The efficiency of the plan is measured as-

1. For utility buildings - Minimum circulation area. Lower the percentage of circulation area higher is the efficiency. It can be expressed in ratio of Total Carpet area: circulation area like corridors, passages etc. (Balconies, verandas and lounge etc etc if meant for particular use should be included in Usable areas, or other wise in circulation area. A space though meant for an activity but if surrounded by other spaces having movement through the space, it ceases to be activity area and so practically becomes circulation area, and so should be included in circulation area. All spaces should be defined in any one category and then the ratio should be found to determine the efficiency.

2. For building having movement as main function (Viz. Shopping Centers, Museums, Art galleries etc.) The rational percentage should be achieved. The area should not named as circulation or link areas but as MOVEMENT AREA. It is usable area. The efficiency of such plans is to be measured by provision of the movement area per person at peak hours. For its optimization the movement area per person at peak hours (How many hours ? Can peak hours be staggered? ------??) and movement area per person at approximately Zero hrs. should be compared. A proportionate average (Depending upon duration of Peak and Zero Hours) should be taken up for optimization.. In general 4 Sq. Meter per person at peak hours can be taken up as efficiency factor and so should be corrected against zero hours @ 1 Sq. m. per person. So as optimum efficiency value for Building with Movement as main function can be taken up as (assuming Peak Hours as 4 hrs per day) 2.5 to 3.0 sq. m. per person. Of course this cannot be generalized and should be decided logically specific to situation and location.

3. For institutional buildings : Availability of optimum usable space and linkage based on the interlink between them decides the efficiency. Draw the interrelation diagram. Lesser the crossing between the lines of interrelation more is the efficiency. In physical plan measure the total length of the lines interlinking various activity spaces. Lesser the total length more is the efficiency.

In General efficiency of plan can also be measured by ratio between available carpet area in functionally usable spaces and total plinth area (Or floor area on each floor). Higher the ratio more is the efficiency.

I hope this is enough though some more considerations can be put forth.

What exactly your mean ?

Interesting topic, any ideas?

Circulation.

yes can you be more specific. I am thinking about Integration of systems, 3D representation to eliminate clashes.

I agree with inocencia, its all about circulation factor.

Orientation related to environment, Accessibility (Circulation), functional relations of spaces, and finally ,Relation with Surroundings.

Yes, but it seems a broad answer for me, if that so everything related to building funtionality.

Please provide a framework for 'influential factors' and define 'functional'.

Thanks.

I mean how you say that this layout plan is better than another functionally..in terms of flexibility, circulation, accessibility, functional zones or sectors......etc.

First you need to have the parameters you want to achieve, e.g. in housing you want service areas to be close to social areas or you want bedrooms to be near each other. Then you use measuring technics, e.g., space syntax, to compare between different layouts - than you may say that a plan is better than another functionally according to the apriori requirements you established.

The measurable factors that influences funcionality may be (depending on the type of building): capacity, spaciouness, acessibility (connectiivity), communicability. But it can also be acoustic confort, visual confort, .... Depends on what you mean by "functional".

I think, first of all.... It depends on our ability for client basic need assessment.

In one (hyphenated word) - multi-functionality.

We want to minimize circulation space not because it's unimportant but because narrow circulation spaces like corridors can't be used for anything else except...circulation. A living room will need some space for us to walk around, but we don't mind it because that space is part of what we conceive to a living room.

In my work with housing layout, I try to transform the roads in front of the houses - that mainly serves cars - into courtyards that can also serve as an outdoor play area for children, a pocket for planting big trees, and to serve as a communal space.

Architect Gary Chang from Hongkong transformed a small 300sf apartment into some 24 configurations to create spaces for living, dining sleeping, cooking, bathing, home theatre, etc with the help of sliding walls: http://planetgreen.discovery.com/videos/worlds-greenest-homes-hong-kong-space-saver.html

You can also see my point by looking at the many products - folding walls, sliding seats etc that extend the ways multi purpose halls can be used.

So miniomize mono-functional spaces, maximize multi-functionality

The efficiency of the plan is measured as-

1. For utility buildings - Minimum circulation area. Lower the percentage of circulation area higher is the efficiency. It can be expressed in ratio of Total Carpet area: circulation area like corridors, passages etc. (Balconies, verandas and lounge etc etc if meant for particular use should be included in Usable areas, or other wise in circulation area. A space though meant for an activity but if surrounded by other spaces having movement through the space, it ceases to be activity area and so practically becomes circulation area, and so should be included in circulation area. All spaces should be defined in any one category and then the ratio should be found to determine the efficiency.

2. For building having movement as main function (Viz. Shopping Centers, Museums, Art galleries etc.) The rational percentage should be achieved. The area should not named as circulation or link areas but as MOVEMENT AREA. It is usable area. The efficiency of such plans is to be measured by provision of the movement area per person at peak hours. For its optimization the movement area per person at peak hours (How many hours ? Can peak hours be staggered? ------??) and movement area per person at approximately Zero hrs. should be compared. A proportionate average (Depending upon duration of Peak and Zero Hours) should be taken up for optimization.. In general 4 Sq. Meter per person at peak hours can be taken up as efficiency factor and so should be corrected against zero hours @ 1 Sq. m. per person. So as optimum efficiency value for Building with Movement as main function can be taken up as (assuming Peak Hours as 4 hrs per day) 2.5 to 3.0 sq. m. per person. Of course this cannot be generalized and should be decided logically specific to situation and location.

3. For institutional buildings : Availability of optimum usable space and linkage based on the interlink between them decides the efficiency. Draw the interrelation diagram. Lesser the crossing between the lines of interrelation more is the efficiency. In physical plan measure the total length of the lines interlinking various activity spaces. Lesser the total length more is the efficiency.

In General efficiency of plan can also be measured by ratio between available carpet area in functionally usable spaces and total plinth area (Or floor area on each floor). Higher the ratio more is the efficiency.

I hope this is enough though some more considerations can be put forth.

Thanks and high appreciation for all, Hambarde, Ghazali, Sara, Maha, and others...all these discussions are so interesting...my topic is about all of these...specifically, functional sectors of interior spaces (interactions and relations), flexibility of interior spaces, the points of entrance and accessibility to inside the building, social privacy, connectivity of buffers and zones (social dimension in configuring interior spaces..... )..

Upgrading the performance and the efficiency of the interior spaces within buildings;Proper handling

of the functional dimension of spaces (internal and external) for buildings and surrounding areas plays an influential role in continuity and sustainability of these spaces in its functions efficiently over time. Integration and depth minimizing and maximizing of spaces, zones-sectors, activities and services...etc

It can be said that a building achieves its function not through its built form but mainly within its plan-layout spaces. Accordingly, buildings create and order the empty spaces in which their purpose and function take place. Social meanings in buildings take place within the spaces of the buildings, and the ordering of spaces in buildings is really about the ordering of relations between people...

The functional relationships reflect the characteristics of spatial configuration of the building based on the feature (property) of segregation as an indicator to measure the degree of functional – social efficiency of space, because the structure of spatial relations of any building depends on the way of handling the determinants of space (walls and floors) which include joints of the kinetic links, on the one hand.

On the other hand, the magnitude of kinetic penetrations in these parameters reflects the permeability of space within the spatial system (plan layout), which in turn reflects the flexibility and integration of interior spaces.

Last but not least, functionality of the building is approached in architectural design mainly as a sequence of human actions coupled to equipments in order to satisfy specific practical requirements on a daily basis inside a given spatial system (plan layout)....Functional factors such as the relationships between spaces and activities, appropriate axes of movement, flexibility, suitability, safety…etc. are the key aspects of the

building layout design. These factors are closely linked to occupant activities and directly to his organizational performance. The functional considerations play an effective role in the success of the building entirely. Accordingly, the incorrect configurational decisions give inefficient and unaccepted functions......

Dear Mustafa, In spite of all above you must remember the efficiency is not the quantity but quality. It can be tested only when used, though we must try maximum while planning/

But, can quality be quantified? If no, how can we measure efficiency? If we can only test quality after construction a lot of problems may occur that could be avoided...

In space syntax theory and methods, all above keywords related to the functionality can be measured by special formula and equations....

Dear Sara Eloy, Yes quality can be quantified. Even Music is quantified mathematically. But still as melody (Qualitative aspect of music) is something more and beyond Harmony (A mathematically quantified attribute of music) similarly even if one may determine and workout efficiency with formula, equations, ratio and percentage, yet EFFICIENCY I N REALITY IS BEYOND. Efficiency includes certain behavioral and psychological considerations too. For example a fruit may be nutritious and so efficient but if one who has no liking for that will not be benefited. I am not raising unnecessary controversies and am not against precise and objective decisions. efficiency must be determined mathematically and objectively. YET IT MUST BE REMEBERED THAT THERE IS SOMETHING BEYOND MATHEMATICS. THAT, TOO, MUST BE KEPT IN MIND.

Thinking about functional efficiency as an environmental characteristic which allows users to do what they want within a building in a fastest and safest way. Many researches in the Ergonomics and Human factors have their focus in this issues and most recent studies point Virtual Reality as an interaction environment to study and predict patterns of flow and pleasure of users, using objective and subjective methods, while they travel through simulated complex buildings. So, it is possible to test design decisions with potential users before applying this decision in the final project.

Dear Elisangela, I totally agree with the aspect as measure for efficiency. Actually in last comment I was mainly concentrating upon the efficiency from point of view of Space utilization.

As you have mentioned functional efficiency as an Environmental characteristics is a very valid consideration.

Additionally, "Energy efficiency" also can be a valid measure in determining the efficiency of certain buildings.

I agree with Sara. Cost factor definitely is one more scale to measure the efficiency of the design. So also there are other aspects. One should list them all and determine the different scales for different aspects. The scales can be quantified in no. values and can be totaled to determine final efficiency value. the weight for different aspects will depend upon the type of project and priority consideration for each of them This can not be same for all types of buildings.