I have read with interest a number of the posts on conservatories. My partner and I are about to build a new
conservatory and I would be interested in any comments on our plans.

The conservatory will be at the rear of our house with the longest glazed side facing north-west. At right angles
to that is a short glazed wall facing south-west. There will also be a glazed external doorway facing south-east.
The other two sides are red brick, the short one being part of the external garden wall shared with our neighbour, and the other being the rear of our house which has double-glazed windows and french-doors giving access from our living room.

The glazed walls will have dwarf-walls, and the roof will be glazed with glass. We want to have a timber frame,
and have been advised that for maintenance purposes using alu-cladding on the roof frames is best. The floor will be tiled concrete standing on a hardcore base of re-used building rubble, to act as a heatstore along with the short south-west facing wall.

One point we are not sure about, is whether to use single or double-glazing? We do not intend to heat the
conservatory, and it will be thermally isolated from the house by means of the double-glazed french doors.
We are hoping that, given that the main aspect of the conservatory will be north-west facing, over-heating in
summer will not be an issue. We would like to use the conservatory for as long a period of the year as it is
possible to do so without heating it (we are in the south midlands), to benefit from solar gain in cooler periods
where possible, but also to protect the main house from undue heat-loss in cold periods, so that the conservatory acts as a thermal break. Would single- or double-glazing best provide for these?

We are also having trouble sourcing a supplier that doesn't use tropical hardwoods, or else charge astronomical
fees. Elsewhere we have put in new wood frame windows which are engineered, laminated certified softwoods -
is anybody building conservatories with this? Any suggestions welcome!

No point at all in insulating or double glazing if there's no heating, unless planning to make use of solar gain. If that's the case then a form that's generated by understanding how that will work, will be essential - for sure a standard conservatory as you describe will hardly work in that way, or only accidentally. It will overheat like most conservatories, freeze in winter and at odd moments may be comfortable. Like a stopped clock that's right twice a day! First thing, as StuartB says, is a tiled insulated roof, about half the walls likewise - and you'll still have a very light and airy room that could be used all year round, whether by heating or, with knowing design, by solar gain, without overheating.

No insulation in the floor?

Thanks for the comments everyone - very quick replies.

Just to clarify: we aren't expecting to be able to use the Conservatory in winter, since we aren't heating it, and with this aspect don't anticipate the solar gain would be great enough. And we do want the roof to be glazed because, as djh says, the living room is already fairly dark.

The issue about double-glazing, as I understand it, is:

- to protect heat-loss from the house in winter, is the use, and extra cost, of double-glazing worthwhile, given that the house is thermally isolated from the conservatory with the double-glazed doors and house windows? There will be an impact on the construction requirements of the frame, presumably, from needing to support the extra weight of glass, also adding to the cost.

- on marginal spring and autumn days we hope that solar gain might make it usable. I read somewhere that single-glazing is better for solar gain because it allows more light to pass through; but presumably the heat so gained is conducted back out faster than with double-glazing?

Re insulation, there seems little point if we single-glaze, but if we double-glaze we would insulate the walls and under the floor. Our main intention with the floor is, as a thermal mass, to help in moderating the temperature extremes. Any thoughts?