We recently crossed another project milestone by completing the first design stage documentation towards the Green Homes certification awarded by the Indian Green Building Council

We are targeting the gold level certification and will be among the first green certified homes in Goa.

Some of Nivim's main green features are listed below. We will try to do detailed write-ups on some of these in future posts.

Trees and preserving site’s unique features

– Our project site had 14 existing trees before construction and we preserved these trees and incorporated them in our design. The design also retains nearly 35-40% of the site as natural landscape. New landscape is planted with majority local species to have minimal need for irrigation water use.

Building orientation and design

– The main house building is oriented with the longer façade facing North-South to minimize direct sun exposure on east and west where the sun is lower increasing heat absorption. Ample shading devices have been planned to further reduce sun exposure and heat intake.

Daylighting and cross ventilation

 – 100% of living spaces are designed to be adequately day lit with ample shading and openings for cross ventilation. This eliminates the need for any artificial lighting or mechanical cooling during the day saving energy use and providing healthy indoor air quality.

Energy

 – 100% use of solar power for water heating. Use of 3-star energy efficient refrigerator (40%less energy use) and 5-star rated air-conditioners (25% less energy use). Use of solar control glass on east and west façade to reduce heat absorption to indoors.

Cool Roof

– 75% of roof is finished with highly reflected material to reflect sun’s heat thus help in maintaining lower temperature in living areas below.

Two openable walls per room provides 100% daylighting and cross ventilation

Water

 – We are collecting 50% of rainwater runoff from the roof and storing it for future use for landscaping and for swimming pool use. Prioritized use of low-flow fixtures in the bathrooms saving 30% of water without having any impact on perceived flow of water and use. We are treating 100% of our grey water* on-site to be used for landscaping thus further reducing pressure on municipal water resources.

* Grey water is all water from bathrooms and kitchen drainage except water from the toilets. Grey water is filtered on-site through a root zone water treatment system.

Permeable paving

– 75% of site’s paved surfaces are built using permeable paving to allow maximum percolation of rain water back into the ground.

Construction Materials

– Use of over 50% building material from within 500kms of the site to reduce embodied energy spent in transporting materials over long distances. Encouraged reuse of salvaged building material as well as building material with high recycled content such as fly-ash bricks, fly-ash cement, recycled tetrapak boards, aluminum and reclaimed wood. Reducing the use of cement** in construction by building load bearing walls and filler slabs. 

**Cement production is known to produce large quantities of greenhouse gases, for every ton of cement produced one ton of GHGs are released in the atmosphere. GHGs are known to be the leading cause for climate change. Read more here.

Low VOC paints

–Use of low VOC external and internal paint to reduce exposure to hazardouschemicals to humans.

List of green certified buildings in India, http://www.igbc.in/site/igbc/certifiedbuilding.jsp

To make up for my silence on the blog for the past few weeks and it being Valentine's day and all, I offer you all some exciting pictures from the site that is now in it's finishing stage.

The pictures show the house with some woodwork already up and more on the way. It also shows the pool ready for tiling, deck ready for decking and gardens ready for planting ! Hope you ENJOY them as much as I did !!

The following pictures show the sequence of spacial experiences in the living room:

Living room exterior with the front courtyard with existing trees and most of our amazing team (In front, Contractor Binod Arya and Site Supervisor Manoj Shetgaonkar)

The interior of the living room from the back wall, showing the staircase frame, play of light through the louvered opening, front courtyard with existing trees, the pool, deck and gardens, and the hills beyond.

Part of the front elevation

Partial view of the house with the pool and gardens in the foreground. All the area on the right in the picture will be a planted lawn with a row of trees along the boundary wall.

Detail of the living room with the louvers, exposed basalt wall, monumental room height and the tall existing trees.

15,000 miles in 4 weeks

In the last week, I have been to Singapore, attended a wedding in Mumbai, a funeral in Ajmer (Rajasthan) and entertained friends in Goa. If I include three more weeks then I have also been through New York, Germany and Delhi. While I was traveling some 15,000 miles across 3 continents, 4 countries and 10 cities, my team back in Goa were continuing their efforts to move along the design and construction on-site. Thanks to the "flat world" brought to us by information technology, I was able to run my job-site seamlessly amid all the travels. We continued our project meetings through Skype and construction monitoring through bi-weekly digital photography.

What got left behind were my regular construction blog posts and I hope to make up for it in the coming weeks.

I like this photo a lot as it shows how the fully built structure of the house is completely hidden by the exiting foliage on site. The pool pavilion structure on the left is designed as a light structure built completely in wood and steel.

Here is an update@ week 45? There has been good progress and have completed the steel framing for all the openings and the wood rafters for the sloping wood and tile roofs (above LHS guest bedroom and master bedroom). In addition to this we now have a large team of carpenters who are busy preparing lovely teak wood for the fixed louvers and sliding doors.

Pool pavilion as seen from the living room in the main house

The pavilion block is shaping up really well too and the steel frame structure is almost completed. This structure will then be topped by wood rafters and then a sloping roof membrane.

All this while, the electrical points, plumbing and waterproofing is also being carried out. The site in general is buzzing with activity with civil work, woodwork, electrical and plumbing all happening simultaneously.

Fruiting Tamarind tree on-site

The weather in Goa has already turned to it's annual best. Winter weather in Goa can be compared with Spring or early Fall weather in New York. One is treated each morning by a clear blue sky, light filtered sun that makes everything shine and a cool soft breeze. This is a time when we can now conduct our project meetings on-site at the deck area offering a glimpse to the glorious moments the house will present once it is ready for use.

Tamarinds from our tree ! 

In other news, the tamarind trees on site are fruiting and there are countless tamarinds on-site. We have 2 full grown tamarind trees on-site. There is also a tree on-site that gives a fruit called Tehfa. This fruits smell and look like tiny lemons first and then breaks open to produce black peppercorn like seeds. The fruit is used specially to cook a special Goan Mackerel curry. The one tree on-site has enough fruit to feed curry to the entire village!

The framing is going up for the skin of our extra large 11 meter wide living room openings.

View of the entrance courtyard, part of deck and pool pavilion

We have a small milestone to celebrate this week. We are completing 32 weeks into construction at our project site. With a projected total of 12-14 months as our construction timeline, we are close to the 60% milestone. The real reason to celebrate is that we have completed 60% of construction on-site and are almost on-track to finish within our projected schedule. For anyone who has built in India, this is quite a considerable feat. Projects in India are ridden with unexpected and often unexplained delays mainly due to the unorganized construction industry, loose legal frameworks and maybe skewed priorities among builders and contractors. While design is all glamorous and intellectual, the construction process is where one needs to get down and dirty with all kinds of details of sourcing the right materials, controlling quality on-site, meeting deadlines and coordinating with the various professionals involved. Our team deserves a lot of credit, they are working hard and have a common unique trait (that is central to our hiring process but sadly not that easy to find), they all "take pride in their work".

Last month, we had the privilege of a visit from two prominent architects from Delhi to our site. They left with two comments. First - "Finishing a project in India in 12 months is only possible if it is regular building, it is very difficult to finish a project in that time while building the way you are building". I guess they were referring to our load bearing stone wall structure that require much longer to build than a typical concrete structure, plus the large size of our rooms with high ceilings and possibly to the fact that we have very large openings and not little pigeon hole windows and doors. Their second comment was, "If the talent exists then how come we do not see buildings in Goa built in even half as conscientious manner as you are building." This is the best compliment we have received so far and I was joyous to hear this observation.

At our 60% milestone, we have completed nearly 90% of our civil works, electrical and internal plaster. Civil works for external landscaping is almost 50% complete. We are now busying ourselves with the internal and external door frames, plumbing and flooring.

Sketch rendering of our elevations and opening design

Since, we keep talking about our extra large openings, it is clearly evident that they are critical to our design proposition. We have gone back to our drawing boards many times in order to perfect the design of the fixed and movable doors and windows. The final design looks like the rendering above. All openings will comprise of fixed glass windows on top with wood louvers and movable sliding door panels below. The movable panels will all have a fixed shutter on one corner with wood louvers. All the remaining sliding doors when opened will stack behind this fixed frame. The louvers are designed such that they provide an interesting play of light and shadow within the room at different times of day. Louvers reduce direct sunlight and glare into the rooms. On the other hand, louvers also reduce the visibility to the outside. Keeping this in mind, the openings have been carefully designed with a balance of louvered panels and ones with clear glass.

Sample of a fixed louvered section of the opening built on-site for review

Another interesting functional design feature in our external opening design is that the fixed louver panels will actually be fitted with mosquito nets and have a sliding glass door behind them. This is our proposed solution after various design iterations to address the following conflicting factors that influence living in Goa:

- the ability to keep the doors open for as long as one can to connect with nature

- the insurgence of mosquitoes at dusk specially during monsoons

- the ability to allow for cross ventilation at all times of day even when there are mosquitoes, or if it is raining, or for any other reason the doors need to be kept closed

- the need to make the space air-tight if the use of mechanical air-conditioning is needed

Attention to details such as this comes only from living in a place through the seasons to know peculiarities in climate and livability. Trust me, I wish I had mosquito nets in the openings in my house that allowed cross ventilation, did not block my view, were easy to clean, not stuck with velcro, did not obstruct my ability to open and close my windows and most importantly kept the mosquitoes out but the breeze in.

Another key success of adding nets to the openings is enabling cross ventilation at all times and reducing the need for mechanical air-conditioning at all times of the day throughout the year. This reduces the energy requirement of the house and the pressure of added development on the land.

As a result of our opening design, 100% of our living spaces are daylit. This is based on the math that shows that 100% of our living area has a daylight factor of at least 2%. (Daylight Factor = Window Area/ Floor Area X Actual Visible Transmittance X Constant)

In addition, 100% of our living spaces have access to fresh air ventilation. This calculation is based on the area of openable windows as a proportion of the living area of each room.

Both these statistics far exceed the standards for Indoor Air Quality as mandated by leading green guidelines as being critical to healthy living.

So far so good. looking forward to more happy discoveries and experiments in the remaining 40%. 

Outdoor space at Villa Aashyana in Candolim in Goa

Last week began as an exciting week. We issued the landscaping drawings and began work outside. Miraculously this year the monsoons have pretty much subsided by the beginning of August. Even though this means that the temperature is rising (and I never want to say goodbye to the lovely monsoons), this is good news for our construction crew who can now work outdoors.

This week, we built the verandahs that wrap around the bedrooms and designated courtyard spaces for the bathrooms. As I have mentioned before, in our design concept, we have designed each bedroom to be like an individual pavilion that sits within its own series of open spaces. The ground floor bedrooms are wrapped around by covered verandahs. These verandahs are designed to be an intermediate layer that connects the indoors with the outdoors. The covered verandahs and balconies are designed to be the extend the bedrooms outdoors.

For our project, the outdoors are as important as the indoors.

The core design concept is to design a house that allows one to ‘reconnect with nature’. In response, all our indoor spaces are designed to have a progression of open spaces that maximize interaction between the indoor and outdoor. First, each indoor space is designed with two out of four walls that completely open to the outdoors. These openings then connect the indoor spaces with the covered outdoor vernadahs and balconies. These intermediate spaces then connect to the central deck space and surrounding gardens. The garden spaces are significant as this house sits on a large 1000 sq.m. land parcel. In our design, we have tried to minimize hard space. Over 40% of the site has been preserved as natural landscape. This does not include the driveway, parking and parts of the deck that have been designed with permeable paving.

(On a side note, permeable paving allows rainwater to percolate back into earth. Hard paving creates non-permeable surfaces that increases the storm water run-off from land, which in turn reduces percolation back into earth thus reducing the recharge of underground aquifers and potentially overloading the storm water run-off drainage system in the area)

Sketch showing the west-side bedroom designed like a pavilion with two walls out of four being large openable wood and glass doors.

View from the inside of ground floor east-side bedroom to the outside minus the pile of debris. The two openings will have sliding wood and glass panels that leads to a wrap around covered verandah

According to Geoffery Bawa, ‘life in the tropics is about living outdoors’. Along with the living spaces in the house, the bathrooms are also designed to connect seamlessly with the outdoors. One full wall in each bathroom is designed to be built with openable glass. This transparent glass wall and opening will lead each bathroom to a dedicated courtyard space. The courtyard spaces are designed to be more than just little outdoor showers tucked away in the backyard. The bathroom courtyards are carefully designed around existing trees. They are spacious garden spaces that are designed to be private escapes possibly with relaxing arm chairs, day beds, maybe a hammock, a bird bath or two and of course the outdoor shower and bath..

This space will be the master bathroom with a picture window above the wash basin counter and a terrace with a built-in outdoor bath-tub.

The reason for this mad chase behind the indoor-outdoor space concept lies in the fact that we are building in Goa. It is common sense that building construction in Goa should be different from building in urban cities in India or coastal areas around the world. Reconnecting with nature is central to one’s choice to live in Goa and it is a luxury few can afford. This makes it essential to pay special emphasis to the relationship between the indoor-outdoor while building that dream country home in the beautiful tropical paradise of Goa.

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.

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

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.