Blog Archives

Think before replacing

We demolish old buildings even when they are in good condition for the sake of bigger and better structures. But is this justified?

01bgp-greensensG2520RDPN4jpgjpgWhat’s the talk of the town in the lighting sector now? It is replacing old bulbs with LED fixtures in existing buildings. Thanks to government schemes, millions of tube lights, CFLs and incandescent bulbs have been replaced, to save electricity, which is a laudable project.

So too, we have been replacing millions of cell phones, laptops, television sets, washing machines, air conditioners and other gadgets to keep pace with technological upgradation. What about buying a new vehicle every five years? Not a bad idea because maintenance costs go up after few years of driving and anyway there are buyers for used cars. Exchange offers are very attractive, and we feel good about the increased speed, storage and comforts.

Contrastingly, if we think of the past, how often the tube light got changed; house landline phone replaced; new wall clock bought; ceiling fan disposed or any such other household item was exchanged, we realise a major shift in our lifestyle – a lifestyle which embraces products in the name of advantages. Do we compare electricity saved with embodied energy to nature and monetary cost to individual to check if the replacement was judicious?

Thoughtless replacement?

Thoughtless replacement is not ecologically advantageous on all occasions. We rarely bother about where the disposed item goes and whether it gets responsibly recycled without leftover waste.

Even if we care, what about the additional production we are supporting by buying a new product? What about the resources it is consuming, waste it generates, fossil fuel for transportation and marketing energy?

The tragedy is that we are replacing products while they are still functional with many more years of working life left; unlike in the past when the new entered only when the old became dysfunctional and exited.

Majority of us use fairly recent mobile phones today, which could be the third or sixth one since we purchased our first mobile, say a decade ago. It is a financial burden, but we justify it saying we can afford the cost. The old ones could perform, but we justify claiming the need for updating.

Old buildings are still good, but we demolish them seeking a bigger and better building. But can we justify the ecological cost of replacing, a burden not directly on us, but on the Earth? Can the money we have that buys a new phone solve the problem of the disposed old one? With our own body, do we try to extend our working life as we age or simply stop functioning, letting the new and young take over?

Replacing is required, but not unless the utility of the old product is over. Green living does not revolve around switching over to the latest, every time a new product introduction happens. It revolves around utilising what we have fully, until the end of its functional life.

Advertisements

Let sunlight in through a tube

It can be a wonder solution to our crowded city homes that can help cut down on electricity bills.

14bgp-greensens_14_2852317g

The tubelight still lights up many homes and many elders continue to love it though its era is over, replaced by CFL and now LED bulbs. But should we believe that it has staged a comeback? Yes, not as electric lights, but as tubes that bring in natural sunlight through the wall or roof.

All this goes to prove the human need for sunlight and our desperate attempts to get it into our own creation of dark interiors. Much has already been written about the health benefits of sun light. Yet, why are we designing deeply enclosed and dark places in the first place? Even in the discussions around green buildings, there is much importance to the daylight factor, though it is often achieved through technically advanced, hence costlier glass-based solutions. Possibly, concerns of this kind must have led designers to evolve simpler, alternative ideas to divert outdoor light into the indoors.

Simply stated, the light tube is a pipe with transparent sheet at its mouth and highly reflective paint on the inner surface which transfers sunlight into a room. At the advanced level, we can also have panel precision cut through lasers, solar reflectors that face sun’s direction, reflective mirrors and such others. As a modern product, we get to see one at Forgotten Food Restaurant at Hasiru Thota in Bengaluru. However, the idea itself is an age-old experiment in forts and palaces of India, tried through narrow tube-like voids within the wall.

Light tubes open skywards and not sideways, hence can capture light for longer hours. Unlike in a window, there is no loss of privacy; unlike the skylight glass, it needs no cleaning and has no life cycle cost at all. The collector at the beginning and diffuser at the end are the major fitments which effect intensity of light, beside the inside finish. Shorter the length and fewer the bends, in principle, should be the way to design them.

Light tubes offer no glare and no direct sunlight that can affect our activities. By using appropriate materials, one can reduce infrared and ultraviolet waves which can result in reducing indoor heat, a frequent problem associated with light. The road elevation and indoor appearance may be mistaken for some industrial exhaust system; as such the aesthetic attraction of these tubes are subjective, hence may have to be located judiciously.

We are yet to have many manufacturers of the light tube, though it can be a wonder solution to our crowded city homes. Making one each for a home may not be economical; large-scale production of modular sizes being the only way to popularise it.

If we can not be eco-friendly in our daylight design, we can still enjoy a green home using light tubes.

Light from the roof

Many offices and rural homes are considering installing photovoltaic panels to supplement their grid power supply.

22bgh-solar-gre_22_1802904e (1)What is the buzz word today in the world of renewable energy? Without much thinking, everyone will say solar energy, a rapidly expanding technology with unlimited potential. While many buildings are already getting their power supply largely from solar power systems, many more from offices with backup diesel generators to rural homes facing frequent power cuts are considering photovoltaic panels to supplement their grid power supply. We can see a future unfurling.

It all starts with the basic home lighting systems to generate 250 v to 3,500 v with CFL or LED bulbs ranging in number between one and 10. There would be a PV or photovoltaic panel, also called as the module, made up of crystalline cells capable of converting solar light into electricity power; battery; charge controller to monitor overcharging; and the cables.

Depending upon the budget and location, one may buy the bulbs in numbers as required. The DC power generated here does not become part of the house wiring, but directly feeds into the bulbs as located.

More advanced technology with greater power generation options lies in roof top systems. Besides the PV panels, battery, charge controller and cables, they additionally have an inverter or hybrid UPS system, which enables DC to AC conversion and battery charging both by solar power and electricity grid. The panels are fixed at 15 degrees slope to south, normally mounted on steel supports at any reasonable height as per site condition. Panels come in 1m x 2m size, producing average 250 watt power. To generate 1 Kw we would need four panels and 2×4 m space. While 1 Kw suffices for most small homes, it is limited to lights, fans and such other non-power circuits. Increasingly families are installing up to 5 Kw to turn the house into completely solar powered.

Accessibility

Panels need to be fixed on the flat terrace, but can also jet out as a projection from the wall, be on the top of a sloping roof or create a pavilion roof of its own. However, accessibility for proper installation and maintenance is a priority. Every panel should ideally come with one battery to be able to save all the power generated, though some vendors may suggest fewer batteries to save on upfront costs, which is not an optimal solution.

Making solar cells, which finally make the panel, involves high technology with only four companies doing it in India. Despite the panels having marginal annual power degradation ranging from one to two per cent, they easily last for 20 years or so. Nowadays many cheaper components are being imported, which may or may not be value for money, so it is safer to check the source before buying.

As the building construction approaches the end, owners left with little money tend to re-think on installing solar power. It is a valid thought, but in long term installing solar power will be a wise action.

Why jazz up the bathroom?

Good daylight and air flow, skid-free flooring, ease of maintenance, and proper lighting in a bathroom can be achieved without spending much money.

16marchIf we count the number of pages with advertisements in any design journal today, which product range hogs the limelight? For those who have not counted such pages, here is the answer – it is possibly for the products needed in bathrooms, toilets, and wash rooms.

We are discussing something private and personal — the bathrooms.

It feels strange to discuss it in a public forum, but the new trend of spending or to say it more bluntly, wasting resources on the bathroom and toilet has assumed such proportions that it needs to be relooked at.

There are many projects where cost-effective and ecologically sensitive ideas have saved money and resources, only to be drained out through luxurious bathrooms.

The manufacturers and the market together have created such a glorious image for the bathroom, which is also a room of course, that most of us are caught in this trap of spending on it without realising the implications.

Soaring prices

Once there was a time when the costliest western commode, also called as the water closet, could be bought at Rs. 5,000, but today we can easily shell out more than Rs. 50,000 for it. Water taps could be bought at Rs. 10,000, glazed tiles for wall dado can be picked up at Rs. 500 per sq. ft and this list can go on.

The tragedy is that most of these high-end products costing 10 times more than the low price range items are really not 10 times more superior or more comfortable or more durable.

If so, how did this trend of resource consumption evolve? Why do people proudly say that the bathroom is their space and would spare anything to get it their way? How did the habit of conspicuous consumption move from a publicly visible part of the house to a privately usable area?

The answer

The answers could lie in some sociological analysis, but from the construction industry perspective, part answer lies in consumerism and affordability.

It is believed that a fancy idea sells faster than a common sense one, thanks to the glorified image of the former.

The idea of luxury in bathroom can be achieved without taxing nature — by creating space and letting nature in. While the up- market fixtures may help in certain quality issues, the primary criteria of a bathroom lies in hygiene. To that end, good daylight and frequent air flow to ensure quick drying of the space are necessary.

While the market is selling costlier ideas to impact the looks of an attached toilet, let us realise that the experience of a toilet does not depend only on fixtures and tiles. Skid-free flooring, ease of maintenance, proper lighting even at night and all such issues are imminent for a comfortable bathroom.

Most of these can be achieved without much money and materials.

For thermal comfort

Knowing daylight and shadow patterns round the year is helpful, and common sense observation can be the starting point for understanding light and shade balance in buildings.

Often we see design ideas going through a paradigm shift, nearly to the opposite ends. To realise this phenomena, look at this — from the past practice of building for shade inside the jan5house and outside on the walls, today we are seeing buildings washed with light everywhere. Accordingly, windows on the walls have become larger, external walls are exposed to direct sunlight and skylights have been introduced.

While the theory of light is desirable, the resultant heat built-up is a nuisance no one can live with, hence the need for ideas to shade the building. From an eco-friendly perspective, the more shaded the building, the more cool would be the inside space. In case of air-conditioned structures, this would reduce energy needs; and if not, we achieve more effective passive cooling.

Emergence of chajjas

During the early years of modern architecture in India, simple projected chajjas were introduced. Most people think they are mainly for rain, which is not true. As shading devices, though without specific considerations of direction, depth of projection and materiality, they continue to be popular in India.

Thinking architects like Le Corbusier experimented with alternative forms, and came out with specially inclined concrete walls outside the window, often called as Brise Soleil. Much before him, the Golconda building at Pondicherry had a series of horizontal concrete fins. Such external skins placed closely to the walls allow wind movement and let in diffused light from the bright tropical sun but prevent direct solar radiation into indoor spaces.

Indian traditional designs did not use an external skin, but provided deep overhangs like at Fatehpur Sikri or built external walls as perforated jaalis to reduce heat built-up as found in Jaisalmer. Or positioned wooden louver-based features as walls as seen in the Padmanabhapuram Palace. Of course these are among the best examples we get, with thousands of variations with lesser effect commonly found all over our country.

Solar charts

While all the above measures are valid and much needed, our data base for ensuring shade has drastically improved over the years. For every region now there are solar charts – specifically locating the sun in technical terms like altitude and azimuth for any given minute of the year.

It is possible today to calculate the exact pattern of shade for any given time using manual formulae or computer simulated software driven programmes. These measures assist in designing the shading device to derive increased shade in summer and increased sunlight penetration in winter. India being in the southern hemisphere with high summer sun and low winter sun is a difficult place to design for, considering our vast geographical extent and regional diversities.

No single solution can serve year-round needs; hence we need to think judiciously to derive maximum benefits across the seasons. While computer software can help, common sense observation and following the right kind of precedence can be the starting point towards a building where light and shade are balanced.

Design with the sun in mind

The building plan must work with the sunlight, and locate spaces accordingly.

29bgpgreensense_29_1314171eRecently the Jantar Mantar, a solar and astronomical observatory at Jaipur built by Sawai Man Singh, made news by getting into the UNESCO World Heritage Sites list. Many parts of the ancient world boast of historic structures designed to calculate climatic data, wherein the sun dial finds a place. Even today, some science students prepare sun dials for annual school exhibitions. The elderly in a village predict the time of the day nearly correct without any wrist watch. Local and vernacular houses never opened a window to certain directions, and where possible the village streets followed specific orientations to ensure that the majority of houses faced fewer directions.

We are discussing a traditional knowledge system, centred around the Sun – a system which resulted in mind-boggling applications ranging from rituals to rhythms; cosmic studies to cultivation; design matters to social philosophy. There are many temples where sunlight is brought into the core of the structure on certain days of the year, calculated so precisely hundreds of years ago. People realised how to understand sunlight, and invite it or avoid it accordingly. With no mechanical or artificial modes, they evolved shelters which stayed cool during summers and warm during winters.

Well, the point here is not to simply praise our past, but to wonder where we have lost that knowledge. With a wealth of buildings behind us, why are we building such that we get roasted inside during the summers? The answer is simple – we have ignored designing with the Sun.

India being a tropical country gets a great share of sunlight, which can be directed judiciously into the building to get all the daylight we require. Nowadays there are many computer softwares like ‘ecotect’ that advice about sunlights and shades, while in the past there were climatic data tables with sun chart diagrams and solar angles. One can apply the simple formulae using the solar positions called as altitudes and azimuths to know the direct solar incidence on a window. According to such computerised or manual calculations, one can decide the location and type of shading required.

Our elders have already researched about summer solstice of June 21 and winter solstice of December 21 to enumerate how one fixed window or shading device does not work best round the year. As such the challenge is to ensure the building plan works with the sunlight, i.e. locating spaces accordingly. Rooms requiring light face the solar directions, while those which need less light are kept away. Also, rooms that can block the heat gain are placed to cut the unwanted solar light.

However, planning alone cannot provide all solutions of letting in light without heat. Shading becomes an essential mode of designing for sunlight, a mode that demands more of our attention.

Tackling sunlight

Eco-friendly architecture and green buildings depend largely on elevation design, and specifically window design.

22bgIt is a paradox. Without consumption of sunlight we cannot live; equally well, without protection from sunlight we cannot live. In a modern context, this apparent contradiction needs to be resolved by the design of windows, hence eco-friendly architecture and green buildings depend largely upon the elevation design in general, also called as façade treatment, and specifically window design.

Three parameters

If we search for the essentials of architecture as shelter making, we end with up three parameters. Shelter from heavy rain, protection from cold wind and shade from harsh sunlight. The first is served by the roof; the second by the walls; and the last by both roof and walls. Of course it would be a dark box if only roof and walls exist. As such, to let the required air and light, windows were installed by the early human settlers. They were small, being built into the building volume, hence naturally protected. Contrastingly, today windows are large, placed at the open edge of the wall, exposed to vagaries of nature, demanding adequate measures not to let rain in and stop direct sun into the building.

The chajja

Traditionally, most regions of India did not have the projection, nowadays called as concrete chajja. The sloping roof overhang was so deep, it would cover up the wall and window opening. Alternately, there would be a wooden bracket supporting the sloping sunshade over the windows. In case of flat roofs in hot arid regions, small stone slabs or sometimes an ornate window design as a box can be seen. The formal concrete slab projection as chajja appears to be a post-independence phenomena, further popularised by PWD norms. Irrespective of cardinal directions, sun movement patterns, degree of shading required, type of building or any such criteria, we have been adding this concrete slab over the window everywhere. Most often, we do not know how effective this shading device has been.

Incidentally, in dense urban housing areas, the chajja may also do more harm than benefit. With neighbouring building standing tall, the whole wall of a building can be shaded, ruling out the need of chajja shades. With narrow setbacks between two houses where no direct sunlight reaches the windows, the chajja would further reduce the incoming indirect light, making the houses darker. When a chajja faces the direct sun, the air around it heats up, which trends to enter the house, increasing the interior heat gain. There have been numerous cases where chajja becomes a point of water ingress.

All these above notes are not to negate the need for chajja; they are also needed for stopping rain, add elevation attraction or protect the wall from rain water flow along the surface.

The point is about designing studied and properly reasoned solutions for shading a building, without losing out on indoor light or air. Incidentally, all such climate responsive buildings have also to be attractive and culturally appropriate.

Capture the rays indoors

Jaali skylight can replace clear or translucent glass, thereby reducing the quantity of light and controlling the daylight factor.

Delightful: When sunlight filters in…

Have we ever walked under temporary roofs done with interwoven coconut tree leaves? In rural areas they are a common sight, especially during weddings, festivals, public congregations and such others.

Sun rays filtering through the voids of the leaves, moving across the hall as the sun moves in the sky, and creating a playful interior is a delightful experience to bask under. If designing can source inspiration from nature, such enclosures created with natural materials can also be an inspiration.

Jaali blocks

There are a variety of jaali blocks, bricks with hollow voids, available in the market. They are placed within mild steel framework, fabricated to the size required, with mortar packing in the joints from above. Depending upon the area to be covered, the structural design of M.S. frame may get cross beams and edge beams, but the top of all purlin-like horizontal members should be at the same level to take the blocks. The steel and block junction needs to be water-proofed, to stop water penetration there which may rust the members.

In case minimum light is desired, half of hollow clay block can be used, though it is not a light weight solution. The regular clay jaali blocks are only 2 to 3 inches thick, making their use the most ideal. Inverted T sections are the best, though angles and flats can also be used in various combinations. The top surface can be topped with glass, where the fabrication can be done to a gentle slope, to avoid rainwater falling inside.

Perforated roofs can give a miraculous touch to the internal skylights and courtyard roofs. While light gets in, it can happen so only through the voids, hence the interiors get a soft touch.

Especially where a single piece of glass is not desirable due to quantity of light, jaali skylight can replace clear or even translucent glass, thereby reducing the quantity of light and controlling the daylight factor.

In case the block size appears large and feels insecure, additional mild steel guard bar rods can be welded into the roof support, creating the window grill type of fabrication, to increase the sense of security.

The jaali roof has a great advantage in being a light weight solution. In case a rooftop enclosure is desired where weight restriction limits our options, jaali roof is a safe choice. If rain can be let in, the roof need not be topped with glass, making the overall roof still lighter.

For air, light, rain…

Jaali roof is a slab for all practical purposes, but can let in all the three – air, light and rain! Hence, it is best suited for outdoor purposes, where there is no further upper floor. Being an assemblage of structural steel and blocks, it is not at all cumbersome like the RCC slab. The aesthetics, ease of assembly and maintenance together make the perforated jaali roof a choice for many occasions.

Avoid narrow passages

Why stick to staid approaches? If we fail to connect two rooms efficiently, why do we simply introduce a passage in between?

Simple concept: Open planning liberates spaces

It’s strange but true: functional efficiency, cost-effectiveness and eco-friendliness are connected. Most ideas and systems we have been discussing, like passive cooling, local materials, tall windows, verandahs or skylights, together exhibit all of the above qualities.

These could be contrasted with other ideas singularly effective, like a sound-proof window or RCC chajja, which may cost more or have average climatic performance. Most often, consultants are aware of the limitations of these ideas, yet end up executing them mostly with no other choice in sight.

However, there are approaches simply taken for granted, only to be repeated without critical thinking. Narrow internal passages are a case in point. These are among the neglected parts of the plan making process, where if we fail to connect two rooms efficiently, we simply introduce a passage in between.

This is a trap

Movement is an activity that happens all over the building, since we need to reach up to every inch of the plan. While all areas accommodate one or the other activity, the 3 to 4 ft. wide passages serve only movement, walking across into some room or door. Where every inch of built area is increasingly costly today, why are we into this trap called passages?

In cold countries, passages served a climatic function – they acted as buffer zones, helping so much in retaining the warmer room temperatures. Most rooms were fully enclosed with thick walls and doors, to be shut off from the vagaries of harsh nature.
Thumb rule: Ideally all spaces in a house should merge seamlessly

With the arrival of the British, the concept of passage and room entered India too. However, in tropical contexts like ours, we need not cut off air from a room, rather let the air move freely, either as gentle breeze in hot humid zones and displacement ventilation in hot dry zones.

Passages also retain the foul air, with no escape route. Besides tending to be darker, with no direct light from external windows, passages disturb perceiving the built area as a large entity. How narrow spaces hinder carrying furniture around need not be further highlighted. Despite all this, passages are taken for granted in most house plans even today, and felt as inevitable in public buildings such as hotels and hospitals.

Eliminating passages

By now we realise that we cannot avoid movement areas, and people need to move through even an entrance lounge. What could be eliminated are the exclusive narrow passages.

One option is make them wider, so a storage shelf or a mural art wall can be a part of the passages, turning them into multi-functional spaces.

Most areas can be designed such, one space merging into another like living room leading into dining space.

Classrooms in a school or bedrooms of a house may be accessed directly from a common space, without a connecting neck called passage.

How the space liberated from the bounds of passage contributes to enlarged internal area can be felt in all open planning buildings!

This is an everlasting attraction

While we seek light from the sky, we definitely will not welcome heat, mosquitoes or rain sprays. So, what is the best cover? 

Bring in nature: Create a classic skylight effect

The story of skylight can be a part story of architecture. It’s amazing to see how the idea continues to excite people even today and the reader’s mail response for the last few essays is a proof!

How did the idea of skylight originate in modern buildings? It is difficult to pin down a date or a specific architect as the starting point, but we can try a comical response.

In a crowded locality, when each house was tightly sandwiched with no light seeping in from either side, all that people perhaps could think of was look up and pray, “God, please give us light” As they looked up, the idea of opening to the sky must have originated!

Air vents

Anyway, while we seek light from the sky, we definitely do not seek heat, mosquitoes or rain spray. Accordingly, adequate care and proper design detailing need to be followed. Theoretically, what a skylight does is to let the air just beneath the glass get heated up, then let it escape through air vents placed there, so that fresh air rises from the bottom. Provision for air vents below the glass is mandatory, it ensures air movement through the building.

Vents could be simple voids in the wall, perforated blocks or even a few round pipe sections inserted into the wall. Without this detailing, the building ends up like a green house for growing vegetables, making living miserable.

Vents can be the easiest route for mosquitoes, hence fixing a mosquito mesh is as mandatory as having vents. These vents with the mesh should be at the highest location, with access to the mesh for periodic maintenance. Naturally, they should be towards the flat part of the terrace.

Also, adequate protection from possible rain sprays into the house should be provided in the form of a small chajja or deeply set vents.

Safety

Designing the skylights with the safety factor is another important consideration.

Let not the glass tops be a temptation for kids to play with, so guard them well with no sharp projections of glass from the wall edges.

Using flat terrace

Effective utilisation of the flat terrace despite having the skylights has always been a tricky issue. Of course, one may provide openings along a sloping or curved roof to avoid the discussion altogether; however, most often, they happen on the flat part.

After the staircase room, overhead water tank, may be some sloping roofs and such others, we are not left with much space in small plots.

Residents who need the terrace feel the pinch when the skylight cutout takes away some space too.

While there is no real solution to this problem, strategically positioning all these terrace needs by clubbing them in one area, to get the remaining area in one large parcel, could be a solution. If not, the terrace gets fragmented and would be of no larger use.

Caution

One word of caution: while skylights are an exciting mode of creating a better house, indiscriminate use of skylights can be the beginning of problems.