ARCHITECTURAL SIZE AND ROOM DIMENTION CRITERIA ...

DESIGN IDEAS BY AR. VIKASH ANAND

# Classical design proportions revolve around the concept of "the golden mean". The mathematical ratio between the larger side and shorter of a rectangle is 1:1.618. This has been recognized by the Greeks, Egyptians and Renaissance artists and designers.

# At this point you now know where the rooms are all going to go, now it is time to size and shape each of the rooms.  Note that here, size is the minimum size to accommodate the activity.  Because the rooms have to fit together in one package and is constrained by structural considerations, there is a lot of give and take as to what the actual size of a room will be.  This stage often involves much compromise, and a lot of drawing trying to get everything to fit and work together, and is an area where an experienced architect or designer is much better at this than anyone else.


1) The Size of Rooms
The critical size of a room isn’t its exact dimensions, but its perceived size, which is related to our own size. There is a day lighting constraint on rooms in that light will only penetrate 12-15 feet, so rooms should never been deeper from a window than that. The feel of a room varies from cramped to cozy to comfortable to spacious and on to voluminous.  Breaking up the surface treatment of a floor or walls into segments tends to make a room seem smaller, while views from a room across to other rooms, or views open up to the outside tend to make them look bigger. Raising the ceiling height can make a room look bigger, but only if the dimensions of the room are greater than the ceiling height, in which case the room will look smaller.
There are multiple systems for sizing rooms proportionally, both in terms of the ratio of length to width and of floor area to ceiling height.  A couple of these ideas are the golden section, which is a ratio of 5 to 8, and in terms of bamboo mats (which are themselves human scale).  For many people, its good enough to just avoid making one dimension particularly larger than another.
A room's minimum size can be determined by laying out furniture in it and then allocating space for passage around it. This is a good place to start and then let rooms expand as they joint together.  In this process all rooms will tend to get big, and significant work must be done to keep the building from growing too much.


2) Ceiling Height
The height of the ceiling affects the feeling of intimacy: a very tall ceiling will make people feel like they're further apart, while a low ceiling will make them feel like they are closer together.  Public building usually have ceilings that are ten feet or so tall because the people in them are strangers. The eight foot ceiling was adopted for residences because its a good compromise.  The common areas could benefit from a slightly higher ceiling (maybe 8'6" or 9, but probably not more than 10) while bedrooms, bathrooms and home offices could easily have a slightly lower ceiling (by probably not less than 7'6").  When a taller ceiling is used in the common areas, many people will keep the kitchen ceiling lower.
Vaulted ceilings under a roof can be nice, but you need to keep in mind that warm air will rise, so if the ceiling gets too tall, the warm air will all go up there.  There is few practical reason for a ceiling much more than ten feet, except around stairways, when there is a good reason to vault the ceiling, or to specifically capture hot air¹. Ceilings two stories tall not only cause a problem with heat, but they're a colossal waste of space.  Cathedral ceilings are best left for churches, where they belong.


3) Placement and Amount of Windows
Windows serve a multitude of purposes- they provide daylight, they provide passive solar heat, the provide ventilation and they provide a connection between inside and outside.  On the down side, they are poor insulators and do not provide any privacy.   Compared to insulated walls, even the best windows available lose anywhere from three to ten times as much heat through them, depending on how you do the comparison, and so windows need to be used very wisely.   The shape of the house must be designed with windows in mind so that each room can have sufficient daylight,  and so that passive solar heat is taken advantage of without incurring excessive heat loss.
Every house is a passive solar house to some degree, only if its not designed that way the result is some combination of not capturing the available winter heat, and capturing too much of the summer heat.  While fully passive solar heating is a challenge, getting a size able chunk (25-50%) of your winter heat is quite easy (assuming it is available at the site).  Details on this are in the solar section.
Most people find daylight preferable to any kind of electric light, and like solar heat gain, it’s a free resource that should be taken advantage of it whenever it is available.  Even on a cloudy winter day, there is significantly more light outside than there is in a room lit with electric light, and on a sunny day there is many times more light yet.  Our eyes are amazingly adaptable to a wide range of lighting conditions, but for tasks like reading, they operate best in the mid ranges.  Where an overhead electric light is often too dim, direct sun, or even a bright cloudy day is too bright for reading.
Issues of day lighting are normally only dealt with superficially in residential construction, and unlike other aspects of design, there are no available formulas to calculate window size based on daylight requirements.  As a result, the only alternative is to rely on experience or build a model and measure how it performs.  Either way, the amount of window area in a room should be sized to provide a reasonable amount of light. The general rule is that never build any space that is more than 12-15 feet from a window, since that's as far as light penetrates, and always try to put windows in a room so that there is a window facing in two or more directions, so as to prevent dark shadows and create a more even, diffuse light.  Of particular concern to anyone trying to maximize passive solar gain is the problem of excessive amounts of light due to large glazing areas.
Windows create a connection from inside to outside, and the degree of that connection is determined by both the size of the window and the height off the floor of the windowsill. A sill height of 4’6” will create nearly total privacy, but very little connection with outside, while a sill height of 12” will make the outside feel part of the room, but provide no privacy.   Bringing the window sill all the way down to the floor does create a greater a connection with outside, but also decreases the sense of being protected.
Views are wonderful, but by making a view broadly visible from many places in the house by using lots of glass reduces its specialness.  Instead pick an area or two, make the view a centerpiece of those areas, and let all the other windows be the size they need to be, ignoring the view.
As with day-lighting, public spaces tend to want a greater connection to the outdoors, while private spaces want a lesser one.  People like to be able to watch the weather, see who is walking by, and enjoy the landscaping, and so having some windows with a low enough sill allows this.  Keep in mind that a very low sill can make you feel exposed, so there is a tradeoff there in determining sill height.  When the outdoor landscaping creates a natural privacy barrier, the windows in private spaces can be opened up to it, creating delightful spaces, but few urban lots allow for this luxury.