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Lacuna Bifold Door Details

Lacuna Bi-fold Doors

We are very excited to supply the Danish-made Lacuna Bi-Fold Doors range.

These stunning wooden bi-fold doors offer unique durability and exceptional performance that is not usually associated with bi-folding doors. We’ve gone into plenty of detail explaining how this is achieved by discussing all of Lacuna’s unique features that contribute to their long-term performance.

We have chosen to add this product to our range, as we feel that it equals the quality of our German products. The product kicks to the curb many of the traditional problems and difficulties which are found when using bi-fold doors in a project. Lacuna really are changing the game.

Bifold Door with Horizontal Glazing Bars
Natural Wood Bifold Open
Lacuna Threshold Runner
Lacuna Doors in Oxfordshire
Oxfordshire Home with Lacuna Door
Bifold Door with Alu Clad Corner Post

Full Details

Further Details:

Lacuna doors offer a totally new approach to bi-fold doors, really bringing the outside in, as well as providing outstanding performance. Performance is so often the failure point of Lacuna’s competitors, with stories on YouTube of leaking and draughty bi-fold doors being commonplace. It must be said that there are very few downsides to this product. One of the more common questions we get asked at Enlightened Windows is whether we can provide an aluminium-clad version. Although the answer is no, the treated timber is designed to be just as low-maintenance. As a result, we believe it is not necessary, and indeed, architects are sitting up and taking note of this solution, as it is so different.

Lacuna products use German-made heat treated beech, with the slimmest profile of any timber bifold door. This timber offers the special characteristic of class 1 durability (very similar to teak) and also offers those all-important low U values in combination with high airtightness. If you want to get technical, see the technical downloads and test data for more information. Unlike many bifold products, this product also offers exceptional airtightness and watertightness.

Lacuna products can be provided either painted or oiled. When using German heat treated timber, painted doors that are not particularly exposed often don’t need further treatment for 20 years. Oiled oak is also available, with this option requiring regular re-oiling.

The painting process used for these exceptional units is founded on automotive manufacturing techniques, with a two-stage prime and sand process with 2-3 layers of finishing paint then used depending on the colour.

Lacuna bi-fold doors are a truly valuable addition to our ever-increasing range of products.

For more details see the attached PDF brochure which gives full details of this exceptional quality product. To make an enquiry, give us a call on 01608 684 607.



Lead Time7-9 weeks
MaintenanceNo further treatment required for 20-30 years
Best U-Value0.7 W/m^2k
FinishesAny RAL Colour, Lacuna have no standard colours and therefore no upgrade costs for non-standard colours
Glazing28mm Double, 38mm Triple, 54mm Triple (Arctic variant),
Obscure, Solar, Laminated, Toughened
Performance and
Airtightness to class 4 standards
Class 1 Durability Timber
Highest quality ironmongery – all hardware is Danish marine-grade materials
Water Tightness to class E1200
Security Tested to EN1627-30/PAS24
Maximum Sizes6m wide, 2.7m high. Each leaf can be up to 1m wide.
Manufactured inDenmark

Configurations and Accessories


Bifold Configuration

We are able to offer a very attractive range of configurations, allowing the doors to be used effectively as simple day-to-day exits and also allowing the user to bring the outdoors in when it suits. Again, this feature redefines what it means to have a bi-fold door. The owner of Lacuna designed the product to eradicate many of the typical objections to using bi-fold doors. Indeed, he even put it into his own home, refining and redesigning the product until he got the design just perfect. This level of attention to detail can only be truly experienced when you use the product. Thanks to this extensive user-testing, Lacuna bi-fold doors are a joy to use.

There is only one rule to follow when configuring Lacuna bifold doors. The number of panels that slide together must be an odd number. This is critical for maintaining the airtightness of the door, but is also important so that you can have a main traffic door.

The 3+0 design gives a main traffic door to one side, whilst still allowing for a large opening area when necessary. The traffic door feature is one that we always include: it allows you to use part of your bifold door as another entrance to your home, without needing to slide any panels around on a day-to-day basis.

3+0 format Lacuna Bifold

The 5+0 design is almost identical in principle to the 3 leaf. Simply adding two extra panels provides a larger opening size, but also allows the option for three resting points when open: 1 leaf open, 3 leaves open or all 5 leaves open.

5+0 format Lacuna Bifold

Arguably, the most versatile configuration is the 3+3. This allows you to have a single entrance door for day to day use. This is a double door that is quick to open, where you can slide either half the panels open, or both halves for a huge opening area.

With any design, we are able to include any number of glazing bars to create a more traditional appearance. These bars do not physically separate the panes of glass, so the class 4 airtightness of the property is unaffected. Instead, bars are adhered to the glass inside and out, and a spacer bar is positioned within the glass unit to give the appearance of a physical break.

3+3 format Lacuna Bifold w Glazing Bars
3+3 format Lacuna Bifold

If you take the normal 3 leaf bifold above, and add on an extra door – forming a double door with the master leaf – this is a 3+1.

Four panel doors, like any doors, cannot have an even number of panels sliding together. This is partly because it would mean the lack of a traffic door, but mostly because it would negatively affect the airtightness of the door.

3+1 format Lacuna Bifold


Lacuna’s straight steel handles are designed to match in perfectly with the hinges, all with a marine-grade coating. If you’re not a fan of the steel finish, then the same ironmongery can be made with a black or a white finish.

Lacuna Internal Thumbturn
External Keyed lacuna door handle
Lacuna Bifold Midway locking handle
Chop Sample
Lacuna Bifold Door Details

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