IV68 is the base profile we use for laminated timber windows and doors. It is the standard solution for houses, residences and refurbishments where timber joinery is wanted.
Starting from this profile, every window is made to the actual dimensions of the opening, in the configuration settled for the project.
About the product
The base profile for timber joinery
Laminated timber is made up of layers bonded with alternating grain. This make-up reduces the stresses in the material, and the profile holds its shape better than solid timber, including on long elements.
The configuration is settled project by project: the number of leaves, the hand of opening, the fixed lights, the division and any larger assemblies. We do not work to off-the-shelf sizes.
The species, the shade and the type of finish are chosen for each job, together with the client or the architect.
Benefits
What a laminated timber window brings
IV68 profile
The base profile we use for laminated timber windows and doors.
Laminated timber
Layers bonded with alternating grain reduce stresses and hold the geometry of the profile better.
Configuration to suit the project
Number of leaves, hand of opening, fixed lights and division, all settled for the job.
Actual dimensions
Every window is made to the measured opening, not to a standard size.
Natural appearance
Timber brings a texture and a warmth that other materials do not imitate convincingly.
Finish of your choice
The species, the shade and the type of finish are settled for each project.
Applications
Where it is used
Detached homes
Private residences
Holiday homes
Refurbishment
Heritage buildings
Architectural projects
Technical details
Product data sheet
Material
Laminated timber, lamellae bonded in layers
Construction depth
68 mm as standard; 78 mm to suit the project
Glazing
A double or triple insulating unit, according to the depth chosen
Sealing
Two or three perimeter gaskets, depending on the construction
Glazing
Glazing bead removable from inside
Species
Spruce, pine, larch, oak, meranti, ash
Finish
Stain or opaque coating to a RAL or NCS code, two-tone on request
Hardware
Roto, with surface-mounted hinges; greenteQ handles
Reference for declaration
EN 14351-1
Dimensions
To the measured opening, with no standard size
The 68 mm construction
The window and the door, in the same construction
Two jobs from our own production, built on the 68 mm construction. The data under each photograph are those of the IV 68 construction — the particular configuration is settled for the project.
Window in IV68 construction
A two-leaf window with glazing bars, made to the existing opening of a stone building. The division, the pattern of the glazing bars, the hardware and the finish are settled for each project.
Construction depth
68 mm at the frame and at the sash
Structure
Laminated timber, lamellae bonded in layers
Glazing unit
A double insulating unit; the rebate usually takes units of up to about 34–36 mm
Sealing planes
Two perimeter gaskets, usually in EPDM
Glazing
Glazing bead removable from inside
Door in IV68 construction
A double door with a glazed upper section and solid panels at the foot, fitted to the measured opening. It is built in the same 68 mm construction as the window, with locking at several points around the leaf.
Construction depth
68 mm at the frame and at the sash
Structure
Laminated timber, lamellae bonded in layers
Glazing
Glazing bead removable from inside
Locking
At several points around the leaf
The exact thickness of the glazing unit is confirmed on the profile ordered: the rebate differs from one moulding to another.
Timber systems
The construction depth
The depth of the profile is not a catalogue figure: it decides what glazing unit fits the rebate, how many sealing planes the sash has and how wide the frame reads in elevation.
68 mm construction
IV 68 · The profile we work with routinely
The classic section of the laminated timber window.
It is the reference construction of European timber joinery: 68 mm thick at the frame and at the sash. The rebate takes a double glazing unit, and the profile stays slim enough for buildings where the frame must not assert itself — refurbishments, holiday houses, buildings of architectural character.
Construction characteristics
Construction depth
68 mm at the frame and at the sash
Structure
Laminated timber, lamellae bonded in layers
Glazing unit
A double insulating unit; the rebate usually takes units of up to about 34–36 mm
Sealing planes
Two perimeter gaskets, usually in EPDM
Glazing
Glazing bead removable from inside
Where it fits
Refurbishments and heritage buildings, holiday houses, homes where the slimmest possible frame is wanted. It is also the base construction onto which the external aluminium cladding is fitted.
Worth remembering
The exact thickness of the glazing unit is confirmed on the profile ordered: the rebate differs from one moulding to another.
With double glazing, the 68 mm construction does not reach the thermal level of deeper constructions with triple glazing.
78 mm construction
IV 78 · The step up to triple glazing
Ten extra millimetres that change what fits in the rebate.
The difference from 68 mm is not just the extra timber but the rebate: at 78 mm a triple unit fits. That is where the thermal step comes from, because most of the area of a window is glass, not frame. At this depth class a third sealing plane is added as well.
Construction characteristics
Construction depth
78 mm at the frame and at the sash
Structure
Laminated timber, lamellae bonded in layers
Glazing unit
A triple insulating unit; the rebate usually takes units of about 40–44 mm
Sealing planes
Three perimeter gaskets
Glazing
Glazing bead removable from inside
Where it fits
New houses and refurbishments with a high thermal requirement, large windows, north-facing façades. It is the usual choice when the project calls for triple glazing.
Worth remembering
Triple glazing is noticeably heavier than double. The weight of the sash is calculated before the hardware and the hinges are fixed.
The third sealing plane has an acoustic effect too, but sound insulation comes from the glazing unit, not from the gaskets.
The profile we use routinely is the 68 mm one. The 78 mm construction is settled at design stage, together with the glazing unit: the rebate and the glazing thickness go together and cannot be chosen separately. The glazing thicknesses above are the usual ranges for each depth class and are confirmed on the profile ordered.
Glazing
Which glazing unit fits the rebate
In an ordinary window the glass takes up most of the area. That is why the choice of unit changes the result more than any other decision about the frame.
Ug ≈ 1,1 W/m²K
Double, with a low-E coating and argon
Two 4 mm panes, a 16 mm cavity, one low-E coating, argon fill
The 68 mm construction
Ug ≈ 1,0 W/m²K
Double, with a wider cavity
The same make-up, with the cavity widened to 18 mm
The 68 mm construction, if the rebate allows
Ug ≈ 0,6 W/m²K
Triple, with two low-E coatings
Three 4 mm panes, two 14–18 mm cavities, two low-E coatings, argon
The 78 mm construction
Ug can go below 0.6 W/m²K
Triple, with krypton in narrow cavities
The same make-up, with krypton instead of argon
When the unit has to stay slim
Ug is the declared value of the glazing unit, calculated to EN 673 by the manufacturer of the insulating unit. It is not the transmittance of the window: an installed window also has a frame and a spacer around the edge of the glass, and these change the result. The values above are the usual ones for those make-ups and are confirmed on the data sheet of the unit actually ordered.
Performance
How the values are established
We do not publish a Uw or Rw value for “the timber window”, because no such value exists outside a configuration. Below is exactly what each depends on and what we give you at quotation stage.
Uw — transmittance of the window
It is calculated to EN ISO 10077-1 from the transmittance of the frame, the transmittance of the glass, the thermal bridge around the edge of the glass and the areas of each. The same components give different values on a small window and on a large one, because the frame-to-glass ratio changes.
Uf — transmittance of the frame
It is calculated to EN ISO 10077-2, on the actual geometry of the profile. It depends on the construction depth, on the species and on the make-up of the section. A Uf value taken from another profile does not describe ours.
Ug — transmittance of the glass
It is declared by the manufacturer of the glazing unit, to EN 673. You receive it with the glass data sheet and it does not depend on the joinery.
Rw — sound insulation
It is determined by testing, to EN ISO 10140, and expressed to EN ISO 717-1. The result comes largely from the glazing unit: asymmetric thicknesses, acoustic interlayers and the width of the cavity count for more than the number of gaskets.
The tightness classes
Air, water and wind are classified by testing the assembled element, not the profile. The class is declared for the type of element tested and for the dimensions at which the test was carried out.
What you get from us
At quotation stage we settle the configuration: depth, glazing unit, spacer, hardware and dimensions. The declared values go into the project documentation, for the configuration ordered, not for a catalogue example.
Standards
How to read the classes
Windows and external doors are declared to EN 14351-1. The classes below are the scales from the standards: they show what a figure means, not what a particular product achieved.
EN 12207
Air permeability
How much air passes through the element at a given pressure difference. Class 4 is the tightest.
Class 1
Tested up to 50 Pa · permitted flow 12.50 m³/(h·m²)
Class 2
Tested up to 100 Pa · permitted flow 6.75 m³/(h·m²)
Class 3
Tested up to 300 Pa · permitted flow 2.25 m³/(h·m²)
Class 4
Tested up to 600 Pa · permitted flow 0.75 m³/(h·m²)
EN 12208
Watertightness
Up to what pressure the element keeps water out, under a continuous spray. The letter A means unprotected exposure.
Classes 1A – 4A
Tight up to 0, 50, 100 and 150 Pa respectively
Classes 5A – 7A
Tight up to 200, 250 and 300 Pa respectively
Classes 8A – 9A
Tight up to 450 and 600 Pa respectively
Class E
Over 600 Pa, with the test value declared explicitly
EN 12210
Wind resistance
What pressure the element withstands and how much it deflects under it. The class has two parts: the figure for pressure, the letter for deflection.
Classes 1 – 5
Test pressure 400, 800, 1200, 1600 and 2000 Pa respectively
Deflection A
Relative frontal deflection of no more than 1/150
Deflection B
Relative frontal deflection of no more than 1/200
Deflection C
Relative frontal deflection of no more than 1/300
The class is obtained by testing the assembled element and is valid for the type and the dimensions tested. It does not transfer automatically from one type of opening to another, nor from one size to another.
The material
Species and finishes
The species changes the grain, the weight and the behaviour outdoors. The finish decides how often you come back to the joinery.
Spruce
The species most used in laminated timber joinery: stable, light, with a quiet grain. It takes both stain and opaque finish well.
Pine
A more pronounced grain and visible knots. Chosen where a warm look with an evident texture is wanted.
Larch
Denser and more durable outdoors than spruce, with a warm natural shade. Suited to exposed façades.
Oak
A hard species, with a strong grain and great durability. The usual choice for entrance doors and for heritage buildings.
Meranti
A dimensionally stable tropical species, tolerant of moisture. Used on large elements and in severe exposures.
Ash
A grain close to oak, in a lighter shade. Chosen for interiors where the timber stays on show.
The finishing system
Impregnation
The first coat goes into the timber and protects it against blue-stain fungi and insects. It does not show in the final finish, but without it the remaining coats do not last.
Primer
It evens out absorption and gives the top coats something to key to. At corners and end grain it is applied more thickly, because that is where the timber draws in most.
Wood stain
A transparent or semi-transparent finish: the grain stays visible and the shade is adjusted through pigment. It is renewed periodically, according to exposure.
Opaque coating
An opaque finish, to a RAL or NCS code. It covers the grain, but gives a uniform surface and a complete colour palette.
Two-tone
Inside and outside can have different shades. It is settled before manufacture, because it changes the finishing sequence.
Maintenance
Timber left bare outside needs its finish coat renewing periodically. The interval depends on the orientation of the façade and on exposure, not on a fixed term.
Laminated timber is made from lamellae bonded in layers, with the grain alternating. The make-up reduces internal stresses, and the profile holds its geometry better than solid timber, particularly on long elements. The species above are those we use routinely on external joinery; other species are discussed project by project.
Hardware
The hardware of a timber window
The profile gives the geometry. How well the window closes and how long it lasts depends on the hardware and its adjustment.
Tilt and turn hardware
For timber windows we use Roto hardware, in the surface-mounted hinge version, suited to timber construction.
The weight of the sash
Every hinge has a maximum load capacity. With triple glazing, large sashes reach the limit quickly, so the weight is calculated before the hardware is chosen.
Handles
The greenteQ handles cover the usual range, in plain, button or key versions for windows reachable from outside.
Burglar resistance
The class comes from the assembly: keeps in the frame, enough locking points and a handle of the matching class. It is settled before manufacture.
The complete range, with what each manufacturer declares for its components, is on the page for hardware for timber joinery. The exact codes are settled at order stage, according to the size of the sash and the level of security required.
Hardware and fittings
Hardware and fittings
On IV68 windows we work in two directions, which can also be combined: the modern hardware, which does the locking, and the decorative fittings, which give the traditional look.
Window handles
The handle operates the window hardware. The Roto range covers three design lines, all for windows and balcony doors.
Roto Line
The classic handle line. The manufacturer describes it as having RAL-certified technology for long-term operation, with aluminium components.
Roto Swing
The second design line in the Roto range of handles for windows and balcony doors.
Roto Samba
A handle line with a more rounded design, for anyone who prefers a more discreet look.
For timber windows we use Roto hardware, in the surface-mounted hinge version. Below are the solutions the manufacturer offers for timber joinery.
Roto NX
The tilt and turn hardware system we use on timber joinery. The manufacturer offers it as a modular system, with Roto Sil corrosion protection in class 5 to DIN EN 1670 and certification to EN 13126-8, class H3 — 20,000 cycles.
Roto NX | T hinge
The standard surface-mounted hinge for timber windows, with a sash weight of up to 150 kg. In Roto’s nomenclature it is the surface-mounted hinge for timber, class H3.
Roto NX | Power Hinge
The version for heavy sashes: up to 200 kg on tilt and turn windows and up to 300 kg on bottom-hung-only ones. Still a surface-mounted hinge, still for timber.
Roto NX | TiltSafe
The components that let a window stay tilted without losing its burglar resistance: the manufacturer declares RC 2 in the tilted position.
For doors built in the same timber construction. They are fitted over the frame and over the leaf and adjust in all three directions, including after installation.
Roto Solid S | 117 NN
A two-part surface-mounted 3D hinge, for doors up to 160 kg, on a timber or PVC frame and sash. Lateral adjustment ±5 mm, height +4 / −1 mm and pressure ±0.75 mm, plus ±0.75 mm from the eccentric. CE marking to DIN EN 1935:2002, hinge class 12, SKG** certification.
Roto Solid S | 118 Z
The same capacity, with a pin that can be fitted from either direction — the version to choose when the space between the leaf and the head is small. Lateral adjustment +10 / −5 mm, height ±4 mm, pressure ±0.75 mm plus ±0.5 mm, overlap zone 12.5–27.5 mm. SKG** certification.
The version where all that shows on the edge of the door is a slim cylinder, with the adjustment hidden inside the roller. The manufacturer declares them for timber, PVC and aluminium doors.
Roto Solid B | 218 P
A two-part cylindrical hinge, 18 mm in diameter, for timber, PVC or aluminium doors up to 80 kg. Lateral adjustment ±3 mm, height +4 / −2 mm, pressure ±1.5 mm. CE marking to DIN EN 1935:2002, class 11, ift QM 343 certification, 200,000 cycles, corrosion class 5 to DIN EN 1670.
Roto Solid B | 222 P
The same two-part construction, with a 22 mm roller, for doors up to 120 kg. Suitable for RC 2 burglar-resistant doors, with SKG** certification. CE marking class 13, ift QM 343, 200,000 cycles, corrosion class 5.
Roto Solid B | 318 P
The three-part version, with an 18 mm roller, for doors up to 120 kg. The third part spreads the load over a larger area. CE marking class 11, ift QM 343, 200,000 cycles, corrosion class 5.
Roto Solid B | 322 P
The top of the range: three parts and a 22 mm roller, for doors up to 160 kg. Suitable for RC 2 burglar-resistant doors, with SKG** certification. CE marking class 11 in the rebate or 12 face-fitted, ift QM 343, 200,000 cycles, corrosion class 5.
On an IV68 window with modern hardware, the locking is done by the mechanism concealed in the rebate. The espagnolette fitted to the leaf then has an aesthetic role — it is a dummy espagnolette — and allows the traditional look to be achieved without giving up the performance of today’s hardware. The decorative handles, by contrast, remain functional pieces: they operate the hardware.
MCV F01 and F02 window handles
Handles with a classic design and an operating spindle, for timber windows. F01 with an ornamental rose, F02 with an elongated backplate. They are fitted to the window hardware and operate it.
MCV C01 – C06 espagnolettes
Six espagnolette designs, in brass, bronze and black finishes, with roses and levers of different shapes. They are chosen by the design of the joinery and by the finish of the rest of the hardware.
Complete MCV C7 and C8 sets
The complete set for an espagnolette: the lever, the rose with a keyhole, the rod supports and the rod itself, supplied in the same finish. C7 in black, C8 in patinated brass.
Decorative hinges MCV B01 – B04
Visible hinges, with an ornamental pin. B01 galvanised, B02 and B03 in bronze and patinated brass tones, B04 in wrought black, with a shaped pin. They stay on show on the edge of the window, so they are part of how it looks.
A dummy espagnolette plays no part in the locking and does not change the security class of the window: that comes from the modern hardware, from the keeps in the frame and from the handle. The exact combination is settled at order stage.
Technical documentation
Do you need the technical sections?
The detail sections — head, centre and sill junctions — are not published on the site. We send them on request, for the configuration you are interested in.
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