The conservatory – cope with winter the comfier way

Say ‘conservatory’ and words like lovely and beautiful come to mind. Dive a little deeper into the etymology, however, and go back a few centuries and it all becomes clear. It’s not by chance that people first started building conservatories at a time when the era of colonialism peaked, in the 18th and 19th centuries. Back then, the high and mighty took every opportunity to showcase the exotic flora they had discovered in overseas territories on returning to their European homelands. What they soon realised, however, was that the cooler and darker climate they had grown up in was far from what their prized plant life actually preferred. The solution: a heatable room with large windows, bathed in sunlight or even a room made of windows alone! The conservatory had come into being.

Fast forward to now, however, and far from being luxury add-ons, modern conservatories are useful features and more than worth their while:

• They enhance the value of your property.

• They increase the amount of usable or living space.

• They regulate the temperature and can even help save energy during colder seasons.

• They let more light in.

• They provide shelter and warmth that let plants withstand winter.

Sounds good? If you’re keen to explore the idea of a conservatory for yourself, you’re in the right place. Coming up: the lowdown on their forms of use, construction methods, materials and building codes and costs.

Which conservatory should I choose?

As a general rule, people usually categorise conservatories into the following three categories: residential conservatories, temperate conservatories and unheated conservatories.

Residential conservatories are heated and insulated and since they are usable year round as part of the interior living space, they are defined as an extension of the house under building law. Accordingly, the same thermal insulation regulations as for normal living space apply, imposing specific glazing and waterproofing requirements, which makes constructing such conservatories slightly costlier. You will also have to apply for a building permit, but more on that in the section on “Legal regulations”.

Temperate conservatories, meanwhile, can be moderately heated, although the exact extent varies depending on location. But on sunnier days in winter, you may even find your conservatory gets toasty warm enough without any extra heating help. A great go-to if you want your plants to see out winter unscathed, they can also be very appealing areas of covered seating in the warmer seasons. And limited heating capacity here means no additional thermal insulation requirements need be met.

Finally, unheated conservatories are only warmed by the sun, as the name suggests. With that in mind, although almost always outside the normal living space in colder seasons, they can offer some respite as a repository of plants over winter or a visually appealing entrance feature. While the lack of heating does give these basic conservatories a humid indoor climate and render them more prone to mould, choosing the right material (e.g. aluminium profile) can solve this issue. Such ultra-simple conservatories are far cheaper to build and maintain. Another plus is that far fewer building regulations apply, underlining how easy they are to set up in place.

How best to configure your conservatory?

Well, needless to say, designing and conceiving your dream conservatory is the most fun part of the process! What visuals appeal to you? Building elaborately, with turrets and bells and whistles or simple and minimalist? Your imagination is more or less the only limit... but how about when it comes to tangibly applying all that for real? Well unless you put such conservatories together for a living, you’re going to want professional help. Here’s one great example: Karl Blaser AG – expert and experienced when it comes to conservatories, roofing and glazing.

Remember, the decisions you make today will impact on how happy you are with your conservatory going forward. Your choice of material, glazing and shading features are key criteria that will ultimately dictate how much you enjoy the space, its technical properties and how much maintenance will be needed. So plan cleverly - and carefully consider the following questions:

What materials do you wish to use for the conservatory framework?

Whatever building material you use, the properties and their respective advantages and downsides will vary. Of course, you can also use a range of different materials in combination.

Plastic

• Affordable

• Partially recyclable

• Not very durable

• Low-maintenance

• Caution: Low heat resistance - to reduce thermal expansion, only light colours should be used.

Wood

• Cheaper than metal

• Environmentally friendly

• A great insulator

• Caution: Maintenance-intensive: Unless wood is treated professionally and regularly, rot and mould can occur.

Aluminium

• Costlier than non-metal alternatives

• Very stable and weather-resistant

• Low-maintenance

• Ultra-sturdy

• Caution: Metals are not very environmentally friendly to produce. Mining them is very labour-intensive and processing them consumes vast amounts of energy.

Steel

• Costlier than non-metal alternatives

• Very hardwearing and sturdy

• Poor insulator and as such, unsuitable for residential conservatories

• Caution: Steel must be specially treated to eliminate the risk of rusting.

How best to glaze your conservatory?

It goes without saying that the more glass you use, the closer you feel to the outdoors. And that’s precisely why getting the glazing decision right is crucial. To a large extent, your choice of glazing solution will also dictate the room temperature in the conservatory. With keeping your conservatory warm in winter and cool in summer the main issue, we recommend double- or even triple-glazed thermal insulation glass.

Thermal insulation glass: Nowadays, most conventional double- or triple-glazed windows are fitted with thermal insulation glass. And the stand-out feature of this product is the coating applied, to reduce the amount of heat radiation absorbed and dissipated. The coating comprises precious metal particles that reflect thermal radiation. The fact that it is applied to the outside of the inner pane within a multiple glazed configuration eliminates the risk of damage due to cleaning or weathering.

Double glazing: In insulation terms, it outperforms single-glazed windows, which is why such glazing is now standard in most conservatories (except those unheated). This is done by juxtaposing two panes of glass, double-glazed in parallel and separated by a layer of inert gas. The gas phase between the panes minimises heat transfer from the outer to the inner pane and vice versa. A set-up like this paves the way to keep the conservatory warm in winter, since heat generated elsewhere in the home will find it hard to escape from a double-glazed conservatory. In summer, conversely, the opposite applies, as the heat comes from outside and can only penetrate minimally.

Triple glazing: The same principle applies here as in double glazing, but with three panes instead of two. The resulting configuration, which includes dual layers of inert gas, can achieve insulation performance up to six times higher than double glazing. But the need for a more complex design makes the panes involved far heavier and costlier.

Laminated safety glass: Laminated safety glass should be your first choice when constructing the conservatory roof or any other overhead glazing, given its improved ability to withstand the extreme stresses of snow, rain and gravity. Additional breakage protection comes courtesy of a tough elastic film.

How can you protect yourself from the sun in your conservatory?

Even a thermal-glazed conservatory can heat up unless it’s properly shaded and you won’t want to be dazzled or sunburnt while using it either. The answer? Channel your James Bond and get shadowing. Here’s a hat-trick of helpful tips:

1. Indoor shading systems: Folding blinds, curtains and roller blinds are easy to install within your conservatory interior and also represent the most economical shading solution. Warning! There is a risk of heat building up between the glass and the shading medium, which will result in additional solar heat dissipated throughout the conservatory.

2. Outdoor shading systems: Blinds installed on the outside of your conservatory can provide shade and cool down the interior temperature considerably, while preventing excessive air consumption. Warning! External blinds are exposed to the elements and thus require regular cleaning.

3. Solar control glass: Solar control glass filters high-energy light radiation to reduce the heating effect of solar radiation, albeit without any glare protection. However, it can be combined with thermal insulation glazing or triple glazing. Warning! Solar control glass reduces the warming potential of the sun, even in winter. It’s also a very expensive choice, which may cost up to 50% more.

How will you heat your conservatory?

As we mentioned earlier, your conservatory of choice can be heated in various ways. The bottom line, however, is that if it is part of your year-round living space, heating it appropriately is a non-negotiable. This applies to so-called residential conservatories, the construction of which must therefore comply with thermal insulation regulations applicable to conventional rooms. Within Switzerland, however, the fine details of these regulations vary depending on your canton of residence. So make sure you are fully aware of what you are allowed (and obliged) to do.

If you go for a temperate conservatory instead, your construction may be exempt from the thermal insulation regulations mentioned, the caveat being that it may only be heated to a legally specified temperature (which varies from region to region). As a general rule, we recommend opting for a heat pump with underfloor heating for your conservatory, which is arguably the best choice from an ecological perspective. Air-air heat pumps are particularly ideal for a conservatory setting, although electric heaters could also be installed.Beware! Before, you were allowed to heat up cold conservatories with an electric radiant heater, but such non-renewable heating systems are now no longer permitted outdoors.

Does the conservatory require special ventilation?

Regularly ventilating your conservatory is a must, without which you have to contend with an unpleasant build-up of air and a higher risk of mould in summer. But given the volatile nature of sunlight and cloud cover, an electronically controlled ventilation system responsive to current weather conditions is recommended. Cheaper mechanical ventilation alternatives include windows, hinged or sliding doors and ventilation flaps.

Your conservatory – permits and regulations

Whether or not you are allowed to build a conservatory at all, and - if so - how big it can be, is mainly determined by two regulations.

Firstly, the floor-area ratio is one decisive criterion that dictates what area of your property may be developed into living space. And if all that area is already developed, you are normally then restricted to an unheated conservatory only, as it does not count as living space. However, this also varies depending on the municipality, so always clarify this in advance. Conversely, you must also observe the cantonal distance regulations, which regulate the interval distance between your building and that of your neighbours. Caution! Just as for thermal insulation regulations, building law is also regulated on a cantonal level. Plus, special regulations for conservatories may even apply in your canton of residence. To avoid any doubt, find out exactly what you need to know at the building authority in your municipality.

How much should I expect to pay for a conservatory?

What a conservatory costs varies just as much as the myriad construction options available, starting with the most basic unheated conservatory at around 30,000 CHF up to a luxury residential conservatory, if money is no object. Temperate conservatories are slightly pricier, due to the additional heating system involved. Residential conservatories, meanwhile, are far more expensive, given the need to meet completely different requirements and regulations. Here are some rough ballpark figures assuming a 15 square metre conservatory as follows:

• An unheated conservatory will cost an average of around 30,000 - 40,000 CHF.

• A temperate conservatory will cost an average of around 50,000 - 60,000 CHF.

• A residential conservatory will cost an average of around 80,000 - 100,000 CHF.

How you opt to glaze the conservatory and the openings and equipment you include also have a major impact on the end price.