The open-plan layout conservatory
A design or plan solution to the problem of overheating in a conservatory is to look at opening up the conservatory to the home and letting some of that heat disperse around it. Given our love of daylight and the warmth of the sun, it seems crazy not to want the rest of your home to reap the benefits of a conservatory. Creating an opening in the wall between the two and making the conservatory an integral part of your living area changes many things, from the way you use the extra space to the regulations that apply and the impact they have. In fact, whether to separate your glazed addition with a door or to open it to the home is by far the biggest design question of all.
As we’ve already seen, even the highest standards of double-glazing fall dramatically short of what is required from insulation these days and an extension or conservatory with a glazed roof and mostly glazed walls is going to be far more sensitive to the outside temperature. In the UK, as in most temperate climates, we enjoy the possibility of a wide range of temperatures from well below freezing to well above 32 C, with record temperatures that wouldn’t be out of place in the Sahara Desert. When the sun hits the glass, magnifying its power, high temperatures of 30 C can arrive in April and extend to the end of October and even in the winter months it can exceed 20 C.
All of this means that an open-plan layout conservatory can benefit from the free heat of the sun and use it to centrally heat the air throughout your home, rather than build up inside the conservatory alone. In the cold, sunless days of winter, however, those long spells of icy winds and sub-zero temperatures will see your conservatory converted into a heat sink with a large unplugged hole in it. The warmth that your heating system is expensively creating to keep your home comfortable will be drained out through the opening to your glazed addition, leaving you struggling to keep the house warm and burning more energy to do so.
An insulating door or folding screen that allows you to close off the conservatory in cold weather and keep the heat in is a good idea and not only that: since 1985 it has been essential in exempting conservatories from the Building Regulations. Indeed without that insulating separation (which can be double-glazed itself) your conservatory needs to be controlled and approved under the Building Regulations. In the legislators’ eyes, it is no longer an extension to your home like any other extension and this means that the stringent standards of thermal insulation that apply to the building of an extension relate to it. And sadly, that is often enough to kill the open-plan idea stone dead. Why? Because it simply isn’t possible to meet those elemental standards of insulation for roofs using glass or polycarbonate. A more holistic approach is needed – one that looks at the home as a whole as it is at the moment and assesses how much heat is lost through it and then looks at the proposed home with the open-plan conservatory added on and says “Is it really that bad?”
The answer to that question may determine whether approval is given for an open-plan design or whether it must be separated and exempt from building regulations. To a large extent it is down to your local authority Building Control Officer and whether he or she will consider it to be reasonable.