When we designed the kitchen/diner extension we wanted to ensure we captured 'good' warmth from the sun, or 'solar gain', whilst avoiding 'bad' solar gain. Capturing the good at this time of the year is working - over the past few days the extension has been warmed by sunlight that has streamed in via the extensive amounts of glazing to such an extent that the heating in this room has switched off. With large windows on the east and south sides of the extension, the low March sun reaches deep into the room, heating up the limestone floor and other surfaces. The warm surfaces then radiate the free warmth into the room.
All this is great, but what we don't want to experience is the typical conservatory greenhouse effect that blights too many UK homes. As a relatively inexpensive way of gaining extra living space many homeowners add glazed conservatories onto their homes, often on south or west facing walls. This means that a room which is pleasant in the Spring and Autumn gets the full force of the summer sun, becomes too hot to use during the summer months and transfers the excess heat into the rest of the house compounding the problem.
To avoid this from happening with our extension we've incorporated a few key design elements. Unlike a conservatory the roof isn't glazed, so only sunlight at a low angle can penetrate deep into the room, e.g. Spring and Autumn sun. The roof has generous overhangs so that during the hottest times of the day in the summer when the sun is almost overhead, little direct sunlight will enter the room. Deciduous trees on the south and west boundaries of our garden provide the additional solar control, with the bare trees allowing in Spring sunlight but once they are in full leaf they will soak up the unwanted heat of summer.
Only time will tell if what we have designed will work fully as intended, assuming we get a hot summer of course. I wonder which is least likely...
