In the Old Continent, the slide-out has always been chased, with mixed results, almost exclusively by the most prestigious, Germany-manufactured vehicles: high-class overcabs and motorhomes, made with no expense spared to meet any possible requirement. Over the years, the proposals by Niesmann+Bischoff, Concorde, Morelo, RMB, various Mobil or Volkner-Mobil, only to name a few, have been and are quite different: luxury motorhomes, with large interiors guaranteed by lengths even of 10 or 11 meters, designed to be actual suite on wheels to be used in long travels for several months each year, often cleverly adjusted by German specialist Klaus Hunerkopf. From the prestigious atelier of Neukirchen, in fact, interesting changes made on various Flair, Palace and Charisma come, almost all marked by a left side slide-out on the passenger compartment front, with a length of at least 250 cm and designed to accommodate the traditional side sofa as well as the equally classic kitchen block. Unique solutions, of course, that on vehicles already featuring a width higher than the average, inevitably ensure a large inner space, transforming a modern bar/executive style living in an actual living room offering the maximum space for a pleasant and relaxing wellness. In this regard, one of the most recent achievements of Hunerkopf, a Concorde Charisma 920 which the atelier has installed three extensibles on, is exemplary: beside the classic one, aimed at the living room, we have two additional ones, symmetrical, in the rear area of the passenger’s compartment, dedicated to the sumptuous bedroom with double nautical bed in the centre over the car garage. Vehicles featuring maximum prestige and maximum customizing possibility deserve the maximum of the technology: these vehicles use particularly sophisticated materials as the carbon fiber, thus ensuring extreme robustness, lightness and aesthetic perfection but requiring adequate investments, often charged to the final customer, with figures very close to 30,000 Euro per single vehicle. A price that, of course, represents a further total cost increase even for vehicles whose list price is already far over the 200,000 Euro, but that becomes utterly unfeasible for mainstream vehicles where it would almost double their regular price. Yet, even in this class, there’s no shortage of proposals.

Starting from the early 2000s, several manufacturers have invested resources in the variable volume cockpits development: first and foremost Frankia that with the pioneering Vario-Space has introduced side and/or rear slide-out even on six meters overcabs, low profiles and motorhomes, generally using the extensible for the location of the always ready double bed (on more compact cabins) or, on the larger ones, nestled first on Fiat Ducato equipped with AL-KO AMC chassis and subsequently on the more performant Iveco Daily 70C, in the rear part, aimed at the living, with a side sofa ready to transform itself, during a stop, in an actual chaise longue. Frankia 670 GD VS featured a rear room with garage space and, on top of this, a cross double bed inside of the slide-out which, when removed, allowed for the transformation into twin beds. Absolutely ingenious, the idea proposed by Frankia was in need of an extremely sturdy structure. Actually, the removable portion covered not only the slide-out, but also the entire rear wall, with a double wall (internally fixed and externally removable, properly supported by major longitudinal members and sliding rails below, placed under the bottom floor and solidly connected to the vehicle TO-KO AMC chassis, which the traditional automatic-extractable veranda was added to, designed to protect the upper portion of the fundamental gaskets and enable them to ensure the seal as needed. A technically valid as well as stylistically acceptable solution, thanks to a good integration of the extensibile, even though the presence of a double wall and, consequently, the necessary lower supporting tools, hardly could be compatible with a total mass within the canonical 3,500 kg limit. France , however, is not the only manufacturer committed to democratizing the slide out: probably less famous, but equally important, were the attempts Knaus has made over the years, who equipped the version 750 TS with an extendable side wall designed to increase the available living area space, with the whole U-shaped side dinette that, protruding 50 cm along the left wall, significantly increased not only the interior space but also and especially the usable surface of the living and, consequently, of the double bed made available through its transformation. This is a particularly interesting example, because Knaus made this solution available not only on the flagship Eurostar series, but also proposed it in conjunction with the less expensive and sophisticted Azur and Sudwind: in 2001, the extensible movement system was manual and the extensible was located just above the double central axis to ensure a good weights balance. Obviously, many things have changed since then. The Knaus Group was not the only one to install the slide-out on a caravan. In 2012, the brand Eterniti presented the Genesis IB 4 at NEC in Birmingham, a dual axis luxury caravan also characterized by an extensible side aimed at increasing the space available for the bedroom and kitchen block, while even more extreme was the innovative BeauEr 3X, a super small caravan produced by the French company Beauer, which was characterised not only by one slide-out, but from a real telescopic body that, during stops, literally triples the habitable volume, exactly as the model naming, 3X, points out. A habitable volume that triples, then, by not expanding both on the right and left side for the canonical 50 or 70 cm of the conventional slide-out, but for the entire vehicle width, with the floor area increasing, in less than a minute, from 4 to 12 square meters. With an almost quiet beginning, this caravan-concept proposed by the French company brings with it a true radicalisation of the extensible space concept, while providing an interesting interpretation of the “downsizing on the road” and “upzing when necessary” concepts on which anybody would agree, ensuring everything that usually appears irreconcilable, i.e compactness on travel in favor of ease (and cost) on stops, amplitude, and habitability during stops, and that may not be limited to the small caravan 3X: BeauEr, in fact, is about to propose the concept combined with both a larger size caravan (i.e. featuring a floor area of 27 square meters), the 3X+, and a motorized, the 3XC.

Almost fifteen years later, it is again a caravan proposed by the KnausTabbert group to believe in the possibilities the slide-out offers. Tabbert’s production flagship, the Cellini 750 HTD, is indeed available both in “standard” version and extensible wall-equipped one: with electric up-down system and based on the tried and tested Lippert In-Wall Slide-Out system which is no longer only aimed at extending the living usable surface, but at significantly increasing the entire caravan internal space, with block kitchen and bedroom featuring cross central double bed that come out transforming an already sophisticated room into a real maxi suite. The price difference between Cellini 750 HTD and Cellini 750 HTD Slide-Out amounts to about 14,000 Euro: a certainly remarkable surcharge, which brings the price of this product to compete in an absolutely elite range, but that makes us to consider two aspects. The first is given by the system weight, which, including the necessary changes to the inner layout (with a different arrangement of the double bed), is approximately 400 kg compared to the homologous standard model, while the second, very practical, concerns the heating system: a significantly sized slide out is to notably increase the vehicle internal volume and, as a consequence, the air volume to be heated. Therefore, the cockpit needs a more powerful heating system. Therefore, Tabbert, on the only extesible-equipped version, uses a second stove (electronic Truma E2400), which, appropriately channelled, complements the original system, based on the classic Truma S5004.

Today the motorized vehicles represent, in all likelihood, the most immediate application scope of the slide-out technology, not only ultra-luxury products, but also vehicles that, featuring smaller external and internal sizes, may greatly benefit from the additional spaces one or more extensible provide.
Frankia’s challenge has now been taken up by Adria with the brand new Compact SLS, the superstar of the last Caravan Salon Düsseldorf. A compact low profile, as the naming points out, less than six meters long, which is aimed at the couples, designed to be agile and easy to drive (212 cm in width) but capable of becoming, during stops, a more comfortable camper, thanks to the rear slide-out that, placed in the rear part of the vehicle, above the classic garage locker, creates, by protruding 70 cm, the space needed for two twin beds to be created. A vehicle, then, that constitutes a sort of synthesis between the well-known and appreciated Compact SP and SL, with the bulk of the first during travels, and the convenience of the second once parked, which uses an electrical up-down system, the brand new Euro Slide, developed by Opp XL and now produced and marketed by american specialist Lippert Components. More agile than the one previously proposed by Frankia, the new Adria Compact SLS slide-out chooses to minimize the moving components, by featuring no double wall, but ensuring anyway an excellent aesthetic result thanks to the accurate combination between the frame and the extendable portion, well emphasized by a specific graphics and an extremely reduced external profile, quite similar to the frame of a normal service door, without overlapping portions. In the upper portion, we find the classic automatic-unfolding veranda (contextual to the slide-out coming out), while, the up-down system uses an electric mechanism with four synchronized engines operating on endless screws. A very well integrated slide-out, then, with rounded corners, particularly thin size, which combining design and precise movements, promises to blaze new trails, by marrying widely tested and tried technologies with an automotive design able to easily match to even sophisticated products of strictly European taste.

Resulting from a collaboration between the Erwin Hymer Group, AL-KO and the German magazine Promobil, the Hymer mockups propose what could be a slide out application on one of the vehicles produced the prestigious German maison. A contest launched last January, invited the readers to virtually configure their vehicle by using an extensible and combining layout and functionality based on standardized modules: after a careful selection, the German house has chosen the Düsseldorf Caravan Salon to present the two vehicles capable of getting consensus (out of a total of 340 different proposals), with a side version aimed at increasing the space available for a classic dinette of 65 cm, actually transforming it from a 4-seats into a 6-seats living room, and into a rear one, conceptually similar to that used on the Adria Compact SLS but featuring a central double bed that, with retracted slide-out, knee folds up and turns into a smart sofa. Such a solution was already used in late Nineties by Frankia for some VarioSpace models, in particular on the compact IN 600 VS overcab, and it shows, even several years later, its unquestionable validity. The slide-out used by Hymer, in particular, has been developed in collaboration with AL-KO: with electric up-down movement, it does not use an endless screw mechanism while opting for a toothed wheel one which is better able, according to the Kotz factory engineers, to ensure movement precision and smoothness over the years. Another cornerstone of the project concerns the gaskets ability to ensure the best sealing between the various elements, thus eliminating unpleasant draughts or, worse, dirt or water ingress: the system, in fact, involves the presence of a double gasket, with a circumferential rubber hose which inflates creating a true hermetic closure to and from the outside.

For years, the anglo-saxon world has proved to be particularly receptive and absolutely at the forefront for what concerns the use and development of recreational vehicle complete with slide-out.
Eclectic manufacturer, able to range from pure campers and low profiles to special vehicles aimed at sport teams to arrive up to trailers, Moto-Trek, with its head- quarters in West Yorkshire, uses one (or even two) side slide-out on different models. The large Euro-Treka low profiles, in fact, choose the american Lippert’s In-Wall Slide-Out system to significantly increase the already ample spaces available guaranteed by an overall length of 870 cm. Mounted on Fiat Ducato or Peugeot Boxer with AL-KO AMC chassis and dual rear axis, they are low-profiles aimed to couples looking for maximum comfort and feature three different interior layouts.
Euro-Treka G offers a maxi front living with opposite double-sofa and central table, central services, and, in the rear part, cross double bed over the garage: the slide-out, located in the vehicle front (right side), is designed to increase the living space available. Euro-Trema IB proposes a L-shaped front living opposite to a maxi kitchen block, toilet with separate shower and rear central double bed: on this vehicle, the extensible hosts the entire kitchen block that, coming out, allows you to free up a considerable space in the living room and toward the driver’s cab. Even more interesting, symbolic and perhaps even more close to the popular picture of the extensible-equipped vehicles is the Euro-Treka QB, characterized by two slide-out: one along the right side, in the vehicle front part, is aimed at a maxi sofa of domestic type that, coming out, allows to increase the space available for the kitchen block, located on the opposite side, while the second, along the left-hand side, is aimed at the bedroom with cross central double bed, featuring a solution not too dissimilar from that used by Tabbert on Cellini HTD 750. Large and bulky vehicles, indeed. To those who want to travel using more compact vehicles, although featuring extra-space during stops, Moto-Trek proposes the X-Cite series: two models, X-Cite EB and X-Cite G, with a length of just 638 cm, always mounted on Ducato/Boxer but with a total mass within 3.5 tonnes, feature a useful front slide-out aimed at significantly increasing the living space, and maximizing the interior space and, with the G version, allowing the vehicle to attract a much wider and varied customers’ group thanks to four beds, the half of which is made available by the extra space the slide-out provide. Just like the large Euro-Treka, the X-Cite exploit the Lippert Components’ In-Wall system. Prices start from around £50,000 for compact models and from about 75,000 for the larger ones.

Even more emblematic are the IH Motor Homes products: specialized in the manufacture of high-end vans, this Knottingley manufacturer, in West Yorkshire, has in fact applied the side slide-out to the classic van set on Fiat Ducato. An exemplary implementation, with the extensible which externally uses the space of the traditional side door, becoming completely invisible when not extracted, characterizes, in fact the interesting N 630 SL, a pure camper set on L4H2 van, with a length of 636 cm and featuring a very British layout: maxi rear toilet, L-shaped kitchen block and, in the front part, an actual living room integrated with the driver’s cab, with the slide-out that, by offering a comfortable sofa within, allows you to free up the space just in front of the doorway, and at the same time, to offer the centimetres necessary to ensure that the sofa can easily become a cross central double bed, transforming a classic van into an actual small loft complete with everything you could ever want in a recreational vehicle.

A solution similar to the IH N 630 SL, although proposed at prototype level, has been shown at the NEC 2015 by Lippert Components: a van that enlarges only when needed, thanks to two extensibles (side and rear), hidden on travel by the traditional basic vehicle’s original doors, which are made of fiberglass, thus combining strength, space and robustness without impacting too much on weights, about 50 kg per unit. New solutions, sometimes innovative as those introduced for some years now by Danbury on the famous Doubleback, which testify how research, progress and new ideas can be formidable allies in the development of some new and innovative interior layouts. Because, all in all, on any vehicle, space is never enough, especially the smart and flexible one.