A small subterranean living space becomes a surprisingly luxurious urban dwelling.

Follow the step-by-step eco-renovation of a 100-year-old Modernisme-style space into apartments in Barcelona. From upcycling to smart water-saving devices and insulating rooftop plants, yök Casa + Cultura is about sustainability and the local culture.

Recyclability is key at yök's eco-renovation. First, preserve everything we can, then recycle everything that has to go and lastly, make sure any new stuff is recyclable in the future.

In the end it needs to work, fit the budget and be easy to install. To divide our spaces, we opted for low-VOC drywalls, locally made in Spain. That way, no floors or ceilings shall be harmed!

Copper is recyclable, but requires a lot of energy to do so. For our plumbing system, we opted for PEX, a crosslinked Polyethylene that is easy to install, non-toxic and long-lasting.

What is the best eco option- longlasting porcelain sinks, 100% recyclable, lightweight LDPE ones or second hand washbasins? Here's the story of how we chose the sinks for our non-hotel in Barcelona.

I believe we made the right decision in choosing Isonat Flex, made of wood fibres, over mineral wool or cellulose to insulate our low-VOC drywalls. Here's how we made the decision.

We are still eco-renovating! Here is what we did to our office, a top floor space in the heart of Barcelona. Insulation, energy-saving devices and non-toxic, recycled materials are key.

Home automation, LED lighting, ceiling fans, insulation, energy monitoring and other tricks will save energy without sacrificing the experience in our holiday rental apartments.

yök commissions upcycled stools by ex homess people and Curro Claret

At yök we do not only work hard to save energy, but also water. According to Airbnb, guests in Europe renting a home use 45% less water than when staying in a hotel. But there is more to a bathroom than saving water; materials also play an important role

Astral Nature has the perfect mattresses: all natural ingredients and locally made just outside Barcelona. However, at yök Casa + Cultura we also needed an eco base. Luckily, Astral made some changes to theirs. The result: green beds, such luxury!

This is my last post about my current eco-venture in Barcelona: yök Casa + Cultura. We believe that good tourism is possible thanks to common sense, eco-design and working for People, Planet and Profit.

Use what you already own to create a space that feels fresh and new.

But where do you put it?

In this age of consumerism, particularly around the holiday season, sometimes its easy to forget that the things we've used the longest often have the most value to us -- but the virtues of reuse just seem come naturally to some

That's what they are doing in Berkeley, and it will spread.

But you'd better return it within 5 days or else you'll get fined.

Realizing that recycling isn't working, the chain will be eliminating single-use cups and coffee bags.

If you’re to take composting to the next level, here’s a list of some less-common items that can also get tossed in your composting bin or tumbler.

We've long known that sea level rise caused by global warming would threaten communities along the coasts, but a new study puts a startling figure on the potential damage. Meanwhile, the Hurricane Sandy Task Force releases a report.

The 6.3kW solar array might not produce enough energy to power the White House, but its symbolism is important.

Download it while you can.

The company uses 90 percent less water than most denim producers.

It's got everything: “Design, construction, love, betrayal, and eventually murder. Just a typical architectural project.”

That's 0.0082677165 inches for Americans, and really thin in either unit.

Could it also be the new 120 Volts AC?

Solidia Technologies' chemistry could make concrete almost benign.

There is more to a house than just walls. Danish company COBOD tells the truth about it.

With ~30+ new posts on TreeHugger.com each weekday, we understand if you miss a post here and there. To keep you up-to-date, here's what we covered on Thursday, July 28, 2011.Animals David explained the difficulties of GPS

With ~30+ new posts on TreeHugger.com each weekday, we understand if you miss a post here and there. To keep you up-to-date, here's what we covered over the weekend, July 29, 30, and 31, 2011.Animals Jaymi told us that

With ~30+ new posts on TreeHugger.com each weekday, we understand if you miss a post here and there. To keep you up-to-date, here's what we covered on Monday, August 1, 2011.Animals Alex Davies informed us that New York dairy

With ~30+ new posts on TreeHugger.com each weekday, we understand if you miss a post here and there. To keep you up-to-date, here's what we covered on Tuesday, August 2, 2011.Animals Lloyd asked is urban chickens are a gateway

With ~30+ new posts on TreeHugger.com each weekday, we understand if you miss a post here and there. To keep you up-to-date, here's what we covered on Wednesday, August 3,

The competition between the hottest solar homes in the nation at the 2011 Solar Decathlon in Washington, DC has been heating up all week and the winners will finally be announced tomorrow. Green design experts will be judging these student-built houses

Show the world your environment with a new TreeHugger and UNEP partnership with Piictu, a photo sharing social network.

YES! Magazine’s 2nd Annual Celebration of People Power with Alice Walker, Frances Moore Lappé, and Makana.

A visit to the Interior Design Show does not shed a lot of light on the subject.

It's about time; they are better for the environment and for your bottoms.

These things should be banned, or at least they should come with a real warning.

Not by a long shot, but the answer is still interesting.

But would you want to sit in a plane with no windows?

Salvaging old IT from corporations can mean big business, and a way to keep cell phones out of landfills.

Sony's environmental focus is fairly simple. In fact, it's the very definition of simple. And we like it.

Samsung is proud to show off a wide range of new toys at this year's CES, including internet-connected washers and driers, TVs you can see through, and more.

We found some really wonderful new devices at the recent Consumer Electronics Show, and it's hard to decide which is coolest!

Before this year's consumer electronics show, we talked about our hopes and frustrations about the industry and event. Here, we sum up what we saw.

We have more choices than ever in the consumer electronics sector, but at what cost does all this "choice" come?

The new machine from 3D Systems has a larger printing platform, and a whole lot of new bells and whistles for 3D printing enthusiasts.

Are we really that dependent on technology now that we can't water our plants without a gadget telling us when to do so?