So much is happening on-site that I do not know where to begin our update. Fortunately, our contractors are good at multi-tasking and can execute separate items of work simultaneously.

An important milestone last week was the completion of all the major planned concrete work on-site. The last item on the list was a small roof slab for the pump room located below the deck. This therefore seems to be an appropriate time for us to talk about the use of concrete in our project.

As I mentioned in my last post, we have tried to reduce the use of concrete to the minimum in our project. The reason is the inherent negative environmental impact of cement use. The production of Portland cement is known to account for 5 - 8% of global greenhouse gas (GHG) emissions which are the major cause of climate change. The high emissions are due to the chemical process that produces cement and as a by-product generates large amounts of carbon dioxide. There is little that can be changed in the cement producing chemical process and hence the resulting emissions. This puts the cement industry at the forefront of global environmental and climate change debate. Link to a NYTimes article on the topic.

View of the living room with 40cm wide basalt load bearing walls and two corner columns to allow for extra-large front and back openings

In India, most buildings are built with a structural frame of concrete beams and columns. After this, the walls are filed in with brick or other building blocks. In our mission to reduce the amount of cement use, we decided very early on to design our structure with load bearing walls.This strategy is more feasible (and actually the more obvious and practical solution) for a building like ours that is mostly built on the ground plus one floor (as a result the primary load on the structure is the roof and not multiple floors above). All our external walls are built with basalt or laterite stone, both locally sourced natural materials that take the weight of the structure above. The only need for concrete columns, total six in number, was to allow for the extra large openings designed in all our rooms.

As a second step, we decided to use fly-ash cement in place of regular Portland cement in our concrete mixes. Fly-ash cement is sometimes called green cement as it replaces between 15-25% of cement with fly-ash. Fly-ash is the by-product from burning coal. Therefore, fly-ash cement reuses industrial waste. The performance of fly-ash cement is also completely structurally safe, as it must follow the national codes for design and construction of concrete, as per IS codes 456-2000. In addition, fly-ash in concrete is known to improve the long-term strength of concrete, reduce corrosion and permeability. Here is some more reading material on Fly-ash cement.

After using fly-ash cement in our concrete mixes, the only difference that we found is that a fly-ash concrete mix takes slightly longer to set, so contractors prefer to use the quick drying Portland cement. Other than that the performance and workability has been comparable to regular Portland cement.

While laying the RCC slabs using filler blocks and fly-ash cement

Another construction innovation employed by us in our quest to reduce the amount of cement used in the project was the use of filler slabs in place of conventional reinforced concrete (RCC) slabs. The science behind filler slabs allows for a replacement of up to 30% concrete in a RCC roof slab with lightweight filler and non-structural material such as bricks, tiles or earthenware. The idea is that in a RCC slab, the upper part is subjected to compressive forces while the lower part experiences tensile forces. The concrete in RCC is good at supporting compressive forces and steel good at tensile strength. Hence, there is no structural need for concrete in the lower part of an RCC slab. As a result, the gaps between steel reinforcement can be filled in with lighter material (even waste material such as bottles, old roof tiles or broken bricks). Filler slabs also contribute in reducing the load of the slab itself therefore reducing the amount of weight that falls on the vertical structural members (load bearing walls, or columns) and foundations. Read more about filler slabs.

For use as filler material in our project, we made simple mud blocks on site from the earth excavated from foundations. These blocks were sun-dried. As a result, we used no new material or spent any additional energy in making them or transporting them to site.

Filler blocks made with excavated earth from site being sun-dried

Filler blocks that were made on-site ready to be used

View of filler slab from below after removing the shuttering

In our experience, a big deterrent against the reduction of concrete in building construction is the unwillingness of structural engineers to work with any structural solutions other than the conventional concrete frame structure. The calculation models used by structural engineers don’t seem to be designed to incorporate load bearing capacity of walls and reduction of the slab’s weight by using lightweight filler material. Along with creative architects, the building industry also desperately needs creative engineers who understand the long-term implications of their work and input on the environment.

Finally, I guess the follow-up question is why more people are not building with load bearing walls, fly-ash cement and filler slabs. The only reason that comes to my mind is the inertia to adopt new ideas or perhaps laziness. The building industry fails to educate their clients and together adopt obvious and simple steps towards building a greener building, reducing the pressure on existing resources and ensure the long-term sustainability of our planet.

Because they can look like this. 

A country house in Formentera, Spain courtesy '

the style files

'. 

I firmly believe that country homes is a unique architectural genre and building them to look like five-star hotels is the easiest way out. Country homes should celebrate their location and be a part of the surrounding countryside by using local materials, local traditional construction techniques and rustic interiors/ furniture. 

Another key element for cozy country homes is their relationship to the outside. In the most enjoyed homes in the country, the outdoor spaces are as important if not more than indoor spaces. After all, the reason to be out in the country is to reconnect with nature, to de-stress and inspire, all in an effort to enrich the patron's quality of lives. Outdoor spaces are also important to entertain while spreading the joy to family and friends.

Country homes provide the perfect backdrop to indulge in the simple rustic country life with its treasures of exotic fruits, fresh farm produce, tropical drinks, and traditional robust recipes.

Why build a house in the country if at best it feels just like an expensive apartment in the chaotic city? when there is the opportunity to build and enjoy something like this ...

This is the silvery-white landscape of Karmal Ghat, a forest area that one passes while on their way to the southern tip of Goa before the Cotigao Wildlife Sanctuary.

There are deep Eucalyptus forests with rows of ghostly white tree trunks that make the air heady with the smell of herbal eucalyptus oil.. a real treasured experience...

This is a local vegetable that grows in the wild in Goa in the monsoons. It looks very intriguing and tastes like meaty beans... 

Can anyone help me find its name? and any other interesting information/ properties ?

View of the river and hills from the living room terrace

It is the month of July and we are right in the middle of monsoons in Goa. Monsoons in Goa bring with it torrential rains with gusty winds that sometimes continue for days without interruption. Most people agree that monsoon is the best time to be in Goa. Everything gets covered with a carpet of green. Plants grow several inches as if they were fed by artificial growth hormones. The sights and sounds of Goa in the monsoons are therapeutic in the most natural way.

Now let me tell you how it feels on our project site when it rains. First, you hear the rain approaching from a distance, rushing towards you. You see in a distance that the hills begin to blur from view. Then you can hear it above you but you miraculously remain dry due to thick tree cover. Finally, you start to feel a light spray of water that is escaping through the leaves. That is when you smile to yourself and decide whether to dash indoors for shelter or in the open to join in the fun...

From that romantic vision, let us turn our attention back to matters of construction, matters concerning brick, mortar and cement. As I explained in our last post, with the rains in full swing we are concentrating our energies to completing interior construction jobs. Last week on site, we completed the construction of internal partition walls in the main house. The material we have chosen for the internal walls is fly-ash bricks.

Fly-ash bricks being delivered to site

Fly-ash bricks are made with fly-ash that is a waste product from burning coal in power plants and sponge iron plants. This fly-ash when mixed with gypsum, lime (both also industrial waste products) and sand can be used to produce a viable building material in the form of fly-ash bricks. As a result, fly-ash bricks constitute 75% post industrial recycled material by weight. The performance properties of fly-ash bricks are also known to be comparable and in some cases better than regular brick, with high compressive strength, low water absorption, good thermal and sound insulation and no efflorescence.

The advantages of using fly-ash bricks are:

1. Recycling an industrial waste product for a new viable use. Fly-ash otherwise if not properly disposed is responsible for increasing air-pollution, making arable land infertile and contaminating water bodies.

2. Manufacturing of fly-ash bricks does not require firing. Fly-ash bricks are either sun-dried or steam dried. This eliminates the high energy use during the firing of regular bricks.

3. Reduces the need to quarry natural stone.

4. Fly-ash bricks are made locally in Goa about 50 kms. from our project site, reducing the embodied energy used in the transportation of the material to project site.

(Source for some of the above materials is an article written by Tallulah D'Silva on Fly-ash Bricks for Business Goa magazine, April Edition.)

Along, with fly-ash bricks, we have also chosen to use fly-ash cement in construction instead of regular Portland cement. It is not very well known but the production of Portland cement accounts for around 5% of global greenhouse gas (GHGs) emissions. It is estimated that the production of one ton of Portland cement produces about one ton of GHGs. Look out for more details in future posts on our use of fly-ash cement, load bearing walls and filler slabs in our effort to reduce the use of cement and concrete in this building.

Building partition walls with fly-ash bricks

Postcard from High Line exhibition at MoMA that I have saved as a design inspiration since 2005

The High Line Phase 2 opened in June, a few weeks after I flew back to Goa. It makes me sad to not be there and experience it for myself.

I have been tracking the High Line project since 2003 when there was a design competition to transform an abandoned freight railway line in Manhattan into a public park system. The competition was won by Diller Scofidio + Renfro.

In 2005, there was an exhibition at MoMA with a large scale detailed model of the highline that was suspended within the gallery and hung in mid-air. The design and exhibition was so very inspiring for the young architect/ planner in me. I marvelled at the way the architects had proposed a design that preserved the historic legacy of the space, while introducing a new park system that balanced planted green areas along with paved usable spaces.

High Line exhibition at MoMA

I love the contemporary use of material along with new age designs for every element including the precast concrete finger like paving that weaves into the planting beds, the floating street furniture, and special areas for seating and congregation that celebrated the city by framing views and entrances. The relationship to surroundings is further heightened when buildings bridge over the High Line (few older industrial buildings and of course the new Standard Hotel). The entire project represents the brilliance of the architects and embodies their passion for the city, contemporary design and building materials.

The original tracks that were carefully replaced back in their original position after the restoration work

The finger-line pre-cast concrete paving that weaves into the green spaces. Planting beds are planted with native species of grasses and wildflowers so they require less maintenance and water

Floating landscape furniture in new age contemporary design

Amphitheater that looks onto the city streets and celebrates the chaos

Our takeaways from the High Line for our project in Goa are as follows:

- Need for a comprehensive understanding of the site and the project's relevance to its surroundings. Preservation of this understanding and relationship in the proposed design.

- Excellence in design and attention to detail with a passion for perfection

- Integration of contemporary design while preserving the historic legacy of the place

- Fearless new and innovative use of material

- Use of native species of plants to propose a landscape that requires little maintenance, water and other resources

Hotel Standard built over the High Line

My favorite view from the High Line framing a Gehry building and a Jean Nouvel building. 

Click the pictures for a larger view.

Now that our contractor Partner 1, Binod Arya has returned to Goa and we convened a big meeting on-site with the entire team. The idea was to get the construction schedule back on track and develop a new plan for the monsoon that allows us to execute the next tasks in an efficient manner. It was decided that in the main house, the contractor will work on the wood and tile roofs and the internal partition walls next. Then move on to the internal door frames and then the doors for the main openings in the living room followed by the bedrooms. 

What would be the central courtyard in front of the main living room

We also addressed the material shortfall issue. The progress of our pavilion block had suffered severely due to the lack of supply of laterite stone. We dealt with the issue by switching to the use of regular brick to complete the walls of the staff quarters so we can move forward with this block. The next step here would then be to install the roof and then put up the steel structure for the pavilion above.

The pool and deck and beyond

Next, with all the woodwork ahead of us, we addressed the wood issue head-on. We had decided very early on to use as much reclaimed wood as we can in the project. Using reclaimed wood has obvious advantages. One is that we will reuse old wood and not cut new trees for our project. Secondly old wood is actually very well seasoned that reduces the well known problems of wood expanding and contracting with moisture that lead to jamming doors, wood splitting, bending and warping. In my initial discussion on the issue with my contractor, he explained to me that buying old reclaimed wood can cost me more or less the same as new wood and hence it is better for us to use the new wood as I guess for most people new is automatically always better. He went on to give me the example of another project that he is building and explained that ‘Madam - you see this project, we have cut an entire jungle for it’. This was the perfect starting point for my rhetoric on why using reclaiming old wood was important and why we must use it in our project. Contractors actually prefer working with new wood as it is softer and easy to work with. Old wood in comparison has hardened; require meticulous planning for reuse and need to be prepared for new use by shaving off the skin and removing any spoilt sections and nails and other aberrations. But our contractors are very admirable and know their craft well. They are open to and good at implementing new ideas. After a short discussion, they are on-board with the plan.

Mainly in the project, we are using two types of wood – local timber (Matti, Jack) and Burma Teak. We have found vendors that deal with reclaimed Teak in Mumbai. For local timber on the other hand, there is no organized trade that exists in the state. So we resorted to some innovative sourcing techniques. As a result we have been combing through all types of old wood waiting to be found and reused, from packing wood, to doors and windows to wood beams and rafters from old roofs. We are mostly interested in the later. After short listing a few, my architect and I have been cris-crossing the state to look at available wood to judge its quality and reusability. The main criteria is to make sure that the reclaimed wood in not bent, does not have significant termite damage and has not become brittle over time. We think we have found 3-4 sources of good supply. In the next couple of weeks, we will carefully study our requirements vs. the wood that is available and purchase the necessary quantities. More updates on this will follow.

House in Gauses by Anna and Eugeni Bach

A small house in a village in Spain. A featured house in

Architectural Record

.

The architects have employed an open plan while building the structure using traditional construction methods.

Several design themes resonate with our design concept,

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The architects have used load bearing walls to reduce use of structural concrete and steel

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Designed the house so that the corner of the living room opens up to make it a part of the porch and garden while providing views to the mountains beyond

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Used local materials and techniques, like the woven cane for the roof over porch wrapping the house along with contemporary materials like steel frame and aluminium windows.

This is a small house with a very contemporary design that fits right into the surrounding landscape without needing to copy traditional house typologies or making a strong architectural statement. I would identify this as an example of responsive contemporary architecture.

According to an architect friend of mine, 'architecture is nothing but the play of light on surfaces'. This house scores high on that aspect with the beautiful light cane roof creating dynamic patterns on light and shade on house walls that are painted with bright green and white stripes. Everyone, please note that the cane roof needs to be replaced every two years. This material is similar to the way Goans create woven screens from coconut leaves.