The Aktivhaus: is this the future of sustainable living?

DEU, Stuttgart, Dokumentation Aufbau Pavillon Wei§enhofsiedlung, Werner Sobek Design GmbH , Fertigstellung: 2014 , DIGITAL 100 MB 8 Bit. - ©Zooey Braun; Veroeffentlichung nur gegen Honorar, Urhebervermerk und Beleg / permission required for reproduction, mention of copyright, complimentary copy, FUER WERBENUTZUNG RUECKSPRACHE ERFORDERLICH!/ PERMISSION REQUIRED FOR ADVERTISING!

Photo reproduced with permission of Werner Sobek Design GmbH , Fertigstellung: ©Zooey Braun

By James Carson

Earlier this year, we looked at a style of building known as Passivhaus, which is playing an important role in creating energy-efficient homes. Now, another concept – the Aktivhaus – is taking this approach even further, graduating from energy-saving to energy-generating homes.

The Aktivhaus concept

Like Passivhaus, the Aktivhaus has its origins in Germany. Stuttgart-based architect Werner Sobek defines Aktivhaus buildings as those which:

  • offset their annual total energy consumption in a sustainable manner;
  • anticipate and react accordingly to relevant changes both inside and outside the house;
  • continuously measure and optimise all energy streams.

Sobek’s idea has been realised in the form of a building called B10. This prototype Aktivhaus – prefabricated offsite and assembled in a single day – is located at the Weissenhof settlement in Stuttgart. It’s an appropriate site for applying a revolutionary concept – in 1927 the Weissenhof estate hosted a housing exhibition that included designs by leading lights in modern architecture, such as Le Corbusier and Ludwig Mies van der Rohe.

The Aktivhaus enacted

On the face of it, B10 is an 85 square-metre box with a full-length window. But its sophisticated design means the Aktivhaus can generate twice as much electric power from sustainable energy sources as it consumes. This means it can not only satisfy its own electricity needs, but can also power two electric cars and a neighbouring house built by Le Corbusier for the 1927 exhibition.

The ‘active’ element in the Aktivhaus is a mini computer, connected to the internet, that monitors weather forecasts and enables the house to respond accordingly, with different rooms heated or cooled at different times of the day. Other elements include a highly efficient heating system, web app-operated functions to control lighting and window blinds, and 17mm thick vacuum glazing whose three layers keep heat in and draughts out.

Werner Sobek believes that the Aktivhaus concept is not only applicable to new homes. “Our system is very helpful for old buildings,” he told the New York Times.

Some might feel it best to leave the imperfections as they are and not invest in major energy improvements and instead rely on the surplus energy from a ‘sister house,’ but the system can also help you decide to make modest changes to the windows or to improve the boiler.”

DEU, Stuttgart, Musterhaus Wei§enhofsiedlung, AWerner Sobek Design, Fertigstellung: 2014 , DIGITAL 100 MB 8 Bit. - ©Zooey Braun; Veroeffentlichung nur gegen Honorar, Urhebervermerk und Beleg / permission required for reproduction, mention of copyright, complimentary copy, FUER WERBENUTZUNG RUECKSPRACHE ERFORDERLICH!/ PERMISSION REQUIRED FOR ADVERTISING!

Photo reproduced with permission of Werner Sobek Design, Fertigstellung: 2014: ©Zooey Braun

Over three years, researchers will study B10’s performance as a real-life residence. The building can later be dismantled and reassembled elsewhere, and when it reaches the end of its life almost all parts of the Aktivhaus have been designed to be recycled.

With construction costs of €100,000 and the technology inside priced at a further €600,000, the Aktivhaus is hardly an affordable housing option. But eventual scaling up of production could drive those costs down.

In the meantime, the ideas coming out of the Aktivhaus project may influence those looking for ways to tackle the ongoing issues of housing shortages, climate change and fuel poverty.


The Idox Information Service can give you access to a wealth of further information on energy-efficient housing; to find out more on how to become a member, contact us.

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Further reading*

PassivHaus … a home for all seasons?

Thermal vision (energy-efficient retrofit for social housing block)

Warmer outlook (energy efficient housing)

Building sustainable homes

Footprint: three Passivhaus projects

Building the future: the economic and fiscal impacts of making homes efficient

*Some resources may only be available to members of the Idox Information Service

Energy infrastructure: a heated debate

Energy_infrastructure_-_geograph.org.uk_-_1080396

Image: Hugh Venables, via Wikimedia Commons under a Creative Commons License

A country’s energy infrastructure is its central nervous system.  Gas and electricity transmission lines, power stations and renewable energy, are the drivers of economic development, as well as keeping our homes light and warm.

But in recent years, a growing sense of urgency has surfaced regarding the future of the UK’s energy infrastructure. Concerns about lack of investment in new power stations have fuelled media reports voicing fears about the challenges of keeping the lights on.

The headline writers may be guilty of some exaggeration, but their concerns are not without foundation. Forecasts by Ofgem, the UK’s energy regulator, indicate that the country’s energy margin (the difference between energy generation supply and peak usage) could fall from 6% at the peak of winter demand in 2014-15 to a possible low of less than 2% just a year later.

And just yesterday, National Grid was in the news with a warning that its capacity to supply electricity this winter will be at a seven-year low due to generator closures and breakdowns.

In stark terms, a report, published this year by the Institution of Civil Engineers (ICE) set out the state of the UK’s energy infrastructure:

“Significant quantities of the UK’s existing electricity generation capacity are expected to be retired soon, with major implications for security of supply unless the conditions to attract investment in new generation are provided. This situation is expected to be further exacerbated as the use of electricity for transport and residential heat increases demand.

And that’s without taking the unexpected into account. The recent serious fire at Didcot power station in Oxfordshire was just the latest in a number of incidents affecting power supply this year. Fires put two power stations in Shropshire and Yorkshire out of action, and four nuclear reactors have been taken offline until at least the end of the year for safety reasons. At the same time, plans for the next generation of gas-powered stations have yet to be enacted, and uncertainty surrounds the commercial viability of new nuclear energy capacity. Added to this complex mix is the contentious issue of fracking, which we focused on in a recent blog post.

For some, the answer to the energy gap lies with renewables, in particular wind power. Proponents argue that large-scale deployment of wind farms offers dual benefits: generating increasing amounts of energy, as well as minimising the effects of climate change.

A report, published earlier this year by the Royal Academy of Engineering (RAE) explored the implications of increasing the amount of wind energy on the electricity system. While acknowledging that large wind turbines have an impact on local communities, the RAE indicated that the installed capacity of wind could more than double to around 26GW, providing around 20% of electrical energy consumed. That might seem like a tall order, but figures from the Department for Energy and Climate Change (DECC) show that in 2011 9.4% of UK electricity came from renewable sources, up on 2009, when just 6.7% of electricity was renewable.

Others are not so sure about the impact of renewables. Recently, former Environment Secretary of State Owen Paterson called for the ground-breaking Climate Change Act to be scrapped. He claims that the targets in the Act for cutting emissions are unachievable, too costly and will not provide the UK’s energy requirements:

“In the short and medium term, costs to consumers will rise dramatically, but there can only be one ultimate consequence of this policy: the lights will go out at some time in the future. Not because of a temporary shortfall, but because of structural failures, from which we will find it extremely difficult and expensive to recover.”

Instead of investing in wind power, Paterson argues, the UK should be looking at four alternative policies: shale gas, combined heat and power, small modular nuclear reactors and demand management.

As the energy debate heats up at national level, some local authorities are taking their own initiatives. Security of energy supply is of great concern to Southampton, a city keen to address strategic priorities, such as tackling fuel poverty, sustaining public services, generating economic development and reducing city-wide carbon emissions.

And so, Southampton City Council has taken a leading role in collaborating with other local authorities to build capacity through local energy generation schemes, large-scale energy efficiency works and local energy networks. The investment shows how seriously the council is taking energy resilience.

At the same time, along with local councils in six countries, Southampton has been a key partner in the European Union’s Leadership for Energy Action and Planning (LEAP) programme. LEAP aims to share expertise among partners to reduce energy consumption and carbon emissions, and increase the use of renewable energy.

Measures such as these are relatively small in scale, but they might prove crucial as we head into another winter.


 

Further reading

The Idox Information Service has a wealth of research reports, articles and case studies on a range of environmental issues. Items we’ve recently summarised for our database include:

Low-carbon transitions and the reconfiguration of urban infrastructure

A new approach to electricity markets: how new, disruptive technologies change everything

Power blackouts in the information age: the impact on emergency services

Is there a future role for coal? (Energy supply)

Taking the lead in a low-carbon future (low-carbon redevelopment in Southampton)

When the lights go out (threats to energy infrastructure)

Crossed wires (energy infrastructure for property developments)

N.B. Abstracts and full text access to subscription journal articles are only available to members of the Idox Information Service.