To read Part I of this article, click here.

Plan of attack The average person can’t exactly afford to build a house with walls four feet thick, or a roof that’s 20 feet high. The best you can do is to insulate the heat-absorbing sides, and hope that load shedding ends (yeah, right!). The South-West side and the roof is where most of the heat is absorbed from, so build your living and sleeping area on the North side, and try and put spaces like stairwells and bathrooms on the South or South-West side, so they act like a double-layer to keep away the sun. Yes, I realise that this might not be the ideal way to show the world the massive white pillars holding up your triangular porch roof, but it will be cooler.

There’s a decent market for insulation materials for the roof; unfortunately, people haven’t started insulating their walls yet – even though they’re willing to install toilet flushes that cost a lakh. A good way to judge your material is to look up its “R-value” – the unit of thermal resistance. The higher the value, the better heat protection you’d get. Most contractors use thermophore (polystyrene) sheets, better known as ‘packing sheets’. They’re cheap, easily compress under weight, and are completely useless as insulating material!

The insulation sheets manufactured by Diamond and Moltyfoam, among others, are your cheapest useful bet. They also offer a spray service, where they spray polyurethane material on the roof. It currently has the highest R-value in Pakistan. Obviously, the thicker the layer, the better the insulation. Practically speaking, the depth of your insulation will depend on the depth of your pockets, do your homework and read what Wikipedia says about it. I went for a 1.5-inch polyurethane spray.

Once the roof is poured, they put a layer of sealant and plastic sheets with a layer of mitti on top. Finally the tiles are laid to close off the structure. I asked the masons and the contractor the reason for the mitti; they said they didn’t know, they’d always done it that way. I asked the architect, and after much deliberation, learnt that the mitti acts as a filler to level out the floor for the tiles to lie on. Some might think that its insulation, but the thin, compacted layer that goes on top is hardly enough to do anything else. I suggested that we mix toree (cut straw) to increase the insulating property of the material, only to face a great deal of resistance. “Why do it?” “It’s pointless!” “Nobody does it.” “We don’t have vendors who supply straw!” Those were the arguments that I had to fight against. Even at the time of the ‘pouring’, the workers thought it was funny; “You’re a strange man,” they’d say. “Why bother with this?” I couldn’t even convince them to use 3/4 straw in the mix. They thought the entire house would collapse or something equally dramatic would happen. In the end I just gave up and said I’d live with half-and-half. So on top of the insulation spray, we added the mitti-straw mix, and then tiles on top.

The icing on the cake When it came to the roof, I had it painted white (after being the butt of jokes all week from the painters), which is an excellent way to reflect sunlight. That was the roof taken care of. The South-West side of my house had a stairwell and a bathroom, shielding my bedroom from the hot side. I had also planned a place for a neem tree to be grown between the hot setting sun and my house – a fully matured neem tree can provide shade to an area of up to 500 square feet.

Intelligence inside Personally, I think the best material in Pakistan for floors is marble. It’s cool, looks great, and it’s cheap. Well, cheaper than Spanish tiles that lately seems to sell more than roghni naan. Fake wood floors are also very popular nowadays, but I shudder to think what a wet mop every day for a couple of years would do to that. Plus, when you come home in the evening after a hot day outside, you want to take your shoes off and feel a cool floor underneath your feet. You don't want to feel like you’re walking on a warm creaking coffin that’s not even real wood! But fake wood aside, I didn’t even have enough money for marble, I wanted to save as much money as I could on the floors and spend it on really good double-glazed windows. The cheapest floors I could find were plain concrete – the kind they do in huge factories or retail stores like Metro. That cost me 10 rupees less per square foot than the cheapest marble. Now it’s costing me my sanity because my wife can’t stop complaining about the ugly floors (“they aren’t shiny!”). She is, however, very happy with the windows that we have.

So after getting cheap floors and leaving the ceiling “unplastered”, I saved more money by buying locally-made electrical switches. The European ones were too expensive, the Chinese supply too erratic (a year down the line you won't find a replacement that looks the same), whereas the Pakistani company offered a five-year warranty. I did the same with bathroom fixtures. Although the sinks and WCs aren't all that pretty, the price difference of almost 20 grand per piece kept me satisfied.

After saving all that money, I went all out on the windows. I ordered argon gas-filled double-glazed windows; which I consider to be the Rolls-Royce of windows in Pakistan. However, the frames of these windows weren't well sealed, which resulted in me sealing all the window joints with a silicon gun. The idea was to make the rooms completely air-tight, so that if I have the air conditioner on there's no leakage and loss of efficiency. For that I had to convince the carpenter to not do what he'd being doing for generations.

Sealed for comfort I asked him to install a four-sided chokhat (frame) for a door, instead of the usual three-sided one. I also wanted it to be seated on the floor, so I could add rubber all around the door – much like a car door. What followed were the usual questions and arguments from almost everyone. “You'll keep stubbing your foot on the chokhat, nobody does that” and so forth. I tried explaining that cool air settles down, and flows out from the bottom of the doors when you have air conditioning in the room. They laughed. In the end I had to tell the carpenter that it was my money, so feel free to rip me off but do as I say. Finally, he made a four-sided frame, left a slit in the middle for the rubber so the door would sit flush against it, effectively sealing it. I found a suitable rubber strip from the car spare parts market, and after much cajoling and ego-stroking the carpenter, got him to add it in.

Now, with the windows shut, closing the room door made a 'whoop' sound, much like a car door closing - my AC was going to have it easy.

One major thing was yet to be done; I had to figure out a way to get the hot air out of the rooms and bring cool air in, without depending on electricity. This dilemma brought me to consider Earth tubes. These are tubes buried in the ground deep enough to take advantage of the more even, year-round temperature at depth. Air from outside a house is run through the earth tubes to heat or cool it before it is introduced into the house. In summer, the earth is cooler than the outside air temperature and air will be cooled as it goes through the tubes, and the opposite in winter. I decided to modify the design and instead of running it underground, I built an air-inlet at the bottom of the wall, opening out to a shaded flower-bed with a water feature nearby to keep the ambient temperature down. That's the cool air coming in taken care of, now I had to get the hot air out.

Since hot air rises up, I had a vent built on the top of the wall on one end of the room that went all the way up to the roof, like a chimney. Essentially, it replaces the hot air by the cooler air coming in from your cool air inlet at the bottom of the room, and that alone adds an air-current in your room that's at least three/four degrees cooler than the static air in the room. I also had a double-layered water tank on the roof coloured white so that I don't get boiling hot water in the summer. To avoid total reliance on electricity to drive a pressure pump, I installed one-inch pipes all the way from the over-head water tank to the bathrooms to increase water pressure.

After all that, I coloured the entire house pure white from the outside, planted broad-leaved deciduous (sheds leaves in the winter to let the sunlight through) trees on my sun path, installed one LED bulb (they're cheaper now, but were more expensive a couple of years ago) for each room that ran on the UPS.

Now, after all the labour I bore, my eco-friendly house as compared to a conventionally-built house offers: 1.    Comfortable temperature all the way till mid-May. 2.    Air conditioner takes about 15 minutes to cool the room to 26?C in my 12x14 bedroom. 3.    The room retains a comfortable temperature of around 26?C up to five hours after the AC is switched off, perfect with a fan. 4.    The electricity bill on average for the summer months is 6,500 rupees, compared to up to 20,000 rupees for a similar usage and covered area of a conventional house. 5.    The highest temperature I've ever recorded in my upper floor has been 31?C. The average temperature of an upper floor room of a regular house in Lahore in June is 36?C.

What you can do? After all that is said and done, if there's one thing you should do, and that you can do right now in your existing house, is colour your rooftop white. It costs as little as 2,000 rupees for a whitewash and will take off at least a couple of degrees. Other than that, buy yourself an infra-red temperature gun; it’ll make you look cool and you can actually see how hot the walls/roof/elbows are on any given level in your house. Buy a minimum-maximum temperature gauge and put it in your room. Notice how long it takes for the AC to cool the room down to 26?C from normal on an average summer day. Find a Sun Path Calculator on the internet, enter coordinates of your house from Google Earth into it, and see where the sun is going from April to August. See if you can plant a tree or cover that particular wall with a vine or creeper.

I think, with the prevailing electricity crisis in the country, pretty soon the only electricity we get will only be sufficient to charge our mobile phone batteries and laptops – all the more reason for you to build a smart house.

Note: The design of the house was done by Dr Gulzar Haider and his team