"We build a house”   7-8/2003
 
"Winter gardens, which are sometimes also called  orangery, bring more variety and color into the house. If they possess an exit into the garden, they form the natural connection between house and nature. "

Winter gardens are known for centuries, first as the free-standing orangery which were established for palaces and mansions; tropical plants were cultivated here or kept in the winter. Over the time they also appeared in middle-class houses in the form of glass verandas or additions. They functioned as a ‘green living room‘. Winter gardens are often an integral part of many house projects. The solutions look very different: from the big glass bay window up to extra additions with a separate entrance from the living room. Winter gardens can also fulfill different purposes. [...]”

A winter garden, which is planned as an addition, can fulfill the function of a thermal buffer. In the summer, it takes in excessive direct sunlight and prevents therefore high temperatures in the interior. In the winter, walls and floors store the warmth and pass it on into the building.

Therefore, a smartly planned and realized winter garden can be an element to decrease  energy costs. 

Different kinds of winter gardens
 
The winter garden can be planned  separately or also a shared heated area. Depending on the prevailing temperature, distinguish between cold or warm winter gardens.
 
A winter garden without heating is made of a separate room, which is raised on the outer wall of the building. In a lot of cases, this is a closed terrace. The advantage of this solution is the prevention of heat loss.
 

In a so-called „cold winter garden” the temperature is 5‒15 °C and never falls under zero. Despite isolated foundations and the right thermal insulation of the dividing walls it would be an asset if the winter garden was connected to the central heating or disposes of an electric heater with low output. Such a winter garden indeed cannot be used in the winter to the full extent, but some house plants and also garden plants, which must be taken out of the ground in the winter, find here excellent conditions for spending the winter. There are also plant groups which can be grown very well in cold winter gardens. These are among others: acacia, Monkey Puzzle, datura, citrus fruits, date palm, gum tree, fuchsia, yucca palm, myrtle, oleander, Washingtonia.
 
A heated winter garden, the so-called „warm winter garden”, normally increases the space of living in the building and can be used all the year round. If it forms a separate room, this must be completely heated. In such winter gardens the temperature is 15‒25 °C and never falls under 10 °C. Here more sensitive plants can kept like Anthurium, Dracaena, Pygmy date palm, gardenia, Hoya, Codiaeum, Passion fruit, Callisia.

Location of the winter garden
 
An important factor, which is decisive, is the direct sunlight that means the orientation towards the different cardinal directions. 

Winter garden towards the East
 
The intense direct sunlight up until the afternoon hours, requires the installation of  sun protection and ventilation. Plants are very comfortable here and the winter garden provides, in winter, a thermal insulation for the building
 
Winter garden towards the West
 
The strong direct sunlight in the afternoon hours, requires in the summer, also sun protection and ventilation. From spring to fall it is an excellent place for plant growing. Just like the winter garden with orientation towards the East ,it guarantees thermal insulation for the building.   

Winter garden towards the South
 
Strong direct sun light throughout the whole day, also during winter time. It requires extremely effective ventilation, sun protection is necessary and panes protecting against solar radiation are recommended. In such a winter garden plants also are comfortable and the room guarantees thermal insulation for the building in the winter.

Winter garden towards the North 

In this case, a sun protection is not necessary, because over the whole day, also in the summer, very little direct sunlight is present. It is a good thermal insulation for the neighboring rooms, but is suited only little for plant growing. [...]

Construction
 
In the best case. the winter garden is already planned in the house project. However, it is also possible to build it on an already existing object. However, some requirements for the construction must be fulfilled.
 
The frame of the winter garden must be joined firmly and break-proof with the building walls. [...] The whole construction and all connections must be sealed completely. It is to be pointed out the construction elements don’t have to be straight, but can also be bent, what opens the variants of possibilities for the architect.
 
It is also possible to build the winter garden on an already existing terrace, under the condition that its foundation can carry such an additional load. [...]
 
Winter gardens are made out of aluminum, steel, PCV or wood. From these materials only wood allows constructions with spans up to 7 m. [...]
 
An interesting solution is a wooden skeleton to which aluminum guidances are mounted. Raising the lower elements results that only the roofing stays and through this the winter garden is integrated into the garden. The shifting of the roof elements allows opening the roof completely and at the same time guarantees a windbreak. [...]