future EPC checks in your area.

What to Compare: Thermal, Sound and Security

Thermal performance usually gets most of the attention, but we always weigh up three things side by side: heat loss, noise and security. Changing the glass build-up or frame spec to help one will affect the others, so it all has to be planned as a full window system, not just a pane of glass.

On the thermal side, we’re looking at the centre-pane U-value of the A-rated, argon-filled double glazed unit, the type of warm-edge spacer, and how the frame and fixings are detailed so you don’t get cold bridging. A typical made-to-measure uPVC window with a 28mm sealed unit, low‑E coating and Q‑LON gaskets will easily meet current Building Regulations and cut draughts right back.

For sound, we’ll specify an RW / dB rating that matches the noise outside your property, not just a vague “soundproof” claim. Laminated glass, different glass thicknesses and uneven cavity depths between panes all help knock down low‑frequency traffic noise better than a basic 4‑16‑4 unit.

Security is about more than just “toughened glass”. We use multi-point locking, reinforced hinges, internally beaded frames and laminated glass where needed, so the unit meets recognised impact and tool-resistance standards. Installed as a full system, that gives a far more secure window than a single upgrade on its own.

There are trade-offs: for example, laminated units are heavier, which can nudge the U-value and hardware choice. We check the manufacturer’s system data, size limits and glass weights before we price anything, and on completion you get a FENSA certificate with the registration number showing the install meets thermal and safety requirements as fitted on site.

Double‑Glazed Sash Windows: Pros, Cons, Best Uses

If you like the look of traditional vertical sliders but need modern performance, double‑glazed sash windows are the way to do it without upsetting the sightlines too much. We use A‑rated, argon‑filled low‑E sealed units sized to suit either traditional weights and cords or modern spring balances, so you still get a smooth action with the extra glass weight.

Typical replacement sashes use 24–28mm sealed units with warm‑edge spacers to bring U‑values down to current Part L requirements and improve RW sound reduction at the same time. Meeting rails and stiles are reinforced so they can carry the extra load, and we match the original bar layout so the overall look from the street stays close to what was there before.

You do need to allow for heavier sashes and a slightly chunkier profile, so we check the frame, weight pockets and pulley gear before pricing any job in, for example, older terraced properties in Manchester. We’ll also go through trickle vent options and night‑vent positions so you don’t end up with condensation or draught issues after the old single glazing comes out.

Key points we size and specify on every sash job:

• Sash weight and counterbalance capacity (kg, stroke and spring or cord friction)
• IGU thickness, gas fill and spacer type vs your U‑value target
• Reinforced meeting rails, locks and keeps to suit PAS24‑style security and multi‑point gear where needed
• Access for cleaning and maintenance, including expected seal life and hinge/cord service intervals, with a FENSA certificate number issued on completion

Double‑Glazed Casement Windows: Performance and Styles

Casement windows hinge from the side and open out, but the performance is all in the detail. You get the quoted U-values only if the frame is stiff, the hinges are specified correctly and the perimeter seal is continuous. We use thermally broken aluminium or steel-reinforced uPVC, A-rated 28mm argon-filled units with a soft-coat low-E inner pane as standard on our double-glazed casements.

Good security and draught-proofing comes from proper compression on the seals. Multi-point locking keeps the sash pulled evenly onto the Q-LON gaskets, so you don’t get cold spots round the corners over time. All units are internally beaded, so the glass can’t be removed from outside, and every job is signed off with a FENSA certificate number on completion.

For noise control, we specify laminated acoustic glass with different pane thicknesses and staggered cavities, not just “thick glass”. We quote the lab-tested Rw and Rw+Ctr ratings on the order, so you know exactly what sound reduction you’re paying for, rather than a vague “soundproof” claim.

Flush casement frames give a cleaner sightline and shed water better if the clearances are set right. We keep frame-to-sash tolerance at 2mm or less and build in drainage channels with at least a 5° fall, so water clears and doesn’t sit in the frame. Hinge backset, handle torque ratings and service intervals are all written into the project schedule, which makes future adjustment and maintenance straightforward for any glazier in and around Manchester.

Bay & Bow Double Glazing: Style, Light and Space Benefits

Bay and bow double glazing does more than alter the appearance of a façade. By projecting the window line, these configurations increase glazed surface area, draw in additional daylight and can subtly influence solar gain. They also reshape the internal footprint, creating extra usable floor space and a greater sense of volume. The following sections explore how design choices, projection angles, structural considerations and performance data work together to define the light, space and comfort benefits of these window forms.

Enhanced Natural Light

Bay and bow windows will pull more daylight into a room, but only if they’re set out properly. We look at projection depth, sash angle, glass size and frame sightlines on every job, not just what fits the hole.

A deeper projection increases the sky view and gives you more useful daylight in the middle of the room. We’ll set the angle of the sashes so the A-rated, 28mm argon-filled, low‑E units are picking up light without creating glare across worktops or TV screens.

Glazing area and mullion spacing are worked out so you’re not losing light to chunky profiles. Slim uPVC or aluminium frames, internally beaded with Q‑LON gaskets, keep the aperture large while still giving you a secure, multi‑point locking frame.

On site we also check:

• Orientation of the wall (south, east, etc.)
• Reveal depth and any overhangs
• Required U-value and visible light transmittance (VT)

That lets us balance natural light, glare control and thermal performance, so you get a bright room, low draughts and a FENSA certificate number on completion.

Expanded Living Space

A bay or bow window is a simple way to gain a bit more usable space without touching the brickwork too much. By pushing the frame line out and using made-to-measure uPVC or aluminium frames, you typically pick up around 0.5–1.5 m² of extra floor area for seating, storage or just easier circulation.

We use A-rated, 28mm argon-filled sealed units with low-E glass as standard, so you get the extra glass area without sacrificing thermal performance. Frames are internally beaded with multi-point locking and Q-LON gaskets to keep security tight and draughts down. All angles and mullion positions are set on site to suit your sightlines, so you’re not staring at a post when you sit down.

A well-designed bay also improves natural light levels and reduces the need for artificial lighting during the day. By setting the bay angle around 30–45° and keeping cill heights consistent with the rest of the room, you get better views out and a stronger visual connection to the garden or street, without excessive solar gain.

Typical figures we work to:

All work is signed off with a FENSA certificate on completion, with the certificate number provided for your records.

Typical Costs and Lead Times for Made‑to‑Measure Windows

Made‑to‑measure double‑glazed units are usually priced per window, with costs varying by frame material, glazing specification and size. Mid‑range uPVC options often start in the low hundreds of pounds, while bespoke timber or aluminium systems can run into the thousands. Lead times are typically quoted in calendar weeks, from around 4–8 weeks for straightforward orders to longer for specialist glass or finishes. Alongside the unit price, separate allowances are normally made for removal, access, installation and final sign‑off, which we explore in more detail next.

Typical Price Ranges

Made-to-measure double glazing isn’t off the shelf, so cost and lead time depend on the exact spec – frame material, glass type, A-rated 28mm sealed units, argon fill, low‑E coating, and how awkward the install is. Extra ironmongery, trickle vents, toughened or laminated panes, and access issues (scaffolding, restricted openings) all push the price up and can add a week or two.

As a guide, for standard domestic work in the UK you’re usually in these brackets:

• Basic single casement, double-glazed (uPVC, A-rated 28mm unit, internal beading, standard multi-point locking): £150–£350 per unit
• Thermally enhanced sash or bay (uPVC or thermally broken aluminium, low‑E, argon-filled, warm-edge spacer, trickle vents): £400–£900 per unit
• High acoustic / laminated units (special acoustic laminate, wider cavity, upgraded seals and Q‑LON gaskets, reinforced hinges): £800–£1,500+ per unit
• Made-to-measure heritage / multi-pane (slimline units for existing openings, astragal bars, colour-matched finishes, specialist ironmongery): £1,200–£3,000+ per unit

If you need extra acoustic insulation, solar control, or obscure glass in bathrooms and stairwells, build that into your budget from the start. Keeping frames cleaned down, drainage slots clear, and gaskets lightly lubricated helps the Q‑LON seals last longer, protects the finish, and cuts down on future repair costs.

On completion you should always get a FENSA certificate with the installation address and certificate number, plus the paperwork for any sealed unit guarantees and hardware warranties.

Production And Lead Times

Production & Lead Times

Costs and specification choices directly affect how long your made‑to‑measure windows take to build, so plan timings at quote stage, not after you’ve signed off. Your lead time will depend on the frame material, 28mm argon‑filled A‑rated units, hardware, and any extra machining for trickle vents or astragal bars.

Standard uPVC or aluminium casements and sash windows are usually on a 4–8 week fabrication slot from final survey sign‑off. Larger bay and bow assemblies can run longer as the frames are built in sections, dry‑fitted, then re‑set to keep the sightlines tight and the sills level.

Allow extra time if you want specific materials:

• Stained or hardwood timber sections can add 1–3 weeks for grading and treatment.
• Non‑stock aluminium colours or foiled uPVC might add a week while profiles are brought in.
• Special glass (toughened throughout, laminated, acoustic or low‑iron with low‑E coating) can add 1–2 weeks at the glass plant.

We also allow for possible delays from supplier shortages, failed glass units, or transport issues, and we’ll flag that early rather than the week before fitting. On every job in Manchester and beyond we work to a simple, written schedule with key milestones: profiles on order, frames in fabrication, glazing complete, and installation booked, tied to your FENSA certificate issue on completion.

Installation And Additional Costs

Final price and timing for made‑to‑measure double glazing depend on access, structural condition, and the spec you choose, so we set this out clearly before any order goes in. Lead times are normally 2–8 weeks for standard A‑rated, 28mm argon‑filled units with low‑E coating, longer if we’re dealing with large bays or tricky access in older properties around the area.

We itemise every job so you can see exactly what you’re paying for:

• Supply of frames and A‑rated 28mm sealed units (internally beaded, multi‑point locking, Q‑LON gasket as standard)
• Fitting and finishing, including mastic seal, trims, and making good
• Scaffolding or access towers where needed
• Any structural work to openings and any council permits

Labour is priced on clear day rates and estimated man‑hours, with travel included if you’re outside our usual patch. Ancillary materials are listed separately, covering fixings, sealants, trims, protective films, and waste handling.

Old frames and glass are removed and disposed of correctly, with any hazardous waste (like old putty with lead paint or wired glass) shown as its own line item. If you want, we can add an aftercare plan that sets out:

• Warranty period on frames, hardware, and sealed units
• Planned service visits for hinge and lock adjustment
• Post‑installation draught and seal checks

All jobs are backed up with written specifications, agreed acceptance standards (sightlines, seal finish, operation of sashes), and staged payments tied to clear milestones. You’ll receive your FENSA certificate number on completion once the install is signed off.

How to Measure, Specify and Order Custom Windows

We start by fixing clear reference points on each opening and use the same measuring method all the way round the job. That means every made-to-measure frame lines up with the original brickwork or render, and your FENSA certificate details match what’s actually been fitted.

Each window is measured for width and height in three places, then checked corner-to-corner so we can see if the opening is out of square and allow for packers. We record frame tolerances in millimetres, set the maximum sash alignment deviation, and note any twists or bows that could affect how an A-rated, argon-filled 28mm unit sits in the frame.

Depth to finished plaster, reveal offsets and any pipes, tiles or trims that might foul the new frame are all written up on the job sheet. Where needed, we sketch each opening or use simple CAD templates, marking hinge side, handle side, trickle vents, cill projections and multi-point lock positions.

Those measurements are turned into a full window schedule for the factory:

• Frame profile and colour, including internally beaded sashes
• Glass spec (A-rated, 28mm sealed unit, low-E coating, argon-filled)
• Hardware layout, handle height and lock keeps
• Q-LON gasket positions and drainage slots
• Tolerance bands and machining sizes for drainage and fixing points

Drawings or scaled sketches go in with the purchase order so the glazier can double-check before cutting. Final sizes and details are signed and dated before release to production, so what turns up on site is ready to fit without on-the-day alterations.

Choosing a Supplier and Installer: Questions to Ask

Choosing a glazing supplier and installer is as much about paperwork and accountability as it is about the products themselves. It’s important to check who will actually fit your windows, what formal qualifications they hold, and how their work is backed up in writing. You’ll also want clarity on warranties, what they cover, how long they last, and how to make a claim. The following sections break these points down so you know exactly what to ask and expect.

Installer Credentials

Installer checks that actually protect your warranty

Price and lead time matter, but the installer’s paperwork is what keeps your A-rated, 28mm argon-filled units and multi-point locks covered if anything goes wrong. Manufacturers and insurers will look at who fitted the windows before they look at the fault.

Always confirm:

• FENSA or CERTASS registration and company registration number
• Individual fitter qualifications and any manufacturer-approved training for the specific profile and low-E glass being fitted
• Public liability insurance, employers’ liability insurance, and any installation guarantees
• How they vet staff and subcontractors, including who’s allowed to sign off a FENSA certificate

Ask for digital copies of:

• Registration certificates (e.g. FENSA) and check them on the official register
• Training records linked to the actual fitters on your job, not just “the company”
• Insurance schedules showing cover limits, policy numbers, and expiry dates
• Written procedures for sign-off: survey, installation, MTC-qualified inspection, certificate issued

Log the date and time you checked each document and keep it with your job file. If anything’s missing, expired, or doesn’t match the name on your quote, treat it as a fault and get it sorted before you pay a deposit or book an installation in Leeds.

Warranty And Guarantees

Your warranty is what you fall back on if a 28mm argon-filled unit starts misting up or a hinge fails, so get it nailed down in writing before you pay a deposit.

Ask for a written warranty spec from both the manufacturer and the installer. It should clearly list:

• What’s covered: frames, A-rated glass units, sealed unit failure, gaskets, multi-point locking, handles and hinges
• What’s not covered: accidental damage, misuse, lack of maintenance, building movement
• The start date and length for each part (e.g. 10 years on frames and sealed units, 2–5 years on hardware)
• Measurable failure criteria, e.g. internal condensation between panes, broken spacer bars, failed Q-LON gaskets

Confirm if labour and call-out charges are included for the full term, or only for the first few years. Get it in black and white who handles what: the fabricator for the glass unit, the installer for fitting issues, and who you ring first if a sash starts dropping or a lock sticks.

Ask about transferability if you might sell the house. Check:

• Can the warranty be assigned to the next owner?
• What paperwork they need (original invoice, FENSA certificate number, warranty document)?
• Any pro-rata reduction on replacement units in later years?

Insist on names, addresses and contact details for the manufacturer and installer, with a simple step-by-step claim procedure and maximum response times for call-outs. Keep the original documents in a safe place, scan them, and if anything in the wording is vague, get it clarified in writing before you sign the contract or book an installation date in Leeds.

Red Flags and Guarantees to Insist On Before You Buy

If you’re checking out double glazing firms, pin everything down in writing and don’t ignore warning signs. You want clear guarantees that cover frame integrity, 28mm argon-filled A-rated sealed units, hardware operation, and installation to FENSA standards, with start and end dates on the paperwork. Make sure hidden defects are covered and that the guarantee spells out exactly what’s repaired or replaced, and on what timescale.

Before you hand over a deposit, confirm it’s protected under an insurance-backed scheme and that the contract is bonded, not just a handwritten quote. Ask for tested U-values, glass thickness, spacer type (e.g. warm-edge), and details like low‑E coating and thermal breaks in the frames, all listed on the contract.

Insist on:

• Installer certification and a FENSA certificate number on completion
• A proper site survey report with final made-to-measure sizes
• A written post-install inspection checklist and sign-off sheet
• Service level timescales for putting right draughts, failed units, or sticking sashes
• Prorated replacement terms and guarantees that transfer if you sell the house

Walk away from vague warranties, verbal promises, or companies that won’t show insurance, references, or previous addresses in, say, Greater Manchester. Record frame and glass unit serial numbers on your paperwork, compare them to the labels at install, and only sign off once everything matches the agreed specification.

Frequently Asked Questions

Can Double Glazing Be Retrofitted Into Listed or Conservation Properties?

Yes, it can be done, but it has to be handled very carefully to keep the conservation officer happy. We normally use slimline double-glazed units in the existing sashes, with discreet beads and reversible fixings, and we’ll supply U‑values, acoustic data and drawings so you can get listed building consent. Expect surveys, maybe a sample window, and a detailed maintenance plan as part of the approval.

How Do Different Glazing Options Affect Indoor Air Quality?

More airtight glazing keeps the heat in but you must think about fresh air. Modern A‑rated double or triple glazing with 28mm argon‑filled units cuts draughts, so you may need trickle vents or a proper extractor system to stop the air getting stale and reduce condensation. A decent installer should advise on vents to keep within current Building Regs and FENSA standards.

Are There Smart or Automated Opening Options for Custom Windows?

Yes, we can fit motorised openers and sensor-controlled vents to most custom windows. We’ll size the motors to suit the sash weight, sort the power supply, and set them up with wall switches or smart controls, plus safe positions for power cuts. During commissioning we adjust travel limits, speed and safety stops, and explain any maintenance needed.

What Maintenance Is Required for Timber Versus uPVC Frames?

Timber needs a bit more looking after: you’re usually sanding and repainting every 3–7 years, and keeping an eye out for any soft spots or flaking paint that could let water in. I’d also check the joints, putty, and ironmongery a couple of times a year, and treat any signs of insect or fungal attack straightaway.

uPVC is easier: a wash down with soapy water every month or so, hinges and locks oiled twice a year, and a yearly check of the gaskets and welded corners is usually enough. Avoid abrasive cleaners, and on both timber and uPVC, sort any condensation issues or failed seals quickly to keep the A-rated units performing properly.

How Do Warranties Transfer if I Sell My Home?

Most warranties will go with the house as long as you follow the supplier’s rules. Usually you fill in a transfer form, send proof of purchase and installation, and contact the manufacturer within their time limit. Keep serial numbers, FENSA certificate and any maintenance records handy, as they may check the register and any past claims before confirming the transfer.