For a bright bathroom
It has to be designed carefully, with proper ventilation too.
In the Indian context, ‘bright bathroom’ sounds like a contradiction! Majority of bathrooms in urban houses, with attached toilet, are ill-lit and badly ventilated.
Of course, we have quick fix solutions, without studying the root causes for the above experience. Fit a high wattage electric bulb and have an exhaust fan. Despite these two devices which consume electricity, many toilets and bathrooms are still dark during the daytime.
Actually the bathroom needs a large opening to brighten it up. There is a belief that larger the opening, lesser the privacy, which has no basis at all – a large window with translucent glass can ensure total privacy while a thin gap between the ventilator frame and the shutter can be a clear peephole. Ventilators in most buildings being rather low, most users keep them shut for the fear of privacy, incidentally blocking both air and light.
The generation before us knew the principle of ventilation that the warmer stale air moves upwards, being light in weight; hence the early toilets were provided with voids just below the roof level. During those days, with no steel and glass, these wall top openings were left with no shutters, which facilitated total movement of stale air.
The idea of continuous lintel band at 7 feet level coupled with the trouble of clearing cobwebs from this high opening made people stop the toilet ventilators at 7 feet height. With no escape, the stale air above this level comes to stay inside itself.
Most exhaust fans are operated when we are using the toilet with the doors shut, so no fresh air passes through the whole depth of the toilet. All that the exhaust fans throw out is the air immediately around them which often is fresh, so the stink continues.
Besides the general reasons, light is a prerequisite in a bathroom while fresh air is needed both for health and dry interiors. Bathrooms and toilets have been subjects of so many hilarious essays, that we may never realise how much they have in them for a serious ecological analysis too!