Conservatory: lovely concept but far too hot in summer, too cold in winter. Terrible thermal performance is the number one reason to get rid of it, that’s what it’s trying to tell you! But take care not to replace it with an extension that is glazed to the extent that the same problems might persist.
Designing a new extension to replace a conservatory is a brief I’m commonly presented with. The main reason cited for replacing it is always poor thermal performance, don’t get me wrong – conservatories have their place but they aren’t very functional for year round family living and if yours is a dumping ground for toys and garden paraphernalia, fear not – there are others out there just like you.
That said, there are some huge advantages in terms of light that come from a fully glazed room. And in replacing a conservatory it’s often the case that you’ll want to go for as much glass as you can, which could in turn perpetuate the same conditions. Fortunately, the Building Regulations have some criteria to help you avoid this in terms of amount of glazing that is permitted before you reach a tipping point. After which you’re required to mitigate your excess glass by “over insulating” other components to compensate, although this is more in relation to heat loss than solar gains.
There are lots of options including triple glazing and solar control coatings to help improve the performance of your glazing and the orientation of your building will be a key factor too. The angle of the sun comes into play somewhat in the UK where it’s low and weak in the winter (desirable) but high and hot in the summer (problematic). If your main elevation is south or west facing, you’ll need to consider the design quite carefully to avoid overheating in the summer months. Solar shading in the form of a roof overhang or vertical fin might be an appropriate solution.
Rarely do people say “I want to replace my conservatory becayse I hate looking at my garden”. But it’s worth considering, do you want to look out on all of your garden or just the best bits?
Frame a view of something worthwhile, mask out the ugly bits. Yes, the apple blossom is nice but do you want to look out at your knickers on the washing line when you’re sat on the sofa… when your friends have popped round to admire your lovely new extension? Maybe not.
It’s also worth considering that floor to ceiling glass can play havoc with your furniture layout, see also Is Open Plan Always The Answer? where it turns out walls have their place.