Developing the UK’s zero-carbon homes

The reaction from property developers to the low carbon homes promise has varied. Barratt Homes has come up with small experimental “eco-villages”. Other developers, such as Bovis, have taken things a step further by implementing low-carbon technology in all their new housing developments.
The zero option

Zero-carbon houses are hard to come by, but there are a few developers taking the initiative. Independent sustainability consultants BioRegional Development aim to make zero-carbon housing and sustainable living an easy and viable option for future homebuyers.

BioRegional, together with London charitable housing trust Peabody and eco-architect company Bill Dunster Architects (also known as ZEDfactory), initiated the UK’s largest eco-village in 2002.

The Beddington Zero Energy Development – or BedZED – is a mixed-use development in south London, comprising 82 residential properties and 100 workspaces and community facilities. All are intended to be carbon neutral.

BedZED homes feature high levels of insulation, passive heating and ventilation systems, photovoltaic panels (which generate electricity from the sun) and design utilising as much natural lighting as possible.

An on-site combined heat and power plant – which uses wood waste from street tree pruning as its energy source – was built to supply the remaining heat and power needed in the homes. BedZED houses are, however, connected to the national grid in order to manage fluctuations in energy generation.

Extra cost

BioRegional claims that the cost of building an eco-home, such as those in BedZED, is around 2% more than properties developed in accordance with 2002 building regulations. But the company’s research shows, it says, that the higher price does not deter homebuyers, primarily because their new eco-home will save them up to £500 a year in fuel bills.

As a prototype for zero carbon homes in the UK, BedZED is not without its problems. A major downfall has been the on-site combined heat and power plant, which stopped functioning over a year ago, meaning that the houses in BedZED no longer qualify as zero-carbon.

BioRegional claims, however, that even without the power plant in operation there is still a 57% reduction in BedZED’s carbon emissions.

A report by BioRegional admits that generating all energy on-site is not always a feasible option. This may be due to the limited space of a development (such as high-rise flats), or because the local renewable energy supply is not accessible from all parts of the site. Using off-site energy generation in these cases, the company claims, would make resources more easily accessible and thus more effective.

Retrofitting

If – or perhaps, when – new houses become zero carbon, that still leaves a vast number of existing properties that will continue to leave a large carbon footprint.

Current housing stock is predicted to make up to two-thirds of the homes that will be occupied in 2050, according to researchers at Oxford University’s Environmental Change Institute. If the UK is to significantly reduce carbon emissions from housing in the next few decades then it seems the focus will have to be on retrofitting existing homes with better insulation and renewable power sources.

Tough target

With very few fully functioning zero-carbon houses in the UK at the moment, the government’s objective for zero carbon homes to be mainstream by 2016 seems a long way off.

BioRegional agrees that 2016 is a “stretching target” but says it is nonetheless possible. “When more renewable energy systems are installed … the costs should come down,” the company says, making eco-newbuilds a more viable option.

But as newly built homes comprise just 1% of UK housing stock each year, the government will need to tackle the carbon impact of existing homes.

Retrofitting presents huge opportunities. British Gas, for example, have already teamed up with local government to offer council tax incentives to homeowners in exchange for buying insulation.

To make any home zero-carbon – and not just low-carbon – however, accessibility to significant renewable energy sources will also be required. Not only will the government have to improve the economic incentives for householders to install domestic renewables. Utility companies, it seems, will also need to become more engaged if any zero-carbon scheme is to ultimately be viable.

Facts: Zero carbon housing in the UK: what’s being done

BioRegional Development Group: A registered charity and sustainability consultancy, BioRegional works on various projects that are aimed to make sustainable living in the UK a reality. BioRegional has formed a strategic partnership with WWF under the name One Planet Living. BioRegional co-founded BedZED, the UK’s largest zero-carbon development to date.

BioRegional Quintain: A company currently working on the development of large-scale mixed-use zero-carbon communities in Middlesbrough, Brighton and London’s Thames Gateway.

Barratt Homes: A major UK builder, the company has developed the EcoSmart Show Village, an experimental low-carbon housing development comprising seven residential properties. Horthram Village, a low-carbon housing development located just outside Bristol, will be the live result of EcoSmar
full article

Eco-motoring 'to help save planet

Is it possible to save the planet by sticking to the speed limit? The government's transport advisors think so.
The Commission for Integrated Transport argues that emissions from cars and lorries still outweigh by some way those from air travel, though aviation is growing as a source of carbon dioxide.

One remedy, the authors conclude in a report published on Wednesday, is for us drivers to have state-sponsored lessons in eco-motoring, an idea that would cost the government little but benefit the planet a lot.

The theory is that the way you drive can be as important as what you drive, and how much you drive it.
Research suggests turning on the air conditioning uses 10% more fuel, therefore producing CO2.

Unfortunately keeping cool by lowering your car windows also increases fuel consumption, as does keeping the roof rack on after that family holiday.

Most of all, driving smoothly is the key to an environmentally-friendly motoring life.

Gentle on the accelerator, thinking ahead, judging the distance to the lights, and stopping without a jolt.



full article

Hydrogen-Based Power Offers Green Alternative for Homes

In a development that marks another step towards the vision of a sustainable, clean future for home power generation, UK company ITM Power has announced the upcoming release of a device which can generate hydrogen in the home to fuel central heating boilers and cookers while drastically cutting CO2 emissions. Set to go into production next year, the ITM electrolyser is designed to utilize off-peak or renewable electricity sources to create its own hydrogen fuel which can then be stored and used as a conventional gas to burn in central heating boilers as well as a fuel for cooking.
Unlike gas and oil, when hydrogen burns it releases no CO2 emissions, merely water vapour, offering the opportunity to significantly cut Britain’s domestic carbon footprint. Stored hydrogen can also be reconverted to electricity using domestic fuel cells or generators to power lighting or other electrical appliances, removing the inconvenience of power cuts for homes and serious supply interruptions for hospitals, schools and businesses.
The system is aims to use a totally ‘green’ supply of electricity (available from wind, wave, solar or hydro-electric power) or alternatively, low cost off-peak electricity

This device depends upon an electrolyser stack of 10kW electrical input operating at pressures of 75 bar.

The company sees this as a major breakthrough in sustainable, non-polluting hydrogen technology and a major advance towards the UK Government’s goal of achieving a zero carbon new housing market by 2016. Currently domestic consumers account for over 20 per cent of the UK’s CO2 emissions.

Like the “Home Energy Station III” developed by Honda R&D and technology partner Plug Power, the ITM electrolyser system can be used to power a family car in addition to its use in the home. Later this year ITM Power plans to unveil a hydrogen home refuelling station for the automotive market and a converted bi-fuel petrol/hydrogen car based on the Ford Focus. The company aims to demonstrate that the car can be refuelled using hydrogen generated by a home electrolyser and can complete an average daily commuting journey without the need to utilize petrol.

“ITM Power is developing products which will not only revolutionize energy sources for the home but make a significant contribution to cutting CO2 emissions,” explained the company’s CEO Jim Heathcote.

“With stored hydrogen’s ability to provide not only fuel for heating and cooking but power, either through a conventional generator or a fuel cell, the prospect of energy self-sufficiency without the dependence on fossil fuels has moved dramatically closer,” he added.

full article

Concrete House

Australian Architects Peter Poulet and Michael Harvey contemplate concrete’s green side with The Concrete House, a free-flowing assembly of gravity-secured precast columns and slabs that the designers call a “commitment to living sustainably”. With renewable energy systems, a green roof, rainwater harvesting and waste minimization, the design tries to prove that concrete is an environmentally appropriate choice.
The challenge is part of an ongoing debate. Worldwide, concrete is the most widely-used construction material with over ten billion tons produced annually. In the US, the dubious manufacturing process churns out over two tons of concrete per person per year with a heavy CO2 burden – in total about 7% of global CO2 emissions come from concrete production.
At the same time, the material possesses a unique structural efficiency and inherently green qualities like a capacity to reduce recurring embodied energy, high solar thermal performance, low maintenance requirements and high durability. Variations of concrete with high solar reflectance are considered for heat island mitigation, and with no-offgassing, concrete is an interior finish that meets IAQ standards. Substituting Portland cement with fly ash, using recycled aggregate and a locally fabricated supply can reduce concrete’s environmental impact.
In The Concrete House, curvilinear thermal mass on the southern exposure transfers constant temperatures to open spaces on the north where folding doors allow natural ventilation and daylight. A green roof helps increase the structure’s thermal performance and is central to on-site graywater recycling and rainwater harvesting. The water can be stored in the precast concrete columns.
Intended for solar thermal hot water and solar photovoltaic power, the pavilion-like design creates an immediate connection with the environment that carries through to energy and resource consumption. Based on an inexpensive, widely available and easily applied material, The Concrete House can be assembled in less than a day.
Poulet and Harvey’s design puts concrete in its best light with a concept that highlights the energy laden material’s role in green building. In a minimalist application such as The Concrete House it seems that concrete’s greenness is not cemented in black or white but filled with innovative shades of gray.
full article