When he comes to stay he remarks that English houses are always so cold.
I've been thinking about Hans Thomas and his cosy home this winter, while here the green debate gets mired in a mixture of eco-fatigue and economic uncertainty.
Back in 1915, when Hans Thomas's house was built, nobody had even imagined a world where people measured and traded in carbon emissions and put slivers of silicon on their roofs to convert sunlight into electricity. They just built houses like that because they wanted to keep warm, at a minimum cost.
We've had the know-how to build homes with little or no heating requirements for centuries but a combination of profit-conscious developers, poor building regulations and a lack of public interest has meant we've chosen not to.Now soaring utility bills and the issue of climate change are finally making people wake up and start demanding homes built to a better standard. Failing that, home owners are either retrofitting their properties or they are giving up on the conventional routes and building their own. It's a small and slow start, but I'm prepared to bet that in 50 years' time the idea of building a house that actually requires central heating will seem ridiculous and laughable, or will even be illegal.
Overall things are moving in the right direction, although there have been setbacks. Remember eco-towns? They have diminished from 15 to four projects, one of which, in Cornwall, has run into legal problems and has been effectively mothballed.
While some of the eco-towns were clearly planned for the wrong, middle-of-nowhere sites, architects' designs for the eco-towns' houses do offer exciting new ideas both in the look and the materials used in new homes.
The Bicester eco-town has planning permission for a 393-home "exemplar" phase and work begins later this year. Gary Young, a partner at Terry Farrell, the architecture practice behind Bicester eco-town, says this represents the largest development of Code Level Five homes in the country.
He says that one of the reasons why the green homes idea has only taken off slowly in this country is that until recently, energy costs were so low that the idea of having a home with low or no running costs did not seem important. "Energy security will be increasingly an issue over time," he says.
According to figures from the Department for Communities and Local Government, just over 28,000 homes to Code Level Three (a measure of energy efficiency) and above were completed in the 12 months to September 2011. This compares to just 13,000 in the previous 12 months.
Although few houses have been built to the very highest Code Levels Five and Six, even homes built at Code Level Three and Four will offer their owners huge savings on utility bills. Since the Code for Sustainable Homes was introduced in 2007, a total of 43,000 low-energy homes have been built.
They are not to everyone's taste, of course. Studies conducted by the NHBC Foundation, an industry research body created to help builders meet the Government's zero-carbon targets for homes, conclude that so far house buyers "aren't ready" for low-energy homes, citing design, particularly, and fears the technology to "run them" will be too complicated. Sales of new eco-homes at the publicly funded Braes of Balvonie eco-village in the Highlands south of Inverness have been sluggish, even with promises of utility bills of under £100 a year.
"This is the first development of its kind in Scotland and the economic situation hasn't helped," admits spokeswoman Pauline Gregory. The architect-designed homes present a challenge to buyers used to conventional-looking homes.
Using cutting-edge materials and clad in copper, zinc, exposed rubber and resin, some are designed to continental "Passivhaus" standards and others completely rethink conventional house design, such as a new "suburban loft" and homes with two front doors. Personally, I think they are exciting and a refreshing change to the grim swathes of red-brick boxes associated with many new estates.
What these and all new eco-homes do is challenge the conventional house-building industry to raise its game. One such house is the extraordinary Balancing Barn in Suffolk, designed by Mole Architects and Dutch firm MVRDV. Even though half of the house sticks out into an abyss and has nothing but 15m of air beneath it, because of the materials used to build it, it achieves energy-efficiency levels 20 per cent higher than current regulations.
Architect Meredith Bowles of Mole says he is currently involved in a social-housing scheme which, as an experiment, is building half the homes to Code Level Four and the other half to Passivhaus standards (see box, right).
"The difference in building costs is around £6,000-£8,000 on a £100,000 house. To me that sounds like a bargain considering the savings the homes' occupants will make.
"Designing to Passivhaus standards should be the norm but regulations don't require it so builders don't do it."
One issue that may be a sticking point is a cultural one, says Keith Hall, editor of Green Building magazine. "Passivhaus is a great concept, but it is not for everybody. A Passivhaus means it has to be airtight; in this country we like to be able to open the windows."
Keith has spent the past few years turning his ancient, earth-floored, completely draughty old farmhouse in the west of Wales into an energy-efficient home which generates 170 per cent of his energy needs with a combination of wind, water and solar power. His advice is to tackle each of the four elements of a home's fabric: roof, walls, floors and windows and doors systematically. "It's not rocket science and it doesn't have to cost the earth," he says. "Mega-insulate the roof and if, like me, you have solid walls either internally or externally, insulate them."
Keith's low-cost solution for his internal walls was polystyrene tiles stuck to walls rendered with lime, then plastered over with bonding.
While we have achieved energy savings on our own Twenties home (see Superhomes for more on retrofitting), I'm tempted to build our own next time. Self-build is increasingly popular, a sign that home owners are dissatisfied with what the house-building industry is currently offering and, with the introduction of kit houses, you no longer need to be a millionaire grand designer to build one.
Trevor Walshe of Svenskhomes, a Swedish kit house firm, says interest in the company's houses has increased significantly since it introduced the structurally insulated panel (Sips) system last summer. "As well as halving the build time, the off-site manufacture means much less can go wrong during the building process."
The homes, and other kit houses which come at better than Code Level Three as a minimum, are one reason why self-builders – 13,000 self-built homes were completed last year – are now the largest section of house builders in the country.
While the Government drags its feet on building regulations and house builders worry about profits, British home owners are busy doing what they do best: getting on with it by themselves.
Low2No, Helsinki, FInland
As a European country with one of the most brutal winters, it was hardly surprising that Finland would invest in low-energy building. “Low2No” or “Airut” is a redevelopment of Helsinki’s former docklands district, consisting of apartments, offices and green spaces for urban farming. The Finns’ beloved individual electric saunas, common in most homes, have been replaced in Low2No with a shared public one, powered with a wood-pellet stove, as the Vikings used of old. Exhaust heat from the sauna will be channelled into heating communal areas.
The 200 apartments will all be built with high insulation levels, low-emissivity glass and photovoltaic panels on upper roofs. The development, to be completed in 2014, will also feature the world’s tallest timber-framed tower block.
Berlin-based architects Sauerbruch Hutton estimate the community, “an international paragon of sustainable urbanism”, will become carbon negative within six years of completion. Residents will have real-time digital displays telling them the size of their carbon footprint and how much energy they are using.
Over the past 10 years, we have been, in a rather piecemeal fashion, improving our Twenties house, writes Sarah Lonsdale. It used to be terribly draughty – until last year, the living room door would rattle at the slightest breeze as if some long-dead Brontë heroine were trying to get in.
Although it will never be perfect, we finally feel we have plugged enough gaps to make a difference – and have just received a £200 rebate from our gas company. One of our simplest and cheapest solutions was to remove the letterbox opening from our front door, replacing it with an external wall-mounted one and repanelling the door with extra insulation.
We added cavity wall insulation, increased the roof insulation by 300 per cent, added floorboard insulation to the ground floor and either double glazing or secondarily glazing our windows.
Passivhaus standards require high levels of insulation and airtightness. Passivhaus houses need 15 kWh/m2 to heat compared to 120 kWh/m2 for a conventional house, reducing a £1,000-a-year heating bill to £0-£300 a year.