At what stage should glazing be involved in a project?

As early as concept or planning. Span limits, panel weights, pocket depths and threshold build-ups all influence structure and floor levels. Involving us before the structural design is fixed usually costs nothing; involving us afterwards often costs a steel or a compromise.

Do you provide technical information for drawings and tender packs?

Yes. We supply system sightline dimensions, frame and interlock widths, threshold sections, U-value data and weight schedules so elevations and details are drawn to what will actually be manufactured.

Who takes responsibility for final measurements?

We do. All manufacturing sizes are taken at our technical survey, which supersedes any provisional or drawing sizes. A final configuration pack is issued for written approval before anything is released to production.

Do you offer supply-only to builders?

Our standard model is supply, survey and install, because that is where responsibility stays clear and the outcome is best. Supply-only is considered case by case, but measurement responsibility then sits with the party taking the sizes.

How do you coordinate with groundworks on a flush threshold?

Flush thresholds depend on finished floor levels, external paving levels, structural support and a linear drainage channel in front of the opening. We issue the required levels and drainage provision at survey; the channel itself normally sits within the groundworks scope unless quoted as an addition.

Can you work to a fixed installation window in a build programme?

Yes, provided the opening is formed and signed off in time for survey. Manufacture lead times are confirmed at order and installation is scheduled against scaffold, screed and external works rather than dropped between them.

For Architects, Builders & Developers

Glazing that arrives buildable

Most glazing problems on site were created months earlier, on paper. We work alongside the design and build team so the detail that is drawn is the detail that gets installed.

A specialist inside the team

We are appointed at every stage — sometimes at concept, more often once a scheme is underway, occasionally to rescue a specification that will not build. In each case the role is the same: deliver the glazing element accurately and give the rest of the team information they can rely on.

That means real system figures rather than marketing numbers, honest feasibility rather than optimism, and a clear line around who is responsible for what.

Discuss a project Send drawings

Supporting architects

Design intent, kept intact through to manufacture

Feasibility before it becomes a drawing

Span limits, panel weights, pocket depths and structural implications, given honestly at concept stage rather than discovered at tender.

Sightlines and proportion

Frame widths, interlock dimensions, transom heights and bar layouts, supplied as real system figures so elevations are drawn to what will actually be manufactured.

Thresholds and interfaces

Flush, low-profile and weathered threshold details with the drainage, floor build-up and structural support each one requires.

Heritage and planning-sensitive schemes

Steel-look and heritage systems that pass conservation scrutiny, with precedent from comparable Cumbrian consents.

Aluminium glazing installed on a contemporary Cumbrian extension

The drawing and the installation should be the same thing.

Working alongside builders

Preparation, sequencing and a clear scope

Openings, tolerances and readiness

Confirmed structural opening sizes and tolerances issued after survey, so brickwork, reveals and lintels are formed to the right dimensions first time.

Sequencing that suits the programme

Delivery and installation slotted around scaffold, screed and external works rather than dropped into the middle of them.

Clear scope boundaries

Who forms the opening, who provides the drainage channel, who makes good internally — agreed in writing before anyone is on site.

One point of contact

The same surveyor and project manager from first drawing to sign-off. No handovers, no repeated explanations.

Where we plug in

Six points of contact across a project

01
Concept
Feasibility on spans, weights and pocket construction. What the system can genuinely achieve before it is drawn.
02
Detail design
Sightline dimensions, threshold sections and interface details issued for the drawing package.
03
Pre-construction
Structural opening sizes, tolerances and preparation requirements confirmed with the builder.
04
Technical survey
Final manufacturing measurements taken on site, superseding all provisional sizes.
05
Approval
Final configuration pack issued for written sign-off before release to production.
06
Installation
Sequenced delivery and install by teams who work with these systems every week.

Specification data

Systems, sightlines and thresholds — enough to specify from

The systems we supply, with maximum sizes and weights, tested air, water and wind performance, thermal figures, threshold options and structural notes. Technical drawings, NBS clauses and manufacturer datasheets are available on request for any system below.

Request technical drawings

Cortizo

Ultra-slim sliding and minimal-frame glazing

Spanish-engineered and now one of the most specified names in UK minimal glazing. Cor Vision allows frames to disappear into the surrounding structure so the glass reads almost edge to edge — the system we reach for when the architecture is the brief.

Where it excels: 25mm central interlocks, sashes to 4000mm and up to 94% glazed area
Systems we specify: COR Vision minimal sliders · COR Vision Plus · Corner pocket systems

Minimal-frame corner pocket sliding glazing

Slimline slider open onto a Cumbrian garden

Systems in the range

COR Vision

Minimal sliding

The standard minimal slider: 20mm central interlock, frames buried into floor, ceiling and reveals so only glass is visible from inside the room.

Central interlock: 20mm
Max sash: 2500 × 3000mm
Max sash weight: 320kg
Uw: From 1.1 W/m²K
Configurations: 2, 3 and 4 track, corner and pocket options

COR Vision Plus

Large-format sliding

The large-format development of Cor Vision, engineered for panoramic openings with fully embedded perimeter frames and a glazed surface of up to 94%.

Central junction: 25mm
Max sash height: Up to 4000mm
Max sash weight: Up to 400kg (manual)
Glazing capacity: Up to 56mm
Uw: From 0.9 W/m²K (glass dependent)
Alloy: 6063 T-5 with polyamide thermal break

Figures are manufacturer system data and vary with configuration, glass specification and size. Project-specific U-values, sizes, weights and threshold details are confirmed in writing at design stage — full technical drawings and datasheets available on request.

Alunet

The Aluna range — architectural aluminium, engineered in the UK

Alunet's Aluna range covers windows, bifolds and sliding doors on a single visual language, which makes it our default when a whole elevation — or a whole house — needs to read consistently. Slim sightlines, concealed drainage and marine-quality powder coating, supported by short UK lead times.

Where it excels: 25mm slider interlocks, 2.5 × 2.7m sashes and triple-glazed U-values from 0.9 W/m²K
Systems we specify: Aluna sliding doors · Aluna bifolding doors · Aluna+ windows · Aluna windows

Alunet heritage bifold doors in Lancaster

Five-panel Alunet bifold doors on a cottage extension

Slim aluminium Aluna windows on a Cumbrian elevation

Systems in the range

Aluna Sliding Doors

Slimline slider

Ultra-modern slimline patio door available with 25mm or 50mm interlocking sightlines, engineered for large glass with a very quiet, weighted action.

Interlock sightline: 25mm or 50mm
Max sash: 2500 × 2700mm
Max sash weight: 250kg
Uw: From 1.4 W/m²K
Configurations: 2, 3 and 4 panel, 2 and 3 track, corner options
Security: PAS 24:2022 tested

Aluna Bifolding Doors

BF73 development

A refinement of the proven BF73 folding system with 107mm sightlines, running gear rated for daily use and open-in or open-out configurations up to seven panels.

Sightline: 107mm
Max sash: 1200 × 3000mm
Uw: From 1.1 W/m²K triple glazed
Glazing: 28mm double or 44mm triple
Threshold: Weathered, low-profile or flush
Finish: Marine-quality powder coat, dual colour available

Aluna+ Windows

75mm profile

The premium window in the range: a 75mm frame with a super-slim sash, concealed drainage with no visible caps, and clip-in 'click and forget' beads.

Frame depth: 75mm
Uw: 1.3 W/m²K double / 0.9 W/m²K triple
Drainage: Fully concealed, no external drainage caps
Glazing: 28mm double or 44mm triple, clip-in beads
Styles: Casement, flush casement, tilt and turn, fixed lights

Aluna Windows

73mm / 81mm

The core window system in 73mm or 81mm outer frame depths, including heritage and flush options for period elevations and conservation areas.

Outer frame: 73mm or 81mm
Uw: From 1.4 W/m²K
Energy rating: WER A
Styles: Standard casement, flush casement, heritage
Security: Multi-point espagnolette locking, PAS 24 achievable

Smart Systems

Britain's most widely used aluminium range

Long established, comprehensively tested and supported by a national supply chain. Smart covers the middle ground properly: strong thermal figures, sensible sightlines and hardware that can be serviced for decades rather than replaced.

Where it excels: Proven detailing, national parts availability and heritage-appropriate profiles
Systems we specify: Visoglide Plus · Invisoglide · Visofold 1000 bifolds · Alitherm Heritage

Slimline aluminium sliding doors near Carlisle

Aluminium sliding doors on a brick extension

Systems in the range

Visoglide Plus

Sliding

The workhorse slider: extended polyamide thermal breaks, robust running gear and configurations up to four tracks for commercial-scale openings.

Uw: 1.6–1.4 W/m²K depending on glass
Tracks: 2, 3 and 4 track
Glazing: Up to 40mm, double or triple
Threshold: Standard, low or flush with drainage

Invisoglide

Bonded slider

The bonded-glazing development of Visoglide, giving noticeably slimmer sightlines and enhanced security through structural adhesive rather than beading.

Glazing method: Structurally bonded sash
Sightlines: Slimmer than standard Visoglide
Security: Enhanced by bonded construction, PAS 24 achievable

Alitherm Heritage

Windows

A steel-look casement window designed for period and conservation properties, with slim frames, putty-line detailing and true Georgian bar options.

Appearance: Steel-look, slim sightlines, putty-line profile
Bars: True horizontal and vertical astragal bar options
Uw: From 1.4 W/m²K
Use: Conservation areas and listed-adjacent elevations

Alumil

Precision-engineered European profiles

Newer to the UK, with a long international record on architect-led buildings. The AB-38 remains one of the slimmest bifolds available here, with an 88mm glass-to-glass sightline where panels meet, and the SMARTIA range covers windows and lift-and-slide at genuinely architectural specification.

Where it excels: 88mm bifold sightlines with 1300 × 3000mm panels
Systems we specify: AB-38 slimline bifolds · SMARTIA S560 lift and slide · SMARTIA S67 tilt and turn

Slimline bifold doors on a clad garden room

Architectural aluminium glazing in Kirkby Stephen

Systems in the range

AB-38

Slimline bifold

The slimmest bifold we specify: an 88mm glass-to-glass sightline at the meeting stiles and matching 44mm-frame single and double doors.

Sightline: 88mm glass to glass
Max panel: 1300 × 3000mm
Max sash weight: 140kg
Uw: 1.1 W/m²K (with 0.6 centre pane)
Glazing: 28mm to 44mm
Matching doors: Single and double doors with 44mm frames

SMARTIA S560

Lift and slide

A robust lift-and-slide system for large, heavy sashes where the door needs to feel effortless despite its size.

Operation: Lift and slide or standard sliding
Use: Large-format panoramic openings
Thermal break: Multi-chamber polyamide

SMARTIA S67

Tilt and turn

A 67mm tilt-and-turn window system with a concealed-sash option that reduces the visible aluminium face to 72mm.

System depth: 67mm
Uw: From approximately 1.45 W/m²K
Visible face: 93mm, or 72mm with concealed sash
Max glass: Up to 58mm

The Residence Collection

The credible timber alternative

Where painted joinery is the visual language but maintenance is not welcome. R9, R7 and R2 replicate nineteenth-century timber proportions with mechanically jointed corners, deep sculpted profiles and genuine heritage colourways.

Where it excels: Flush casements and sashes to 0.79 W/m²K triple glazed
Systems we specify: Residence 9 · Residence 7 · Residence 2

Residence 9 windows on a conservation-area property

Residence 7 flush casement windows in grey

Residence 2 windows on a contemporary elevation

Systems in the range

Residence 9

R9 — 100mm

A nine-chamber 100mm system designed to replicate 19th-century timber joinery: flush outside, decorative moulded inside, mechanically jointed corners.

Frame depth: 100mm, nine chambers
Uw: From 1.2 double / 0.8 triple glazed
Energy rating: A+ as standard
Styles: Flush casement, mock sash, bays, shaped and arched heads

Residence 7

R7 — 75mm

Flush inside and out on a seven-chamber 75mm profile — the quieter, more contemporary member of the collection.

Frame depth: 75mm, seven chambers
Appearance: Flush internally and externally
Uw: From 1.2 W/m²K double glazed
Styles: Casements, shaped and bay windows, single and French doors

Residence 2

R2 — 100mm

The aluminium alternative: a flush sash exterior with a square-cut internal shape and equal glass sightlines throughout.

Frame depth: 100mm
Uw: From 0.79 W/m²K triple glazed
Energy rating: Up to A++
Appearance: Square-cut internal shape, equal sightlines

Timber Look Vertical Sliding Sash

Authentic sash movement, engineered in timber-look uPVC

A dedicated vertical sliding sash system for period and conservation-sensitive elevations. Deep bottom rails, run-through horns, slim meeting rails and fully grained sash faces give the read of painted joinery, while spiral balances, tilt-in cleaning and multi-chamber thermals give the building the performance a modern specification requires.

Where it excels: Both sashes tilt in for cleaning; A+ rated with authentic heritage sightlines
Systems we specify: Vertical sliding sash windows · Georgian and astragal bar sashes · Bay and arched-head sash groupings

Timber look vertical sliding sash windows in heritage cream

Vertical sliding sash window in a stone cottage elevation

Systems in the range

Vertical Slider

VS — timber-look uPVC

The core system: two independently operating sashes on spiral balances within a multi-chamber outer frame, with mechanically detailed sash faces and a grained finish inside and out.

Frame depth: Multi-chamber outer frame, deep sculpted sash sections
Operation: Twin spiral balances, both sashes tilt inward
Uw: From 1.2 W/m²K double, 0.9 W/m²K triple glazed
Energy rating: A+ available
Glazing: 24–44mm units, warm-edge spacers, laminated options

Heritage Detailing

Sash proportions

The details that decide whether a replacement sash reads correctly from the pavement — specified per opening rather than as a standard product.

Sash horns: Run-through and stub horn options
Meeting rail: Slim mid-rail to hold authentic sightlines
Bars: Georgian, astragal and duplex bars, internal and external
Bottom rail: Deep bottom rail matching period joinery
Hardware: Monkey-tail, teardrop and fitch fasteners; chrome, brass, black

Shaped and Grouped Openings

Bays, arches, mullioned runs

Sashes coupled into bays, mullioned runs and beneath fixed arched heads, with bar layouts aligned across every light in the group.

Configurations: Single, coupled pairs, three and four-light bays
Heads: Fixed arched, segmental and cambered heads above sliding sashes
Couplers: Structural mullion and transom couplers, colour matched

Nordic Aluclad

Engineered timber core, powder-coated aluminium cladding

Scandinavian aluclad construction: a solid engineered timber structural frame with a powder-coated aluminium skin clipped to the external face, free to move independently of the timber. The internal reveal reads as joinery; the external face is maintenance-free coated aluminium. Available across windows, entrance doors, French doors and lift-and-slide sliding doors within one frame family.

Where it excels: Uw from 0.8 W/m²K triple glazed with a genuine timber internal face
Systems we specify: Aluclad windows — Classic and Softline profiles · Aluclad entrance and French doors · Aluclad lift and slide sliding doors

Aluclad window with timber internal reveal in a contemporary room

Aluclad lift and slide sliding doors onto a coastal terrace

Aluclad frame corner detail showing timber and aluminium junction

Systems in the range

Aluclad Windows

Classic / Softline

Six opening functions on a common frame family. Classic carries a softly moulded external face for traditional elevations; Softline is square-cut for contemporary work. Both share the timber core, cladding system and performance.

Construction: Engineered Scandinavian timber core, clipped aluminium external cladding
Uw: From 1.2 W/m²K double, from 0.8 W/m²K triple glazed
Opening types: Fixed, side hung, side guided, top guided, tilt and turn, fully reversible
Glazing: Argon-filled double or triple, warm-edge spacer, soft-coat low-e
Glazing bars: Bonded 24mm, 42mm or 60mm with matching internal spacer
Ventilation: Clickvent trickle vents, white, aluminium or dual colour

Aluclad Entrance Doors

Solid leaf, PAS 24

A solid engineered timber leaf with a bonded aluminium outer skin in a made-to-measure frame, single or double, opening in or out, with optional sidelights and toplights.

Leaf: Solid engineered timber core with bonded aluminium skin
Ud: From 1.0 W/m²K depending on glazed area
Security: PAS 24 tested, Secured by Design, triple-point locking as standard
Glazing: Toughened or laminated, clear or obscure, double or triple
Hardware: Stainless pull bars 800mm to full height, or matched lever sets

Aluclad French Doors

Single / double leaf

Externally glazed single or double sets opening inward or outward, with shoot bolts to the slave leaf and sidelights aligned to the same sightline as adjacent windows.

Ud: From 1.1 W/m²K
Configurations: Single or double leaf, opening in or out, optional sidelights
Security: Triple-point locking, laminated glass where accessible
Threshold: Standard or low threshold subject to exposure and linear drainage

Aluclad Sliding Doors

Lift and slide

Two-part and four-part lift-and-slide screens. The handle lifts the panel clear of its seals before it travels, then drops it back onto them — giving a heavy panel light operation and a hard seal when closed.

Ud: From 1.1 W/m²K, triple glazed
Configurations: Two-part or four-part, straight run or bi-parting
Operation: Lift and slide gear, single-handed operation on large panels
Security: Triple-point locking, laminated glass where accessible

Specialist specification

Fire rated internal steel doors

Certified FD30 and FD60 steel-look doorsets, specified from the same collection as the unrated doors so a compartment line does not interrupt the interior. We support the door schedule from concept through to the certification handed over at completion.

Fire rated technical page Request the specification pack

Fire rated steel-look doorset with side and over panels

Technical specifications
FD30 and FD60 doorset data, tested to BS 476-22 or BS EN 1634-1, with the scope of certification stated rather than implied.
CAD and detail drawings
Head, jamb and threshold sections in DWG and PDF, dimensioned to the manufactured profile.
Fire certification guidance
Test reports, assessments and third-party certification collated for the Building Control file.
Frame details and wall build-ups
Compatible stud, blockwork and SFS build-ups, with fixing centres, packing and gap tolerances.
Hardware schedules
Hinges, latches, closers and seals issued as a tested set, ready to drop into the door schedule.
Glass specifications
Certified clear, reeded, obscure, satin and acoustic laminate build-ups with pane size limits.
Acoustic options
Laminated acoustic glazing to around 38dB Rw where a rated opening also needs to be quiet.
Installation sequencing
When rated doorsets should arrive relative to plastering, flooring and second fix, and what must be in place first.
Early-stage specification support
Mark up the door schedule with us at detail design and the rated openings stop being a late substitution.

Certification applies to the tested assembly. Substituting hardware, glass or the wall build-up outside the tested scope invalidates the evidence, so we prefer to agree the schedule while it is still on paper. Read the specification guide.

Trade questions

What design and build teams ask us

Responsibility, information, sequencing and thresholds.

Talk To Our Technical Team Visit the Knowledge Centre

Begin

Send us the drawings.

Plans, elevations or a sketch on a phone. We will come back with feasibility, indicative sightlines and where the specification needs attention.

Book a Home Design Visit Request a Quotation

Glazing that arrives buildable

A specialist inside the team

Design intent, kept intact through to manufacture

Feasibility before it becomes a drawing

Sightlines and proportion

Thresholds and interfaces

Heritage and planning-sensitive schemes

Preparation, sequencing and a clear scope

Openings, tolerances and readiness

Sequencing that suits the programme

Clear scope boundaries

One point of contact

Six points of contact across a project

Concept

Detail design

Pre-construction

Technical survey

Approval

Installation

Systems, sightlines and thresholds — enough to specify from

Cortizo

COR Vision

COR Vision Plus

Tested performance

Thresholds and floor build-up

Structural coordination

Finishes and glazing

Alunet

Aluna Sliding Doors

Aluna Bifolding Doors

Aluna+ Windows

Aluna Windows

Tested performance

Thresholds and interfaces

Sizes and structural notes

Finishes, glazing and hardware

Smart Systems

Visoglide Plus

Invisoglide

Alitherm Heritage

Tested performance

Thresholds and interfaces

Long-term serviceability

Alumil

AB-38

SMARTIA S560

SMARTIA S67

Tested performance

Thresholds and interfaces

Specification notes

The Residence Collection

Residence 9

Residence 7

Residence 2

Performance and compliance

Heritage and planning

Colours and finishes

Timber Look Vertical Sliding Sash

Vertical Slider

Heritage Detailing

Shaped and Grouped Openings

Performance and compliance

Specification notes for architects

Colours and finishes

Nordic Aluclad

Aluclad Windows

Aluclad Entrance Doors

Aluclad French Doors

Aluclad Sliding Doors

Performance and compliance

Specification notes for architects

Colours and finishes

Fire rated internal steel doors

Technical specifications

CAD and detail drawings

Fire certification guidance

Frame details and wall build-ups

Hardware schedules

Glass specifications

Acoustic options