Monthly Archives: March 2016

Stone for a roof

Using stone could reduce resource consumption in the construction sector.

26bgp-greensens_26_2789187gHuman civilisation is an ever optimistic one, with a ‘never say die’ attitude. It is this undiluted trust in us that makes many people possibly believe that the current crisis of climate change can be controlled across time. They may quote many instances from the indomitable human spiritto illustrate how someday we will reach our goal of reversing the climate crisis.

However, we appear to be relying upon ideas rooted in the same technology or innovativeness, which in the first place created the crisis, to solve the crisis. This is not to demean new research, but to suggest that we also need to relook at the past to look for possible solutions. After all, days of the past did not lead to excessive consumption or climate crisis. Hence, they may offer some sober and steady ideas, however few they may be.

Using stone slab as a roofing material can be an illustrative case. Stone roofs have been popular across India. Slabs were cut into pieces two to three ft. wide and up to 12 ft. in length, depending upon the strength of the material. Stone or brick pillars were erected, upon which stone or wooden beams rested, and they were topped with stone slabs, joints finished with water proofing.

The very mention of this system would make experts in modern construction consider it as primitive. It cannot be used for making modern multi-storey office complexes nor could it be economical given the time constraint we face in projects. The present rate of urbanisation would deplete the local supply in no time.

Right solution

Many such arguments can follow to delist the option for ever, unfortunately forgetting that stone roofs can be a solution in a few appropriate contexts. Today we need hundreds of such solutions to collectively reduce the massive concretisation of the construction industry. With cement and steel dominating all major items of works in every building, from foundation to water proofing, from floors to wall finish, it is imperative that we introduce a few items where we can minimise such manufactured materials.

What is strange is the way we forget our present practices and lifestyle the moment a new option is on the horizon. Why cannot a known solution co-exist with a new, innovated one? Why discard proven design and construction possibilities, when they continue to have logical and practical applications?

This is not an argument just to support stone structures, but to support thousands of such small, appropriate and sustainable ideas that could reduce resource consumption.

Green power, officially

The cumulative effects of changing the way government builds can have a lasting impact on the country’s carbon footprint.

downloadWho is the biggest builder in India? The government, obviously. From huge infrastructure to humble homes – there is nothing left out by the government in its spree of construction activities. All these building activities are with public interest, even when a building use is restricted for few users or houses allotted to people who buy it outright. Can we imagine nationwide government buildings being eco-friendly and green?

Much has happened during the last decade to bring the green design agenda into public architecture, including the efforts of BEE (Bureau of Energy Efficiency) and TERI, which insist on green building ratings for public buildings. If every construction starting from village panchayats to urban facilities can be designed as eco-friendly architecture, in a single stroke we can reduce the carbon footprint and energy consumption of our nation. This may also have a positive impact on the way private sector builds in the given village or town, ushering a design revolution in the country.

Good example

Indira Awas Yojana could be a good example to illustrate this point. It has been among the longest running public housing programme with over 25,00,000 units built till date. Besides, there are housing boards, slum redevelopment schemes, State schemes such as Ashraya in Karnataka and many others. Finances have come from budgetary allocations, and from institutions such as HUDCO. Everyone thinks they are one- or two-room tenements, hence need not be considered for special thoughts of the eco-kind.

Majority are built within the knowledge limits of the local contractor following the schedule of rates fixed by the government. These specifications are rooted in standardisation, rejecting local best practices; as such not only end up costing more but often become an eyesore in the village.

The beneficiaries do not question since they get it free, the contractors do not bother if they get their profits, the officials are more keen to ensure funds are spent within the financial year and so on.

Finally the opportunity to elevate such mediocre looking sheet-roofed shed-like shelters into houses with better aesthetics, local fit and appropriate to climate is lost forever.

For a lasting impact

As single structures, houses appear vey small, but running into many lakhs every year, this is a major construction activity. They can ensure houses are culturally and contextually appropriate, ensure continuity of crafts, retain local economy and provide training for skill-sets of doing good houses. Just like housing, there are many other sectors where the government constructs thousands of buildings. The cumulative effects of changing the way government builds can have a lasting impact on Indian carbon footprint.

Single material, multiple benefits

Rhythmic repetition of a material in construction creates a harmony that cannot be achieved by using a dozen materials together.

12bgp-greensens_12_2771445e.jpgWe are living today in an era of millions of options and multiple materials – thousands of choices, hundreds of colours, dozens of technologies and no two buildings or interiors looking alike. If this is a commendable achievement of our generation, imagine how dull and boring the past could have been?

Our forefathers must have been dissatisfied with their food, clothes, travel and homes. They must have been inefficient and unhappy with their limited design choices, few building materials and very basic construction technologies. Lack of innovative ideas must have forced them to lead a life with imperfections and adjustments.

Or, are we wrong in assuming so? Is it possible that lack of choices might have led them to perfect their known materials and technology? Could centuries of stylistic development have led to millions of regional aesthetics that we cannot even comprehend today, leave alone recreate such richness? Can we grudgingly admit to self-introspection to see what is better – innovations of today with all the imperfectness they have come with or perfections of yesteryear achieved through time, tested, studied and repeated across centuries?

Evidently, the answer does not lie in either but in a case-by-case evaluation for blending and applying traditional wisdom with modern thoughts. Unfortunately architectural education and civil engineering degree course prepares us mainly for ever changing modern ideas. Naturally, the theory of design and history of our architecture are irreversibly relegated to the backseat. Of course, then we justify our choice of modern thoughts by quoting  global trends, market demands and client needs.

Let us look at the idea of single  material as an illustration. Temples of Bhubaneshwar, bungalows of Bengaluru, monasteries of Ladakh or building types of Tamil Nadu temple towns lacked varieties in material or style. Most often they used just a few materials and their visual attraction can be attributed to the rhythmic repetition of same material, creating a harmony that cannot be achieved by using a dozen materials together. In total contrast, mixing many materials to create a hybrid and cluttered appearance has come to stay as a trend today.

Ecological sense

Single-material approach makes tremendous ecological sense. Every region can claim only a few local materials to be the best fit for its climatic context, suggesting that other materials should be avoided. Being variation of the same, be it stone, bricks, mud, bamboo or any other, there will be least wastage, for the material left out after one kind of usage can be employed for another purpose. Probably, passive cooling, lowered life cycle costs and maintenance matters are better addressed by these few choices. Can there be better green buildings than these?

Even today, conscious architects are applying single or very few materials’ concept as an approach to ecologically sensitive architecture. This can counter the image conscious, photogenic, visually loaded and stylistically hybrid architecture, which gains popularity merely being provocative to the senses.

Rammed earth on the roof

There is no dearth of ideas in construction, only of implementation.

05bgp-greensens_05_2762866eHow many materials may we find in a typical urban home today from foundation to parapet walls, leaving out the interior finish? It could be half-a-dozen at the least, thanks to the manufacturing and supply chain. However, in the past, buildings would have had fewer materials, often with single material like the complete wood houses in Meghalaya, all stone houses of lower Himalayas or mud houses of Rajasthan.

Single material as an approach to building has been a major theory of architecture; as such, Taj Mahal in Agra or havelis in Jaisalmer are not freak cases, but specifically designed to evoke public perception, meaning and image. Today we mix and match everything available, creating hybrid designs never seen before, creating an urban aesthetics which can be debatable.

We may reason the architecture of the past to limited opportunities, and praise current times for multiple materials available, each appropriate in its context of use. However, multiplying options has also led to increased consumption, energy use and wastage, demanding a more greener living today. From the sustainability perspective, it makes sense to relook at the past practice where people lived with the materials they could get in their locale.

Rammed earth in roofs can be cited as an example, where stabilised soil cement block or rammed earth walls are already a part of the building. Having proved the benefits of mud in the making of the wall, organisations such as Hunnarshala at Kutch and Gram Vidya in Bangalore tried it out like a flat slab. After all, the wall can be visualised as a slab kept vertical and if so, these slabs can be kept horizontal also as floor or roof.

Reinforcement

Domes and vaults in mud have proved to be stable, but flat slabs would need means of strengthening them, being weak in tension. Hence, nominal wire mesh reinforcement is placed during ramming. Besides, larger the dimension the weaker could be the slab, hence a safe size of 2 x 2 ft. has been adapted. These slabs were initially produced under lab conditions and only after testing, were applied to construction sites. As such, it needs engineering inputs and technical supervision before any site implementation.

For floors, the rammed earth slabs can be simply placed on a hard sub-floor, to be top finished as desired. In case of roofs, pre-cast concrete beams can be placed at two ft. spans to support the slabs on top, just the way stone slabs and wooden rafters were used in the past. Nominal roof concrete with minimal reinforcement can be cast atop the slabs to get a homogenous floor with choice of flooring or water-proofing layer if it’s the final terrace. The bottom of the roof can be left exposed to showcase mud or painted to emulate the looks of a false ceiling.

It’s often said that there is no dearth of ideas around, only of implementation. Rammed earth proves this point beyond doubt.