Softwood Wooden Windows IV68 – Ideal for Renovations

68mm profile, custom-made since 1997

Request a Free Quote Technical Specifications

Uw 1.27 W/m²K

Acoustic insulation

30-36 dB

Acoustic insulation

5 years

Warranty

When IV68 is recommended and when it is not

What is IV68 and when is it the right choice

IV68 is the 68mm profile in the SM Wood range. Built with 3-layer laminated wood and double glazing, it achieves a Uw value of 1.27 W/m²K for the standard 1230x1480mm size (calculated using Spruce with a Uf of 1.36 W/m²K). When using an Oak profile, the Uf rises to 1.88 W/m²K, which directly impacts the final Uw value – the choice of wood species influences thermal performance.
IV68 is the suitable choice in two specific scenarios: replacing or upgrading existing windows where the structural opening limits the profile to 68mm (where IV78 physically will not fit), and secondary buildings without high energy requirements, such as holiday homes, outbuildings, or workshops.
Geometric note: for a small window of 615x740mm, the Uw value rises to 1.39 W/m²K compared to 1.27 for the standard size. The frame occupies a proportionally larger part of the total surface area – an effect that is more pronounced in thinner profiles. Across a project with 10 small windows, this cumulative difference impacts the building’s overall energy balance.

When IV68 is NOT the right choice for you

New builds: A Uw of 1.27 W/m²K exceeds the practical recommendation for nZEB (nearly Zero-Energy Buildings) of under 1.0 W/m²K – IV78 is the correct profile for any new construction.
Primary residences: If the structural opening allows for it, IV78 is the better choice – it provides superior insulation and comfort, and the cost difference is recovered over time through lower energy consumption.
Specific triple glazing requirements: IV68 accepts a maximum of 34mm – standard 40-44mm triple glazing physically cannot fit into this profile.

Technical specifications IV68

All values are from our own production, measured at the standard size of 1230x1480mm.

Parameter	Value
Profile depth	68 mm
Laminated wood	3 layers, D4 adhesive, Class I wood
Standard Uw (1230×1480)	1.27 W/m²K
Uw for small windows (615×740)	1.39 W/m²K
Glazing	Double glazing, up to 34 mm
Ug glazing	1.1 W/m²K
Warm Edge	Included as standard
Acoustic insulation	30-36 dB
Gaskets	2 x Schlegel Q-Lon
Standard hardware	Roto NX, micro-ventilation and basic security
Optional hardware	Concealed, RC1, RC2 upon request
Handles	Hoppe, Dauby, Galbusera, Linea Cali and other brands upon request
Finish	Opaque RAL / NCS or Remmers translucent stain
Warranty	5 years
Lead time	8–12 weeks

Available Wood Species

Spruce – light, dimensionally stable, compatible with any opaque RAL finish, Uf 1.36 W/m²K. Pine – denser with a more pronounced grain, characteristic of traditional architecture, same Uf.

Meranti for direct exposure to precipitation or high humidity: high density, low absorption, and natural resistance without additional treatment. Larch for mountain altitudes – natural hardness and stability during extreme thermal variations. Oak is used exclusively with translucent stains when the grain must remain visible; the Uf rises to 1.88 W/m²K compared to 1.36, impacting the final Uw.

Spruce

Oak

Meranti

Larch

Pine

Reference Projects

We have produced the IV68 for renovations in historic centres, mountain cabins, and outbuildings. Each order began with a specific opening constraint. Exact dimensions, not estimates.

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Customisation

Pricing depends on dimensions and species – request a free quote.

Any size and shape

Any RAL or NCS colour

Dual-colour painting (interior/exterior)

Exterior aluminium cladding

Decorative glazing bars

Concealed RC2 hardware

SM Wood Customer Experience

We only listen to the opinions of people who sleep soundly in their homes during the deepest winter.
Authentic serenity is our greatest testimonial.

Very good. Everything was according to the timelines and expectations!

Florin Lonca
Cluj-Napoca

Excellent! I am very satisfied with the collaboration in every respect: price, responsiveness, execution speed, and quality. I recommend them with confidence.

Marius Moldovan
Residential house project, Cluj

It was great working with smwoodprocom – the finished product was great, and what we expected. They are willing to go the extra mile to meet the client’s needs and are flexible!

Jerome B.
Prébailly, France

Frequently Asked Questions

Wooden windows with double-glazed thermal insulation – 68mm profile, 3-layer laminated wood. Uw 1.27 W/m²K at the standard 1230x1480mm size (value for Spruce). A justified choice for renovations with opening constraints and secondary buildings without nZEB requirements.

IV78 has an additional 10mm of profile depth, an extra gasket, and triple glazing instead of double glazing. The result: a Uw of 0.81 compared to 1.27 – representing 36% less thermal transfer per square metre. IV78 meets nZEB standards; IV68 does not. If the structural opening physically allows for IV78, then IV78 is the correct choice.

Standard: Spruce, Pine, Meranti, Oak. Spruce and Pine are the first choice for opaque finishes. Meranti for humidity exposure. Oak exclusively with translucent stains. Available to order with longer lead times: Larch, Douglas Fir, Ash.

Yes. Annually: cleaning and a coat of wood balm. With periodic servicing, the window can be maintained and refinished. Unlike PVC, wood can be refinished; if PVC degrades, replacement is the only option.

Yes, on request. Fully concealed hardware moves the mechanisms into the inner rebate, with no visible elements from the outside. As standard, IV68 comes with Roto NX (basic micro-ventilation and security included); on request it can also be equipped with RC1 or RC2 resistance classes.

Wooden Windows IV68 – Renovation Profile