Growing climbers and other plants in conservatories is often the only option in our modern world where the conservatory is really a further extension of the house and designed and usually built as such.
Often there is little or no consideration given to the basic factors affecting plant health and growth. Commercial nursery structures are designed with solely these factors in mind and I often think that there is room in the huge conservatory construction market, for a synergy of the ideas of domestic comfort and factors affecting basic plant health; Light, ventilation and temperature control.

I do know that several manufacturers will build a bespoke conservatory with all the features you desire but they are rarely standard considerations in the design and having seen many, many contempory conservatories which are constructed as extensions to houses they present a host of problems which make a huge difference towards plant health and vigor.

I suppose I shouldn't be surprised as a 2002 industry survey indicated that 47% of all conservatories built in the UK were being used as extra living rooms and 24% had no plants in them at all.
Using the room for a living and eating space of course is prerequisite in this age but by addressing the design problems the serious gardener can drastically increase the health and vigor of the plants he grows and reduce the problem of pests which usually become chronic after a few years.

I know many customers who have given up growing plants inside their conservatories because of the pest problems which were so bad. A visit to Wisley, Kew or the Eden Project to name but a few will show that without a flexible approach and employing a range of disciplines, that these institutions can suffer just as badly from pests and disease problems as the smallest conservatory in the average house.

Dealing with the factor of light is important and it is closely linked to the second factor of temperature. More often or not the conservatory is built where it is feasible and not with growing plants in mind and in many cases comes with the house you buy.
Such was the case of the house I lived in for some years in SW London which had a conservatory which was freezing in winter and boiling in summer. The structure was a big lean-to living space added to the back of the house and facing the garden and it had a Southerly aspect and contained a large breakfast room and kitchen. It had no roof vents and only doors both into the main house and several adjoining doors which could be opened into the garden making this the main opening.

In summer when the sun hit the roof the conservatory got extremely hot and by midday it was uncomfortable and with no roof vents the temperature could rise way up towards the high 40s. Lack of ventilation and then lack of shading is the most common problem with conservatories and affects plant growth.

Designs are now getting better and many well known companies are now including roof vents in their designs. However a southerly aspect will still generate huge heat inside especially if double glazing is fitted throughout as is more often or not the standard now.

The answer is shading which although is an expensive item, it is crucial if you are keen to regulate your conservatory and have a serious passion for growing plants. Both the temperature and sunlight can be automatically controlled in your conservatory .
Roof vents in commercial glasshouses are controlled by expensive microprocessors and electric motors but in the home situation a hydraulic piston can be fitted which opens and closes the window/vent as the temperature rises and falls. These items are extremely cheap in real terms and each one is easily fitted and does not compromise the security locks etc. Controls for shading are more problematic with small motors connected to a thermostat and electronic eye being the only option and not cheap but worth while if possible especially if you have the misfortune to be in a suntrap. Also a good sensible and cost effective option is static shading or a roll of material that can be pulled down on the hottest days.

I always used to think that the greater the heat and humidity the better the plants would grow. Alas this is not the case and just a few problems that are caused by excessive temperatures and sunlight are; serious pest problems, reduction in growth rate, lowering of resistance to diseases and physiological problems such as bud drop and scorching.

Red spider mite and mealy bug are two serious pest problems that are greatly increased by high temperatures and/or temperature fluctuations and high humidity. Ventilation and the good circulation of air is a major factor in reducing disease and fungal problems and commercial glasshouses are designed for maximum ventilation.

In winter temperature and ventilation are always a problem especially for tropical plants and conservatories where higher temperatures are needed. I have found that keeping high temperatures is less important in winter than you might think and that by reducing temperatures and resting plants you will end up with a stronger flowering and healthier plant.
Heating will usually be part of the houses central heating system which is fine and will help exclude frost. If not a small portable heater is ideal but usually expensive. For serious plants folk a more critical control of temperature can best be provided by under floor heating which is now employed by commercial nurseries on a grand scale. They are superior to air heaters/blowers and far more economical.

Although it is not possible to cover these critical factors in great depth it is advisable to at least see what your ventilation, shading and heating options are and how they can be improved with the minimum impact and fuss and of course cost. If possible a sunken or raised soil bed is far preferable to growing plants in pots because of the dynamics of the soil regarding nutrients for example and the superior conditions it offers to your plants root systems.