In his imagination!

that sounds reasonable, but whilst walking round the village at the weekend I did note that many local's had dg windows, roller shutters and an internal wooden shutter. seems belt and braces, but might work

would assume that your dg is ok but the bigger the gap the bigger the saving and it is cheaper to make dg glass with a thin gap. thats why some people have invested in triple glazing

we all expect to have better insulation in the UK but when we come out here for the sun sea and sangria we don't expect to have to dress up in an overcoat indoors or to have blanket to keep warm.

and someone here will bring back that old arguement that I don't deserve to get Winter Fuel Allowance.

Thats what I thought .... but having said that sealing the outside and inside wall must have an effect, even if it's only to combat dampness

Like you our house is designed to the very latest Spanish Building Regs with one or two additions from UK to further improve things. For instance we have DPC's everywhere and the columns are insulated from the walls to ensure no cold bridges. the orientation is N/S for the long axis to avoid some of the summer heat. BUT we have that northern European love of large double glazed siding window forming almost the whole of the west wall so we loose there in winter and in summer when the sun is low in the west at sunset we get large heat gain! However the house is normally cool which means that winter can mean it is warmer on the south terrace in the sun for lunch.

Good insulation works both ways warmer in Winter but cooler Summer.

yes, I am more than aware of that - but if you take a dinghy out to sea it is waterproof, cut holes in it and you will let water in.
the same principle applies to buildings - no matter how well you insulate with double/treble thickness etc etc as soon as you cut a hole in it you are stuffed.

never wondered why some houses have little small windows whilst the funloving Brits go round fitting huge sliding windows etc.??

Yes but it's much nicer to have all that light streaming in and in the summer to have air flowing through the house.

We have about 35m2 of glass in our living area and it leaks heat like your holed dinghy!

Still I wouldn't change it and the year's heating bills are still less than UK council tax!

About the same here!

We live in an old 1960's single story house, we have a very large roof terrace that covers our kitchen, shower room and dining room...
Unfortunately the people who put the terrace up there didn't see fit to spend the money on insulating it at all, consequently it makes these rooms like a hot house in summer and like a fridge in the winter, it also causes a condensation problem on the ceiling of the shower room where each of the concrete beams are.
It's my intention at some point this year to have the tiles removed and some good insulation put down, then I'll have it re-tiled.
I really cannot understand why the last occupants cut corners in such a way just to save a relatively small sum of money.

Another job to get around to some time is the single glazed windows, also a single glazed glass door and the other door which is metal, they have got to be the source of the biggest heat loss here!

And yes we do need the winter fuel allowence...it's colder in here than it ever was in our English house!

Ref how much glass: If we're talking about the actual living room rather than various living areas, I'd say in our 150ish year old former mill the windows and door combine to provide... maybe 1.5 sq m of glass !!!!!!

As to why some properties have such poor weather proofing, it's my belief that in cases such as ours the person converting wanted a holiday home and nothing more, therefore wasn't unduly worried about keeping the cold out on a long-term basis, nor had they yet really 'got' the idea of keeping the sun/heat out either!

I think that's very true. Most of the thousands of small houses built on the costas over the last 30 years were only designed to be used as holiday homes.

You can often see that in the inadequate size of the kitchens and power supplies!

An easier option would be to lay polystyrene slab insulation straight on to the existing roof then lay slabs or shingle on that. As long as water can drain through to the existing roof there should be no problem.

It's not a former mill and not 150 years old, it was built in the mid 60's as a finca and divided into two properties in the 90's as a permanent residence, not as a holiday home.

There were quite a few corner cutting things done as the former owners liked to do things on the cheap, we have in fact spent the last four years and quite a large amount of money redoing the jobs that they skimped on.

As the former owners lived here for quite a number of years... I don't understand why they didn't do things well in the first place, as doing so would have added tremendously to their comfort levels.

I'm not a fan of that kind of thing!
As we are in a quake zone (I often feel the earth move) there is often some movement in the building, it's better to be able to access the original roof structure easily in case of a leak.

Good point.
The 'upside down' design is not unusual in the UK. I didn't give a thought about quakes.