This week in the Examiner, Kieran McCarthy of KMC Homes provides advice on how to reduce heat loss in your conservatory.

Q. We built a conservatory about 15 years ago which is sucking the heat out of our house. We had the roof insulated and plastered and lightweight tiles put on so it looks like a proper roof from outside, but it hasn’t made much difference.

Are there any solutions other than ripping down and building a proper extension? I want to keep the same footprint but really would like to open out the kitchen into this room as our kitchen is small.

A. Adding a conservatory to the back (or side) of our house added a room for family gatherings and general leisure activities. Bliss! Or was it?

Unfortunately, during the summer these glasshouses became like Scandinavian saunas, while in winter, they were like igloos. So, where did it all go wrong and how do we rethink this social hub and redesign it to suit all seasons?

The issue with conservatories was that while they catered for a vital social and leisure space in our homes, building design had not yet caught up with this new glazed extravagance. The ground slab was often just a concrete slab laid on a thin layer of insulation (if at all), and all laid in one day so no effort was made to prevent coldness from entering the slab from the edges and indeed much of the cold in the ground wasn’t kept at bay at all.

The walls and the roof were made from glass, usually single-glazed. The issue here is that single-glazed glass will allow nearly all the heat to escape in winter and provide no defence against solar gain when the sun shines in summer. This may be why you are generally losing heat through this room for much of the year. So, what can be done?

insulating and clad the roof (internally) and, though not ideal, will help a lot with the seasonal use of this room and, as it is essentially outside of the thermal envelope of their main house, they don’t lose heat from the house to the conservatory in winter.

In your case, it appears this is not possible. To remedy this, I feel you have two choices: Either install a double-glazed sliding door between the house on the conservatory or, if the budget allows, knock and rebuild the entire extension. If you were building a new sunroom, I would advise as follows: Get an engineer to draw up plans for an insulated concrete slab. Now you will be fitting 150mm of new rigid insulation beneath the floor with 150mm of concrete on top. You will fit 25mm of insulation at the edges of the concrete slab to ensure the slab doesn’t get cold at the edges

View full article in The Examiner here.




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