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The World Of Doors

By: Ashutosh Jha, Gensler, Bangalore

This takes me back to my childhood and my frequent visits to the grandparent’s village, the colourful doors were such a feature of each house.
The colourful wooden carved doors were the identity of that house. The doors are very technical! May be, before we get into the technical aspects of doors, it is important to understand the use and impact of doors.

Heavy wooden carved doors were such a striking feature of some of India’s old palaces. The carving, the detailing on the door reminds you of that era’s wealth, might and craftsmanship. Open chain latches were such a bold and striking feature of those days. That was a different time and different age, we moved much ahead. Beyond aesthetics, doors need to be utilitarian and coexist with the space.

The Colourful Wooden Carved Doors were the Identity of the Bygone Era

We rarely realize, but doors help us transitioning so swiftly between one to another space in the interiors. In the context of the house, do we ever realize going from dining room to bedroom, if the doors are open? They are an integral part of our life. Safety, security to aesthetics and well-being of occupants, they cover all aspects of our life. Let’s get deeper into this subject and examine where we are.

Understanding The Use Of Doors

The doors have their own world. It is utilitarian most of the times that goes hand in hand with aesthetics and these days a lot of debate is happening over its use to save energy, that’s where it becomes so important. The use of doors is very critical.

The major building types in India are office buildings, residential buildings hospitals, airports, hotels, educational institutes, individual houses, etc.
Understanding of doors is very critical. Let’s start with height and width.
Traditionally, most of the doors were 7’0” high with a width of 3’0” for single panel door or more depends on location. Still, most of the doors are 7’0” high, but we have noted some changes and we see doors up to 8’0” or 10’0” height in public as well as in residential buildings.

Modern Entrance Doors

Types Of Doors

What mentioned above is a general or generic basic understanding of doors. How do you select your doors? Let’s assume that you are selecting doors for an office building.

Your door type may be or most likely entrance door, which may be a revolving glazed door, you come inside and you might have a glazed door for a seamless flow between one space to another. The toilet will have a commercial board flush door and your sever room might have an access metal door. A glazed sliding door might lead you to an external balcony. And very importantly, you will have a fire door for fire exits. Just to name a few for better understanding.

Door Hardware

Every door requires hardware, just for basic understanding, commonly they will be hinges, door closer, handles, lockset to a minimum. In more detail, all the hardware will be specific to the use and material of doors, for example, we need a panic bar for fire doors and mop plate at the bottom of toilet doors. It’s extremely important to have the right set of hardware for each and every door.

Fire Doors

As an architect, our first priority is to make the building safe first in all aspects. It is good to see that fire life safety is not compromised these days and strict measures are fast becoming a norm. I see a lot of clients suggesting their buildings to be NFPA compliant. Perhaps, this is a sign that our construction industry is becoming more mature. Again, if I have to borrow a context, then I will borrow the office buildings. We need to have a fire staircase, based on occupant load and travel distance and we need fire doors for these stairs beside doors leading to an area of refuge.

All the stair fire door need to be based on exit width. If you are wondering, what is exit width, National Building Code of India suggests considering 10 square meters per occupant for office buildings, so we calculate the number of occupants per floor, again based on National Building Code of India’s suggestion, multiply that by 10mm and that much width of doors requires to be available for fire exit.

Let’s understand this in detail – typically a 5000 square meter floor plate will have 500 occupants per floor and will require 5.0 meter of exit width. So, if divided into three doors, two doors could be of 1.5 meters in width and one with a 2.0-meter width. We also noticed that these days, spaces are leased at 6.0 square meter per person, therefore the number of fire staircases and doors are very critical.

Typically, the fire rated doors will be hollow metal fire door and need to comply with IS 3614 part-1 & part-2 for stability and integrity, I will also suggest compliance with BS 476 part 22.

A door or shutter provided for the passage of persons, air or things, which together with its frame and fixture as installed in a building, is intended, when closed, to resist the passage of fire and/or gaseous products of combustion and is capable of meeting specified performance criteria to those ends.

A minimum 2-hour fire rating will be recommended and they should be tested at approved lab or CBRI (single or double leaf).

Door frame shall be ideally double rebate profile. Door leaf shall be 46mm thick fully flush double skin door with or without vision lite. The door leaf shall be manufactured from 1.2mm (18guage) minimum thick galvanised steel sheet. The internal construction of the door should be rigid reinforcement pads for receiving appropriate hardware. The infill material shall be resin bonded honeycomb core. All doors shall be factory prepped for receiving appropriate hardware and provided with the necessary reinforcement for hinges, locks, panic bar, and door closers.

The edges should be interlocked with a bending radius of 1.4mm. For a pair of doors, astragals have to be provided on the meeting stile for both active and inactive leaf. Vision lite wherever applicable should be provided as per manufacturers recommendation with a beading and screws from inside. The glass should be 6mm clear fire-rated glass of relevant rating. All doors and frames shall be finished with polyurethane aliphatic grade paint of approved colour.

The door leaf and frame shall have passed a minimum of 250 hours of salt spray test.

It’s very important that the entire door assembly (door and all hardware) be 2.0-hour fire rated.

Latest Trend In Door Selection

Glazed Fire Door: The latest trend even in fire life safety door goes for glazed fire rated door. They are available in 60, 90 and 120-minute fire rating. These doors match up with indoor/outdoor spaces and integrate seamlessly with the designer’s intent. Having a slim profile with integral astragal, they come in several thicknesses of glass (8, 10, 11, 12 and 14 mm) and type of fire glass are borosilicate and interlayered also available in frosted and toughened glass.

Glazed Revolving Doors

Self-Cleaning Glazed Door: The unique dual-action self-cleaning coating is located on the external glass pane and meant for external glazed doors. It has got photo-catalytic and hydrophilic properties, and works in two stages:

(Stage 1) The coating reacts with natural daylight to break down and loosen organic dirt.

(Stage 2) When it rains, instead of forming droplets, the water spreads evenly over the surface of the glass, forming a thin film and helping to wash away any dirt and reduce streaks. These are interesting, but I will prefer to see how they evolve more to become more popular among designers.

The High-Performance Glass | Glazed Door :

Glazed Sliding Doors

Similar to external façade glazing selection, a right balance of U-value, SHGC (Solar Heat GanCoefficient) and VLT (Visual Light Transmittance) is critical. The idea is to have the right amount of daylight or rather glare-free sunlight in your regularly occupied space. This is not only important for energy conservation, but daylight is also very important for the wellbeing of occupants as well.

I have elaborated (with the simulation) the impact of single pane vs double pane (or single glazed vs double glazed door) on a southern side of the building. It’s quite clear that double glass is more effective for daylight and energy with the above-mentioned performance parameters.

Conclusion:

The door has its own world and designing and implementing the right one requires a lot of effort. I was involved in a large transit oriented mixed-use development many years back and dealt with close to 1600 doors in one project, that led me to set up a dedicated team only looking at doors. I must say that future development for doors will be fascinating and I will keep an eye on them along with you.