I certainly can't speak for "all clients" but we are going through that process right now. We bought a block of land intending to knockdown rebuild. Being a fan of eco and green designs from my time living in Europe, I spent time hunting for the right person to design and build the new home to be functional, beautiful and highly energy efficient. We wanted the energy efficiency to form the bedrock for the rest of the design and build, but did not (as many responders have pointed out) that to compromise the flow or aspects of the design we felt to be important. To be honest, it was harder than you would think. A lot of people we approached seemed to assume that energy efficient design meant a "designer label" approach and wanted to charge a massive fee for the privilege. This was very disappointing. I don't think that good, eco design should be restricted to those with money to burn. Affordability certainly limited our choices. Although it starts with a good design that makes the most of the site and the client's wishes, it should not stop there. There is a wealth of information out there pointing to the places in every building where heat / cool air is lost and where a building becomes inefficient. It takes a knowledge of insulation, suitable materials and building techniques to ensure that the resulting house actually does what it said it would. I don't think that gap has been closed as effectively as people think. BASIX is a basic or minimum standard, after all (and perhaps this is not well understood by us as clients and consumers - it has been a hard 18 month journey to understand the complexity of the issues around eco design). Again, affordability becomes a major factor because it is still seen as heavily "bespoke" rather than a natural evolution of the way we build for the future. Finally (and it's worth saying), the information around this topic is not easy to find. Being a meticulous researcher, it still took me in depth searching over many weeks and months to find the right people and the right information. I suspect many people just too time poor and don't have the time or energy to do this. As a consumer, I would hope that the companies I deal with understand these principals as a bare minimum but suspect that not everyone (on client or trade side) is yet seeing this as a basic standard. Although it was integral to our project, I don't think energy efficient principals is at the top of the list for everyone - if my interactions with the trade side were any judge of the industry. It's an interesting question, very pertinent. Thank you for asking it; I'd be curious to know why you wanted to ask?

In the UK for example they use a lot of roof windows but these are usually double or triple glazed, super insulated walls and roof's, etc. Mainly due to lacking good natural light they need these large glazed area's. They're thermal efficiency standards are a bit higher than ours as well. In Sydney we have cool winter's but certainly nothing like the UK. We have almost the opposite issue of heat. Therefore roof windows are not really a great idea. I'd almost say heating a house in winter is the least of your worries, for a couple months anyway. Cooling it for summer however... Double glazing is still not on everyones list of improving their homes. Sparkles and glitter is but not many care about the efficiency of their home.... If you add large windows or doors specific double glazing as a minimum. Use thermally broken aluminium frames or timber. PVC is slowly becoming popular. If you can insulate walls, floors and ceilings, replace existing windows and doors with double glazed this will go a long way to improving the home. An air-conditioned home or one that uses just ceiling fans can be very efficient once insulated.

Hi Rose, You won't see them on display at any company as I designed them and instructed the window manufacturer how to make them. They were made by Stegbar windows based on their standard Georgian windows, which are normally powder coated white. I instructed to make them in powder-coated black but to exclude the vertical divisions. I think that most aluminium window manufacturers should be able to make them - but none of them will have them on display. I don't think that they would look very effective if you were using double glazing. This project was completed over 20 years ago (yes I have been in the business that long!) so I hope that the window manufacturers are still making Georgian style sliding doors! Best of luck, Dr Retro of Dr Retro House Calls

Thank you both for your comments. Sorry - I should have said that, whilst we are not looking to sell, there is always a chance with work commitments that we may have to move on and so we always try to renovate with an eye on needing to sell, even if it may not happen. The agent was the agent who sold the house to us, who later told us that one of the issues other potential buyers had was the location of the bathroom, which is in the centre of the house downstairs. At the moment the bathroom is safe and functional, just in the wrong place and dated. If we painted outside, we would paint the whole house.