Fiddling with the Roof

Recently, I ventured up the ladder, swung a tentative leg over the parapet and uncovered some of the mysteries of the Casa de Toh rooftop.

The entire roof is divided into sections and each section has a 30 cm wall to collect the rainfall and direct it to key drain holes located at one end of the section. The drain holes are the beginning of the downspout drains which are located within the walls of the house. Most people look at the houses and wonder why the look of each house is so clean and uncluttered. By locating the drains within the walls, the houses maintain a simple facade and without ugly downspouting, the clean lines add a simple elegance to the construction. The rainwater proceeds down the spout and is redirected either to the garden or the one of the underground wells.

Similarly, airconditioner drains are also located within the walls, keeping everything neat and tidy.

Although the roof may last for centuries some maintenance is required. Like most houses around the world, the leaves and debris need to be gathered up. A sealer called impermeabilizante (even Mexicans have trouble pronouncing it!) is often added as extra protection. This roof has some deterioration which requires another layer of concrete to stop it leaking.

Below is a picture of the new bathroom roof. To the left is the skylight for the washbasin area in the bathroom. This skylight will be capped with a layer of glass to prevent the water getting in. In this case the water drains to the right and the downspout is located in the lower right side of the picture. Already, the debris is collecting and similar to most parts of the world, periodic cleaning of the debris will be required.

The image below is the area for the indoor garden. A large section of the roof has been removed allowing the breeze (and the rain) to enter the house. The rebar will eventually be removed and wooden beams will be inserted across this space. At the lower end of the picture you can see green pipes which connect to the hot water system (a technology called “Tuboplus”) and the vent for the toilet in the front bathroom.

On the whole, the system works very well and properly maintained, the roof will last for centuries.

Art Nouveau in Santa Ana

Originally in the colonial times, the slaves lived in the Santa Ana neighbourhood where Casa de Toh is located. Then in the 1800′s,  the city started growing  and the Spanish began moving into the  area.

In the latter part of the 19th Century we had a golden age in Merida as the hennequen (sisal) trade was booming.  Those people who had money regularly travelled to Europe.  They were experienced in  European ideas including fashion, and style and sent their children to study in France, Germany, Spain and other countries.  In both architecture and the arts, people started to become familiar with European habits and trends.

Then in the early part of the 20th Century, the hennequen industry started to decline and by the 1930′s there was very little money in Merida.  However, people clung closely to the European sensibility and wanted to keep up with European style.  One of those styles was Art Nouveau and although it was not broadly adapted, that influence was very strong in Merida.  In particular, the organic aspect of Art Nouveau had a great appeal and the local Yucatecans with their  strong history and culture of handcraft quickly adopted this particular European style.

The original tile in the front room of Casa de Toh.

Between the wars, Mexico was in a bad situation and there wasn’t much money. Yet people still wanted to keep what they remembered of the European tradition and in this little house, they looked at what the wealthy people had, and tried to adapt a modern style on a smaller scale. One way to adapt to the Art Nouveau style was through handcrafted ironwork and decorative tiles.

Tile from the kitchen at Casa de Toh.

And of course, it’s the handcraft technique that is very important in Casa de Toh. For example, as the hennequen industry grew in the Yucatan, companies imported iron for the machinery  and the Mayan workers learned how to work with metal.   Although it’s a little old fashioned today, the ironwork in these Merida homes is wonderfully handcrafted.  At this moment it would be difficult to find someone who could handcraft this iron as nothing is welded. It is all tied together with twists and rivets and is quite amazing.

Ironwork from the front door of Casa de Toh.

It’s important to keep these Art Nouveau elements in the house.  Oddly enough the wealthy people made exact copies of what they saw in Europe.  Those with less money however adapted the Art Nouveau style to a traditional Yucatecan home and came up with something original and different. It is this handcrafted Mexican adaptation of Art Nouveau that makes Casa de Toh an interesting house.

Guest Author: Architect Cecilia Sanchez.

A Walk through the House

At the beginning of August we are progressing very well with construction.  Most of the floors are now in place and the walls completed.

Here’s a site walk-through starting at the front room of the house, walking into the central area of the home, past the indoor garden into bedroom two.  From there we inspect the rear bathroom, venture into the terrace and down the yard to the pool where you will see the laundry construction.  We duck into the laundry which is behind the pool and then look at the rest of the backyard.

Well Well Well

This week, workers were laying down some drainage pipes across the terrace and almost fell into a well.  It was a complete surprise to everyone, as it’s located right at the back of the house where you would least expect it.  The well is about 10 metres deep.  It was a common practice 70 years ago to route the grey water of the house (bath, shower and sink water) to a well. It’s always a handy thing to have and we may follow suit, routing some of our grey water or rainwater to this newly discovered well.

A cap is created for the new well found under the terrace.

We also require two wells for the pool.  One well is needed  for pumping water up from the underground aquifer beneath the city to fill the pool. It’s much quicker to fill a pool using the aquifer and in the long run, also saves a little money. The other well is to allow you to drain the water from the pool (maintenance etc).

The supply well was drilled down about 17 metres when we hit pure water.  The drainage well was a different matter.  Mud was struck around 8 metres and again the drillers needed to go down to about 17 metres to create a good drainage well.

The drilling rig was an amazing piece of equipment that broke down like a Transformers Toy into small pieces.  Each piece was then carried through the front door with enormous grins and chuckles as everyone watched a large drilling rig breakdown like Lego and magically reappear on the street in one piece again.

Drilling to create a drainage well for the pool.

There is also another well on the property shared with the neighbour that also goes down about 10 metres.  So at the last count we now have four wells on the property, although it would seem that number could go up at any time.

Walk through with Skype Video

One of the challenges of building a home in another country is dealing with the day to day decisions that must be made.

As this is at least a four month project, it was impossible to spend the entire time on location. Yet there are many decisions to be made each day and it is very helpful to be able to see and discuss each issue while on site.

As the capital of the Yucatan with excellent facilities in health care, education and industry, Merida has an very good online infrastructure. A very inexpensive Dell netbook was purchased ($279 CAD) complete with a small webcam and Skype was installed. Cable and wireless internet were then installed in the house by Cablemas.

Each day, Architect Cecilia Sanchez arrives at the house and connects to Skype with the Netbook. She then makes a Skype video call to Canada. The Netbook is small enough to be carried on one hand and she can then walk through the site commenting on progress, asking questions and quick convenient discussion can take place on any issue.

Here is an edited recording of a typical collaborative session using Skype Video. The Architect reviews the height of the wall, explains pool levelling and demonstrates where one or two trees are to be cut. (Note: some quality is lost in the recording process – the actual session is much clearer)

While nothing replaces being on site, this approach is a great compromise. It makes decision making much easier, brings peace of mind on how each area is progressing and keeps the lines of communication open between architect and client. It’s an extraordinary experience to remotely walk through the building each day, and talk about the changes, and a terrific solution to the tyranny of distance.

Water, Water Everywhere

There are many places on earth where a barrel of water costs more than a barrel of oil – it’s our most precious resource and one of the key issues of sustainable architecture, especially in such areas as conservation, treatment and disposal. We talk about it every day and one day I sat down and discovered there are at least seven different kinds of water that have to be managed at Casa de Toh.

Potable water
Although the mains water in Merida is treated, the hot weather and old pipes create a situation where the water is not always safe to drink. A large percentage of the city simply purchases 20 litre containers of drinking water, however this is not the most sustainable solution. Osmosis systems are available but these usually require a water softener system in order to operate. There are some promising filter systems coming from India and the UK but these systems are not readily available in Mexico yet. Our approach for the moment is to install the pipes for a water softener and osmosis system, and when the budget permits, we will go to the next level. In the meantime, we will get potable water delivered. At least bottled water is delivered in electric trucks in Merida, so the carbon footprint for delivery at least is a little lower.

Drinking water for the workers.

Mains water
Mains water is supplied by JAPAY and one of the main problems in the Centro Historico district is pressure. As we are installing all new pipes, we have some measure of control, although choices in faucets are more limited. Again, when the budget permits, we will probably install a water pressure system to improve the flow throughout the house. Apart from the 750 litre water tank, we have also installed a backup 1000 litre cistern for emergency use.  When hurricanes strike, water supplies are either compromised or cut entirely.  Should this situation occur, we will have enough water to get through a week at least.

Grey water
Grey water is the water collected from the shower, washbasins and the laundry. Completely separate pipes have been installed to these areas and the pipes go directly to the garden. Eventually we will collect the grey water in a holding tank and use it to flush the toilets. In the meantime, this water will keep the garden going during the dry season. There are now a number of garden friendly soaps and detergents on the market.

Black water
There is no sewer system in Merida, so all black water (sewerage) must go to the septic tank. See a previous post on how we are handling the septic system.  Visit Mother Earth News for more information how septic systems work.

Pipes in the first bathroom

Well water
There are no rivers in the Yucatan. Water seeps down through the limestone and forms natural pools known as cenotes. It is common in the city to drill down and create a well to supply either the garden or the swimming pool. Due the septic situation however, care needs to be taken where you  drill. In our case although there is an existing well on the property it is most likely contaminated.  We will drill a new well in the centre of the property. This water will be used to fill the pool.

Pool water
We were faced with a number options when considering the type of pool water system to install. The four main systems are:

• Ozone: expensive and  basically for commercial systems – ozone is a hazardous chemical and requires trained technicians to operate.
• Ultra violet: while this system is a little friendlier, the lights don’t last long and it’s not that effective in tropical climates.

• Salt water: This system is hard on equipment and pool surfaces and while it’s a little more pleasant to swim in, it can also be ineffective in tropical climes.

• Chlorine: we decided to opt for the tried and true.  The amount of chemical required to provide safe swimming is disconcerting at times, but nearly all the recommendations and advice from others has been to adopt this system for the Yucatan.

Pool water needs to be filtered and treated.

Rainwater
With Merida’s large system of underground pools beneath the city, rainwater collection is not a priority. We will run the downspouts into the grey water pipes so that at least the garden will receive some benefit. In the future the option will be there to collect the water.

The Casa de Toh project has become a poignant reminder of how critical water is to our lives. We often take these systems for granted and it isn’t until you have to make decisions on how you are going to manage your water that you realize it is essential to every waking moment of our lives. How we manage this resource as individuals and as nations is  a central question for  the years ahead. For some quick stats on the water crisis, visit the website Global Issues.

House Recycling

Recycling at Casa de Toh has been full of surprises, particularly when it comes to building techniques.

In order to build the pool, workers first had to use a jackhammer to remove large sections of solid limestone and rock. These large chunks of rock were then reused to build the pool wall.  The remaining rubble (or escombro) will be used as landfill to create a platform next to the pool, and a garden pathway. You can’t get any more local with materials than that!

Excavated rock is reused to create pool wall.

The original kitchen also came with large wrought-iron gates. These are common in the Yucatan, allowing you to lock up the house while letting the breeze move throughout the house while you are gone. The front door and window also has similar wrought iron detailing.  The large gates will be reused in the terrace and the ironwork on the doors and window will be restored and incorporated into the new window and front door.

The original ironwork will be reused in the new doors.

Where possible, we are also reusing the original “pasta tile” floors.  The front section of the house will retain these beautiful tiles and the kitchen will also feature these tiles.  These encaustic cement tiles were very popular in the 19th Century and can be found throughout the Centro Historico district of Merida.

Original pasta tile will be restored where possible.

Perhaps the biggest recycling project however is the house itself.  Rather than build a new house from scratch, reusing the existing structure is much more sustainable and like many sustainable projects, saves money at the same time.

Recycling the house (it just takes a little imagination!)

Both Historical and Sustainable

Mexico is a land where resources for many is scarce and the culture celebrates thriftiness and economy.  The vast majority of the population live in small houses and with the relatively high cost of energy, most people are very careful with their electric and gas usage.

Houses are designed to maximize natural light, find the breezes and utilize shade to reduce energy consumption. The houses are generally made from concrete with tile floors so in the Yucatan for instance most of the materials are local. The concrete house acts as a huge thermal bank as well levelling out the temperature of the home.

Small houses also require fewer furnishings, and the emphasis is on family and community rather than consumption.

When thinking about a sustainable approach to construction in the Yucatan we soon realized that simply building the home in the same way it had been done for hundreds of years was the way to go. This isn’t to say that we aren’t employing recent ideas and technologies, but rather acknowledge that sustainable housing isn’t a new idea and that the past has a lot to offer us.

From the past we are taking a traditional approach to light and air, utilizing the south-east/northwest breezes with strategic windows and doors and an open roof area.  The traditional stone walls are shared with the neighbours to create a  two foot thick walls where the temperature remains constant.

From the present we are taking LED lighting, energy efficient fans and as a last resort – efficient air conditioning, although we antiicipate for much of the year, air conditioning will not be needed.

The photograph below shows a long thin window in the shower area of the bathroom.  This window lets in light and air from the indoor garden to the bathroom creating a natural breeze throughout the front area of the house. It also helps to “dry out” the bathroom which is always battling moisture.

Indoor Garden Takes Shape

One of the main challenges  of rebuilding this traditional Merida home was how to introduce more natural light and increase the movement of air throughout the house.  Arquitectura Cecilia Sanchez suggested we take the central room of the house,  cut a hole in the roof and create an indoor garden.  This great idea brings many benefits and provides a unique feature to the central area of the home.

The hole measures 2.5 metres by 1 metre and would be permanently open to the elements allowing the rain and sun to fall on the garden.  Two key breezes would be created flowing from the garden out to the front door and another through the bedroom to the backyard terrace.  This increase in the breeze keeps the house cooler and reduces the amount of time running an air conditioner – keeping energy costs lower.

The indoor garden also introduces a flood a light to the house making the area feel larger and brightening the atmosphere.  With some specially placed windows, the garden light also flows into the shower area of the first bathroom and into the second bedroom – again reducing energy costs and giving the house a light airy feel.

The garden plants also help keep the air fresh and add to the “nature” theme that is a key to the interior design.

The garden can be closed with sliding glass doors which is important when considering the “mosquito factor.”  The doors also keep the water in during tropical storms or those odd days in winter when the temperature drops below twenty degrees celcius.

This first photo shows progress to date with the light now flowing into the home.

This second photo is Cecilia Sanchez’s original concept from 3D Max file. The garden will be planted in the space to the right of the photo.

A Septic Situation

So it’s decision time in the sewer-free city of Merida – What septic system do we install?

There are basically three options:

• Traditional Mexican system with large concrete tank buried underground
• French style – smaller plastic system which is cheaper but requires greater maintenance
• Biodigestor – A different method of breaking down the sewage into a reusable mixture.

While we were initially leaning toward the biodigestor, the layout of the house poses a problem.  This system requires the biodigestor to be pumped out every six months or so and the only way to do so would be to drag the pump hoses through the house from the street.  Not only would it require an extremely long hose but could easily damage furniture etc.

Plan B! – Since the location of the septic tank can’t be changed and we decided to go with the traditional approach.

Here is a photograph of the original septic tank which we are filling in.

Here’s a great resource for more info on the septic system:

http://www.motherearthnews.com/Modern-Homesteading/1989-03-01/Water-Retention-Cleaning-System-Septic.aspx