Panoramic glazing with no visible uprights

It is VEPA glazing: glass walls that enclose projecting balconies, loggias and porches recessed into the building, and that can be opened and removed. They are defined by Article 6 of the Italian Building Code, Presidential Decree 380/2001, which under certain conditions puts them within permit-free building work.

The conditions are precise: completely transparent, with no masonry parts, in toughened or laminated glass, removable, with a profile that does not alter the lines of the building. The heaviest condition is the last one: they must not create a permanently enclosed space, so no new volume and no change of use. If the space becomes a room to all intents and purposes, it is no longer VEPA glazing and you are into different paperwork.

The first is also the most misunderstood: they are single glazed, not double glazed. They stop wind, rain and dust, but they do not insulate like a window, and condensation forms on cold glass. Anyone buying them expecting an extra room will be disappointed.

The second is the seal: the gaskets between one pane and the next are effective, but they are not hermetic. With driving rain and strong wind a few drops can get through the joints. Then there is the sun: a glass wall facing south, with no shading, heats up a good deal in summer.

Far less than a window, far more than nothing. The real step change is the wind: stopping moving air is what changes the perceived temperature, and on a day of north wind the difference between an open and an enclosed porch is felt immediately.

In numbers, though, the glass is single and toughened, with no cavity and no gas: the thermal transmittance is a long way from low-emissivity double glazing. The space stays warmer than outside and sheltered, but it is not an insulated room and should not be treated as one.

It depends on how the work is classified, not on the product. The fact that VEPA glazing falls under permit-free building work does not in itself rule out the relief: for permit-free works the Italian Revenue Agency asks for a statutory declaration with the start date of the works and a statement that the work is among those eligible. What counts is whether the work amounts to extraordinary maintenance on the property.

The window ecobonus is a different matter: it presupposes work on the envelope of a heated space with an improvement in thermal transmittance, and a balcony or porch enclosed with VEPA glazing is normally not a heated space, so that route does not hold. Before signing, have your case assessed by an accountant or a surveyor: on panoramic glazing the classification is the delicate part.

From inside with roller blinds or venetian blinds fixed to the lintel, from outside with an awning or a pergola that intercepts the sun before it hits the glass. The second solution is more effective, because you stop the heat outside instead of finding it inside.

One thing to watch: the rules on VEPA glazing require it to be completely transparent. Frosted or screen-printed glass and opaque films can make that requirement fail. If you need privacy, it is better to solve it with removable shading than with the glass.

With radiant heat, not by heating the air. Infrared lamps or outdoor radiant heaters warm people and surfaces and work even in an uninsulated space, where a fan heater works for nothing because the heat goes out through the single glazing.

A practical warning: taking the house heating system out there is what must not be done. A balcony or porch permanently heated becomes habitable volume to all intents and purposes, and that is exactly the condition the VEPA rules do not allow.

The glass with water and a neutral detergent and a soft cloth, no abrasives and no scrapers. In stacking systems the panes rotate on themselves, so you can clean the outer face while staying inside.

The maintenance that really counts, though, is another: the bottom track. Sand, leaves and dust settle there and are the number one cause of panes that run badly. Go over it with the vacuum cleaner now and then and brush the vertical gaskets. A couple of times a year a spray lubricant on the carriages keeps the system smooth.

The square metre is a misleading measure here. Two enclosures of the same area can cost very different amounts: a long, low one needs more panes and more metres of track than a tall, narrow one, and above a certain size of single pane the glass thickness has to go up, with weight and hardware going up accordingly.

The price is driven by the number of panes, thickness and type of glass, the direction of opening, the length of the tracks and the preparation of the floor and the lintel. That is why we come and measure first: after the site visit you get the price written item by item, and it does not change.

In sliding systems the panes run on several parallel tracks and overlap one behind the other. No space is needed at the sides, but the opening reaches at most half or two thirds of the span, because part of it always stays covered.

In stacking systems the panes run on a single track, reach the end, rotate ninety degrees and gather into a pack against the wall. The opening is left almost entirely clear, but you need a stretch of wall or a free space to park the pack. If you really want the porch open in summer, that is the route.

Yes, and it is the most common case. The rules expressly mention balconies projecting from the body of the building and recessed loggias: the glazing starts from the existing balustrade and closes the upper part, or comes down to floor level where the balustrade is glass or is kept.

In a block of flats there are two extra steps before ordering: the building's own rules and the architectural character of the facade. If the building already has other enclosures of the same kind the route is easier; if you are the first it is worth going through the owners' meeting. And if there is a landscape restriction, authorisation is needed, which does happen along the coast.