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Designing the Homes of the Future

Businesses are competing to get their technologies into key demonstration homes in the hope of getting a slice of the future market for sustainable low carbon homes in our expanding cities. But is this the best way to develop sustainable homes?

Since the British government decided that by 2015 new homes should be zero carbon, much research has been ongoing to determine what kind of strategies could not only achieve this but also decarbonise existing homes and address fuel poverty through retrofitting.

The research is now bearing fruit with three approaches reaching demonstration stage.

Nottingham University

The Mark Group Home at the University of Nottingham

In Nottingham, the Mark Group's EcoHouse is due to be showcased on 16 October, where it will display 15 different energy saving and generating technologies, which, the press release says, "have never been combined together before under one roof".

These include a timber and steel frame, phase change materials, rainwater harvesting, air source heat pumps, underfloor heating and sun pipes.

The Leicester-based Mark Group is positioning itself as one of the main companies to take advantage of the government's Green Deal, that provides free loans to home occupiers to undertake certain energy efficiency measures, repayable from savings on the electricity bill.

This EcoHouse initiative is part of the University of Nottingham's 'Creative Energy Homes Project'. It is on the campus of the School of the Built Environment, which I've visited, and which contains several homes, at least one of which is occupied and being monitored.


The British Gas Smart Home under construction at BRE

The second initiative is BRE's retrofit project, The Smart Home, being launched this week at its Watford site. BRE was formerly the Building Research Establishment, a government-sponsored initiative now largely in the private sector.

The house utilises "smart technology" alongside "fabric improvements and occupant empowerment".

The press release for this says it uses "cutting-edge technology, design and building techniques" which "has made the house 50% more energy efficient and halved its carbon emissions".

It includes occupation sensors to control heating, lighting, ventilation, water and security, as well as heat pumps, solar thermal and PV. There is 3mm of insulating plaster, heat and light reflective paint to increase brightness and reduce lighting and heating needs.

Moreover, there are phase change materials in the upper floor walls to moderate internal temperatures, reclaimed timber floors and FSC certified timber as well as recycled uPVC in the windows and doors.

Finally it uses the latest energy saving Velux windows.

Velux' CarbonLight

Velux' CarbonLight Active House

Velux is also demonstrating its own all-purpose prototype house, called the CarbonLight Homes experiment, in Rothwell near Kettering, which embraces its patented Active House principles, a kind of cross between an ambition to be Passivhaus and a smart home like BRE's.

Unsurprisingly for a company that started out by making windows, it aims to maximise the use of daylight and natural ventilation in order to minimise energy consumption.

Sensors automatically open and close windows according to the outside temperature, striving to moderate it to stay within comfortable limits.

Their design is not only about reducing energy consumption to a minimum but also promoting the comfort of occupants without them having to do too much. The technology does it for them, although they can override it.

Now I'm all for taking control out of the hands of individuals - not because I'm a fascist dictator but because I recognise that despite the best of intentions we all forget to turn lights off having switched them on, turn the heating down having turned it up, and close windows having opened them.

Having a building do all this for you means that we don't have to remember and then beat ourselves up afterwards when we find out how forgetful we were.

The emphasis on comfort and indoor air quality in the Active House spec is to be welcomed, since sustainability and environmental performance are not just about energy efficiency.

The Velux house is part of a Europe-wide 'Model Home 2020' project, led by Velux, comprising six demonstration projects, each of which must reflect the different climactic, cultural and architectural conditions of their host countries (Denmark, Austria and Germany).

Velux hopes that developers will take up its model. But how does it much does it cost? It says that a 'LITE' version of a CarbonLight home could be replicated at around £1200 to £1500 per square metre. As the average house in the UK is around 80 square metres, that equates to a build cost of between £96,000 to £120,000 on top of the cost of the land.

Corporate homes?

All of these homes are at least partly financed or sponsored by technology companies who are hoping that their technology will become established in the marketplace of the future.

The research is therefore being led by the needs of intellectual property rights, i.e. whether a patentable idea can be established to generate profit for a company. In other words the race for the home of the future is dominated by business.

In a way this is perfectly understandable. Innovations are necessary to drive forward energy savings in the types of home in which we have become accustomed to live. Companies want to get a benefit from their investment; the Mark Group will be using their Nottingham home for commercial purposes.

On the other hand, I worry that this means that more generic and, possibly equally or more effective, measures to make homes more sustainable and healthy will not be able to gain official approval or traction in the marketplace.

The situation is analogous to the domination in food markets of processed foods rather than basic groceries because there is no longer a Milk/Egg/Vegatable/Fruit Marketing Board with an advertising budget to compete with the likes of Nestlé, McDonald's and Unilever. There has been a consequent negative effect on people's diet and health.

Insulation materials

We have already seen this with the dominance of fossil fuel-based insulation products. I'm a proponent of organic or mineral fibre insulation such as recycled cellulose, woodfibre and mineral wool, as opposed to polyurethane-based insulation. That's because the former generally lock up atmospheric carbon in the fabric of the building for its lifetime, whereas the latter have caused the emission of climate warming gases during their manufacture.

But it's the latter - the fossil fuel-based insulations - that get the most widespread use because of the aggressive marketing techniques used by their manufacturers. They are not breathable materials and may well cause problems with indoor air quality and condensation. These problems may then have to be corrected by deploying further energy-using technology such as air-conditioning or dehumidifiers.

Some of the demonstration houses at BRE and the Nottingham campus are sponsored by the manufacturers of polystyrene-based insulation. One of them is even sponsored by a steelmaking company.


Paint is another example. Completely environmentally-sound paints that are wonderful to use and completely healthy are available, and yet the BRE Smart Home doesn't use these clay-based paints but uses a branded paint that, while being 'low-VOC' (i.e. low on volatile organic compounds that cause indoor air pollution), is not as healthy.


Furthermore, homes that rely on electronic technology to function can break down. In my experience, despite daily use over many years, it's the electronic circuit boards, not the mechanical motors in washing machines, that break down first and need replacement.

Similarly, the evolution of car design to incorporate on-board computers has taken the ability to perform maintenance tasks away from their owners into the hands of professionals whom we have to pay to do things that we used to be able to do ourselves.

Will the same happen to our homes? Will DIY become a thing of the past?

Embodied carbon

Smart homes will also be more energy intensive in their manufacture, increasing their carbon footprint, or 'embodied carbon'.

Velux says that what it calls "a simple building management system" would add "around £200 to £500 per square metre" to the pricetag, "depending on how 'LITE' the developer wishes to go".

It's a question whether the additional climate impact caused by the technology will be offset by its benefits.

Life Cycle Analysis

The Mark Group house under construction: steel skeleton

Velux' definition of an Active House does include that the overall life cycle impacts should fall within limits for overall energy consumption and for the potential for global warming, ozone depletion and eutrophication of water; that they should use over 80% recycled materials, 100% FSC new timber; and that a percentage - in some cases over 100% - of the energy used should be produced on site.
It may be that the life cycle impact of this house will be low, but I can't say the same for all The Mark Group's home judging by the incredible amount of embodied energy that must be in this steel frame, in this picture. Talk about over specified.

Don't get me wrong, I welcome most of the innovations shown in these demonstration houses. We have to try out lots of different things before we get it right.

I also support offsite fabrication for quick onsite assembly of volume homes for reasons of cost-effectiveness and improved airtightness.

Yet in some cases our ancestors also knew a thing or two about building: they used local, natural materials and in hot countries they designed buildings and communities in such a way as to prevent overheating without the need for air conditioning.

It was also possible for families and communities easily and cheaply to build and maintain their own homes.

Ideally, the homes of the future should incorporate the best of traditional building knowledge with the best of modern technology and research; and they should be affordable - which does not necessarily mean high-tech.

These demonstration homes are a step along that path, but I do not believe we are there yet and I don't want to see the process of getting there hijacked by corporations more interested in gaining market dominance.