London's housing stock is a patchwork, from Georgian terraces in Islington to sixties obstructs in Haringey and new-build penthouses in Nine Elms. Good glazing sits at the intersection of thermal performance, preparing restrictions, and day-to-day usefulness. I've invested over a years specifying doors and windows on jobs throughout the capital, from modest window replacement in Walthamstow to bespoke aluminium curtain walling in the City. What follows is not a copy-paste directory site. It's a practitioner's view of ten double glazing business in London worth knowing, with the context you'll require to make informed choices.
Before the list, a word on credentials. For domestic window replacement in London, insist on FENSA or CERTASS self-certification for Building Regulations compliance. Ask for BFRC-rated units if you desire documented energy performance. For sanctuary, experience with Article 4 Instructions and local planning officers matters as much as U-values. Likewise, be clear whether you require supply-only from a double glazed units manufacturer, or a full style, survey, and set up service from a doors and windows supplier.
What actually makes a glazing company "finest" in London
The phrase "best double glazing suppliers" is too broad without context. In a Victorian bay in Hackney, the very best might be a timber sash specialist with slimline double glazed systems and putty glazing that passes conservation analysis. For a contemporary extension in Richmond, it might be a thermally damaged aluminium fabricator delivering a 7-panel bifold door with appropriate drain and low limits. And for a Notting Hill estate flat, it may be an internal secondary glazing firm that soothes street sound without falling foul of leasehold restrictions.
I take a look at 4 axes. First, product variety: UPVC doors and windows for affordability and low maintenance, aluminium doors and windows for slender aesthetic appeals and sturdiness, and genuine timber options for duration homes. Second, performance: low-E glass, argon gas double glazing, warm-edge spacers, and airtight setup. Third, compliance and guarantee: FENSA or CERTASS documentation, insurance-backed assurances, and glass that satisfies EN 1279 and PAS 24 where required. 4th, service: surveys that capture reveal depth and lintel problems, installers who effectively load and foam without bridging moist, and aftercare that answers the phone.
The list at a glance
Some readers want the names quickly, then the subtlety. Here's the lineup I've dealt with or benchmarked carefully across projects in London. These are blended in nature, from full-service installers to specialist fabricators and custom window manufacturers.
- Anglian Home Improvements Everest SEH BAC AluK-approved London fabricators Reynaers in your home partners across Greater London Schüco fabricators serving North and West London The Sash Window Workshop Express Bi-Folding Doors, London showroom Fineo/ Heritage slimline double glazing partners Secondary Glazing experts such as Granada in London
Keep reading for where each shines, the risks to see, and truthful talk on expense and lead time.
Anglian Home Improvements
For domestic double glazing in London, Anglian remains a safe pair of hands for UPVC windows London and UPVC doors London, plus composite front doors and back entrances. They bring FENSA accreditation, deal BFRC-rated alternatives, and know their method around typical London wall constructions, whether cavity brick in Barnet or solid brick in Lewisham.
What I like: their UPVC casements accomplish low U-values with argon-filled systems and low-E glass, and they can spec drip vents that please Part F without turning your lounge into a wind tunnel. Their sealed units are consistently manufactured, and their installers normally appreciate sill end dams and DPCs. For house owners after budget-friendly double glazing London without the inconvenience of vetting a little specialist, Anglian is a practical choice.
What to see: with national firms, the sales representative is not the property surveyor. Book a correct technical survey and push for details on sightlines and bead type. Make certain the profile and handle surfaces match throughout your home. On bay windows in Lambeth and Southwark, examine whether they're restoring structural bays or setting up within lumber frames. Warranties are solid, however getting a quick service call during peak season can take persistence.
Everest
Everest is comparable in scope to Anglian, with strong protection of doors and windows suppliers London and a track record for robust, secure units. They lean into security specifications like PAS 24 and Guaranteed by Design on demand, which works for ground flooring flats in Camden or high-traffic locations near transport hubs.
From an energy viewpoint, their BFRC ranked glazing suppliers status is trustworthy, and their triple glazing still gets here with reasonable sightlines. That stated, triple glazing is heavier and not always the most efficient choice once you account for frame conductivity. A great Everest surveyor will discuss when thermally broken aluminium windows with high-performance double glazing outperform heavy triple in real-world London use.
Do request for verification of drain paths for sliding doors London, especially on flush limits resulting in patio areas. The British weather is one thing, however London's mix of clay soils and sluggish drainage in back gardens indicates you require a clear plan for stormwater that does not feed back under your door.
SEH BAC
SEH BAC sits conveniently in the relied on glazing specialists London group, providing UPVC and aluminium throughout Greater London, with an excellent record on conservatories and orangeries. While conservatories have actually ceded ground to flat-roof extensions with big rooflights, SEH BAC still hold their own on intricate frames and roofing drainage.
Their aluminium range consists of thermally broken profiles, frequently AluK or comparable, with gaskets that actually seat well after modifications. That matters when installers are tweaking panels throughout a Bayswater basement conversion with restricted gain access to. They likewise manage French doors London and outdoor patio doors London with good threshold options.
SEH BAC is CERTASS authorized, and their paperwork tends to get here on time. Pricing sits mid-market. On heritage tasks in Haringey or Islington, they partner or subcontract to timber professionals if the council leans conservative on glazing bars and sightlines.
AluK-approved London fabricators
Some of the best aluminium windows London come via local producers authorized by AluK. These are not family names, but they make and set up to a regularly high standard. I've utilized AluK profiles for bespoke aluminium doors London that needed slim mullions without compromising stiffness. For aluminium bifold doors London, AluK's BSF70 still delivers tight stacking and reliable rollers, provided the opening is square and the track set on a strong pad.
Working with a producer suggests you can have made to measure windows London with odd angles, important blinds, and powder-coated surfaces that match RAL or perhaps anodic look. Preparations range from 4 to 10 weeks depending on powder coat and glass. Make sure you specify warm-edge spacers and argon gas double double glazing suppliers glazing as basic, and discuss acoustic interlayers if you're near the Overground in Shoreditch.
Ask the producer to offer wind load and deflection calcs for high sliders in exposed positions. London might not be seaside, but wind funnelling around high increases in Stratford is real, and large panels can breathe more than customers expect.
Reynaers in the house partners
Reynaers is a premium aluminium system with strong aesthetics and hardware. Their moving doors London range, particularly CP 130 and CP 155, moves well under load and accepts large panes that make designers happy. For modern-day window styles London, Reynaers repaired lights paired with opening sashes give a clean, continental look that suits modern extensions in Wandsworth and Ealing.
In practice, the distinction between Reynaers and a mid-market aluminium system reveals at corner joints, gasket consistency, and hardware durability. Cheap rollers pass away young when grit gets into tracks throughout London's relentless structure works next door. Reynaers' thermally broken aluminium windows tend to hold up, offered the track is safeguarded throughout construction and the drain slots are kept clear.
Costs sit above average. Anticipate to pay a premium for anodised-like finishes and structural glazing junctions. If your specification requires a pocket slider disappearing into the wall, bring in a structural engineer early. These are information I have actually seen blow budget plans in Battersea due to the fact that the cavity space was not planned at the shell stage.
Schüco fabricators serving North and West London
Schüco is the byword for high-end aluminium in London, often appearing in architect-led projects in Kensington and Hampstead. Tilt-turn windows with true thermal breaks, crisp mitres, and outstanding seals make them a leading option when airtightness testing becomes part of the brief. On Passivhaus-inspired refurbishments in Hounslow or Barnet, I have actually determined U-values in the 1.0 to 1.3 W/m ² K variety with double glazing, lower with triple, presuming proper installation and low-E coatings.
The trade-off is cost and lead time. Schüco moving systems are beautiful however unforgiving if the base develop runs out tolerance. Tolerances in the millimetres matter, and you need installers who comprehend packers, silicone types, and pressure equalization. Pick a London doors and window company with a performance history of Schüco installs and ask to see a just recently finished job, not just a showroom panel.
The Sash Window Workshop
For period homes, The Sash Window Workshop is a professional worth knowing. They produce lumber sash and sash windows that meet with approval in sanctuary and with choosy preparation officers in Greenwich, Richmond, and Kensington and Chelsea. Slimline double glazing with heritage putty sightlines can be accomplished using units around 12 to 16 mm in general, in some cases with vacuum glazing like Fineo where spending plans allow.
Their installers know how to deal with wonky brick reveals, and they'll draft-proof effectively so you don't lose the gains of energy efficient windows London through leaking frames. Lumber is greater upkeep than UPVC, yes, however excellent micro-porous paints and yearly checks make it workable. For leaseholds, they can often provide joinery details that help with freeholder approvals.
One caveat: slimline systems have less argon volume, and warm-edge spacers can be trickier at thin sightlines. They still perform far better than single glazing, but they won't match a chunky 28 mm system in a UPVC frame. If you require top-tier thermal performance, think about secondary glazing behind initial sashes or high-spec timber frames with much deeper areas where planning permits.
Express Bi-Folding Doors, London showroom
Express concentrates on huge glass: doors that open up a cooking area extension to the garden, rooflights, and sliders. Their aluminium doors feel strong, with decent locking and finish options. The London display room assists clients choose between bifold doors London and large-format sliders by feel, not simply brochures.
On bifolds, my general rule depends on 6 panels before you consider changing to a slider. More panels imply more stiles, which interrupts the view and increases points of prospective misalignment. Express' installation groups are disciplined about setting levels, but the base needs to be right. On clay-heavy ground in Enfield, think about a strengthened piece or steel to keep the track real over time.
If you want flush sills, accept that perfect flush is compromised in UK weather condition. Choose a slightly happy internal limit with external falls away, proper drainage, and you'll prevent winter pooling. Ask Express to reveal you their limit sections and how they integrate with your floor build-up, insulation, and damp proof membranes.
Fineo and heritage slimline double glazing partners
Vacuum-insulated glazing like Fineo has actually altered the conservation conversation. You can achieve double-glazing-level thermal efficiency in an unit as thin as 6.7 mm, which can be retrofitted into existing lumber sashes in specific cases. London districts with stringent aesthetic appeals have been more available to these services when provided with cautious joinery details.
Expect higher expense per square metre, and understand the lead time. Consider acoustic laminates if you are on a busy road in Hammersmith. With vacuum glazing, edge conditions and dealing with are crucial. I recommend customers to use an installer who has done at least three tasks with the picked brand and will ensure no racking of frames throughout installation.
Secondary glazing professionals such as Granada
Where leasehold limitations or planning constraints block external changes, secondary glazing is typically the best course. Firms like Granada supply aluminum-framed internal systems that cut noise and improve thermal convenience without changing the outside. In Westminster and parts of Camden, I've used secondary glazing to halve the nightly bus sound with minimal visual impact.
Thermally, secondary glazing traps an insulating air layer. Integrate it with low-E glass on the secondary pane and you can get near double glazing performance. The trick is making sure ventilation technique still works. If you block trickle vents, you may need alternative background ventilation to fulfill Part F and keep condensation at bay.
How these business stack on materials: UPVC, aluminium, and timber
UPVC windows and doors are the foundation of cost effective double glazing London. They offer reputable U-values around 1.2 to 1.4 W/m ² K with argon-filled double glazing and low-E glass windows. They are low upkeep and suitable for many properties outside rigorous heritage zones. Drawback: bulkier frames and restricted colors, though foils have actually improved.
Aluminium windows and doors control modern-day schemes. Thermally broken aluminium windows utilize polyamide thermal breaks and can match UPVC on U-values while keeping slim sightlines. End up quality with powder-coating is outstanding, and they pair well with huge openings: moving doors, corner postless setups, and bespoke aluminium doors London. The primary disadvantages are cost and the requirement for accuracy on site.
Timber remains important for duration residential or commercial properties and discerning visual appeals. With quality wood and paint, life expectancy is long. Coupling with vacuum or slimline double glazing produces energy performance in windows and doors without ruining character. Needs upkeep discipline and a skilled installer who respects the grain, sealing, and drainage.
Energy efficiency and BFRC scores that in fact matter
BFRC rankings provide a heading energy score, however I motivate customers to take a look at the U-value of the whole window, not just the glass. Ask for the U-value of the entire system, consisting of frame and spacer. Warm-edge spacers minimize thermal bridging, and argon gas double glazing is the baseline today. Krypton can help on really thin cavities, though expense increases sharply.
On south-facing elevations in Bromley or Croydon, consider solar gain. A lower g-value keeps summer season spaces comfy, however it can reduce passive winter heat. Stabilize the numbers based upon space usage and shading from trees or neighbouring structures. Acoustic laminates help if you're near railway, though they nudge U-values slightly.
Installation quality can swing efficiency by 10 to 20 percent in practice. Broadening foam, airtight tapes at the boundary, and proper packer positioning are what stop draughts. I have actually seen exceptional BFRC-rated systems underperform due to the fact that the reveal was never ever sealed behind the trims.
Navigating London's rules: FENSA, CERTASS, and preparing sensitivities
For most domestic window replacement London, FENSA or CERTASS self-certification is the route. You'll get documentation that satisfies Building Control, covering security glazing in critical areas, ventilation, and thermal compliance. For flats, secure freeholder authorization and consider fire safety egress on bed room windows, especially in older conversions.
In sanctuary, speak with the local planning authority early. Richmond, for example, can be particular about glazing bar widths and putty lines. Islington typically desires slim sightlines and timber on primary elevations. Kensington and Chelsea might request historical profiles, not simply any timber sash. An excellent business will offer section details and sample frames to assist your case. For listed buildings, secondary glazing is typically the only sensible route.
Realistic rates, lead times, and pitfalls
For a normal semi in Haringey, expect a ballpark of ₤ 5,000 to ₤ 9,000 for UPVC casements and a front door, supplied and set up by a credible FENSA-certified window installer. Aluminium windows might land between ₤ 8,000 and ₤ 15,000 for equivalent openings, depending upon spec and finishes. A large-format 3-track slider in aluminium can be ₤ 6,000 to ₤ 12,000 by itself once you add toughened glass, low thresholds, and website cranage.
Lead times: UPVC often 3 to 6 weeks post-survey. Aluminium 6 to 12 weeks, longer for unique surfaces or complex sliding systems. Lumber and heritage glazing can reach 10 to 16 weeks, and secondary glazing normally 4 to 8 weeks.
Common risks I see in London homes: not enabling steel lintel upgrades in widened openings, bad drainage at thresholds, undervaluing the effect of stack vents and extract fans on internal pressure that motivates draughts, and mis-specified trickle vents that whistle on windy days in exposed terraces.
Picking the best partner for your project
If you desire a one-stop windows and doors supplier who will determine, produce or acquire, set up, and self-certify, Anglian, Everest, and SEH BAC fit that short. If you're going for modern, custom-made window makers London with aluminium systems like AluK, Reynaers, or Schüco will give you the clean lines and performance you're after, backed by system service provider warranties. For heritage, The Sash Window Workshop and Fineo-linked partners are strong. For leaseholds and listed settings, secondary glazing experts lead the way.
One test I utilize: ask for specific details. For instance, what spacer bar and gas fill will you supply as requirement? How are corners sealed on the frames? What is the documented U-value of the whole window, not just the glass? How will the cill satisfy the brickwork or render, and what is your plan for air sealing the inner expose? The very best double glazing providers in London response clearly without hand-waving.
A useful path from short to signed contract
Here is a compact sequence that keeps London tasks on track, specifically when handling contractors, architects, and deadlines.
- Define restrictions first: leasehold approvals, sanctuary status, structural opening sizes, and ventilation needs. Collect photos and a simple schedule of openings. Shortlist 3 companies aligned to your materials and visual. For aluminium, choose system-led fabricators. For heritage, pick timber or vacuum glazing specialists. Request technical quotes with area drawings, whole-window U-values, spacer specifications, g-values, and installation approach declarations. Evaluation preparation honestly against your programme. Visit a completed local job when possible. Display rooms help, however set up examples expose sealing quality, drainage, and real-user feedback. Lock information early: hardware, colours, trickle vents, thresholds, and glass alternatives like laminated acoustic or solar control. Verify FENSA or CERTASS process and guarantee documents.
Final thoughts from the website side
I've had doors craned over narrow mews in Westminster, sashes alleviated into bays where absolutely nothing was level, and sliders adjusted on a winter season afternoon when the track packed with grit from a neighbour's construct. The common thread in effective London installs is preparation and detail. The companies noted here have repeatedly provided strong outcomes across the boroughs, however the best fit depends upon your home, budget plan, and tolerance for maintenance.
Whether you want energy effective windows London for a draughty balcony in Fulham, a statement aluminium slider for a cooking area in Dulwich, or trusted double glazing providers who won't disappear after deposit day, align your option with the truths of your job. Inspect the certifications. Check out the specification beyond the brochure. Ask to see a task completed in the last six months. And keep in mind that the efficiency of any window or door, no matter how well ranked on paper, lives or passes away at the interface between frame and wall. That's where great business make their keep.
Doorwins
Address: Office 11, Dearden House, W Gate, London W5 1BS
Phone: 020 8629 1250
Doorwins Windows and Doors is among the leading aluminium glazing companies in London. We specialise in manufacturing and installing bespoke bifold doors for residential and commercial projects.
Each project delivered by Doorwins highlights why Doorwins remains a trusted brand in London’s double glazing industry. Whether you need slimline aluminium windows, we’ll recommend and install the perfect system.
As London’s trusted glazing company, we maintain our reputation by delivering transparent service, competitive pricing and guaranteed aftercare.
uPVC & Aluminium Styles: uPVC flush casement windows; uPVC front doors; roof lanterns. Aluminium heritage windows; aluminium inline sliding doors; roof walk-on glass. As a London double glazing supplier, we provide design, manufacture and installation for residential and commercial projects, covering replacement windows, new-builds, extensions, and refurbishments.
Doorwins windows and doors
Address: 4 Observatory Gardens, London W8 7HY
Phone: 020 8629 1171
AREAS COVERED: Kensington, Chelsea, Knightsbridge, Belgravia, Mayfair, St John’s Wood, Maida Vale, Marylebone, Hampstead, Highgate, Primrose Hill, Belsize Park, Notting Hill, Holland Park, Chiswick, Kew, Richmond, Barnes, Putney, Fulham, Hammersmith, Ealing, Acton, Brentford, Wimbledon, Southfields, Battersea, Clapham, Wandsworth, Balham, Tooting, Dulwich, Blackheath, Greenwich, Canary Wharf, The City, Shoreditch, Islington, Angel, Hoxton, Camden, Swiss Cottage, Golders Green, Hendon, Mill Hill, Stanmore, Edgware, Harrow, Pinner, Ruislip, Uxbridge, Twickenham, Kingston, Surbiton, Teddington, Sunbury, Staines, Watford — full coverage across NW & SW postcodes.