4. Hemp Cottage in County Down, Northern Ireland

Built in 2008 for a 90-year-old client, the Hemp Cottage is an unassuming eco-build constructed entirely of natural material. This simple, single-storey structure is flooded with natural light and sits on the edge of the fast-flowing Ballynahinch river in the middle of an apple orchard and was built for just £100,000.

"We'd been trying to find a method of building a low-carbon, energy efficient home that was simple and affordable, using natural materials. Hemp and lime mixed together answered all of those needs," says architect Tom Woolley of Rachel Bevan Architects.

The main frame of the building was built using locally sourced Douglas fir, the roof partially turfed and stuffed with 350mm of sheep wool insulation. The studwork was then cast with a hemp lime composite. "Whatever the temperature is doing outside," says Woolley, "the temperature inside stays exactly the same." Not only does 'hempcrete' have impressive thermal performance, it absorbs sound and humidity, creating a cocooned yet breathable construction.

Such is the airtightness of the hemp, the building doesn't need plastic membranes in the walls. This, according to Woolley, makes Hemp Cottage truly deserving of its eco status.

"Plastic, polyurethane and other petrochemical based materials are not eco because the materials used to create them have been responsible for CO2 emissions and wastage of valuable fossil fuel resources. It is far better to use crop-based renewable materials such as hempcrete. These materials are also free of toxic chemicals such as flame retardants and thus ensure healthier buildings."

Hemp Cottage is now available as a holiday rental, allowing everyone the opportunity to experience a natural, breathable dwelling. "We get fantastic feedback from people who stay in the cottage," says Woolley. "People comment on the wonderful indoor air quality." And, of course, there's a discount for anyone arriving on foot or by bicycle.

For more information, visit the Hemp Cottage page at irishcottagesdown.com.

Read more:

1. Marsh House in Nottingham

2. 100 Princedale Road in London

3. Underhill House in Gloucestershire

5. The Pavilion in London

6. Plummerswood on the Scottish Borders

7. Lammas in in North Pembrokeshire

8. Zero Carbon House in Birmingham

9. Lilac co-housing project in Leeds

10. Slip House in London

We're asking you to vote for your favourite eco home. One voter chosen at random will receive £150 worth of gift vouchers for Nigel's Eco Store. Cast your vote here. Voting closes at 23.59 on Thursday 24 April 2014.

With thanks to: the Green Building Council, Hattie Hartman, sustainability editor at the Architect's Journal, HAB housing, The Green Press, Green Sky Thinking, Superhomes, the Centre for Alternative Technology, BREEAM, and The Built Environment Centre for Northern Ireland.

Interested in finding out more about how you can live better? Take a look at this month's Live Better Challenge here.

The Live Better Challenge is funded by Unilever; its focus is sustainable living. All content is editorially independent except for pieces labelled advertisement feature. Find out more here.