Faute de contexte, je suppose qu'on parle d'un secteur, une agglomération ... et non de l'intérieur d'un édifice ...

As the name suggests, carpet area means the area of the property where you can lay your carpet, measured wall to wall (Checkout the illustration below). This is the actual area which you can call your personal space and you should be really concerned about.
Areas included in Carpet Area
• All Rooms – Living Room, Bedrooms, Dining Room, Dressing Room, Other Rooms.
• Kitchen and Bathrooms
• Stores and Balconies
Areas not included in Carpet Area
• External and Internal walls
• Common Areas

Built Up Area or Plinth Area is the total covered area of the apartment or commercial property unit. It can be calculated by adding areas of utility ducts within property unit, internal and external walls to the carpet area (Checkout the illustration below). As a rule of thumb, built up area can be calculated by adding 10% loading factor on carpet area. This term is not so important while buying a property as almost all developers sell the property on super built up area. However, this term becomes important while dealing with government departments for eg. In many states, property taxes are levied on built up area/ plinth area.
Areas included in Built Up Area/ Plinth Area
• Entire carpet area
• Internal and External Walls
• Utility Ducts within walls of the unit
Areas not included in Built Up Area/ Plinth Area
• Common Areas

Super Built Up Area means built up area plus common areas proportioned to a unit (Checkout the illustration below). As a rule of thumb, the super built up area can be calculated by adding a loading factor to the carpet area, which may vary from 15% to 50%. The lower the factor the better it is for you as a customer as you get a higher carpet area for the same amount. The biggest catch is the calculation of common areas, where you should pay most attention to.
Areas included in Super Built Up Area
• Entire Built Up Area
• Common Areas – lobby, lift ducts, staircases, pipe ducts/ shafts, air ducts, covered community centres/ clubs, other covered common facilities.
Sometimes, Super Built Up Area is also called as usable area, saleable area or just super area.
http://assetyogi.com/carpet-area-plinth-area-super-built-up-...
(taken from Nicolas’ link)

Domain AGRICULTURE, FORESTRY AND FISHERIES
en
Term usable area
fr
Term surface utilisable
http://iate.europa.eu/SearchByQuery.do?method=searchDetail&l...

La surface utilisable dans le bâtiment de l'Arc est adaptée pour environ 550 employés, selon les pratiques standard des Nations Unies.
icc-cpi.int
The surface area of the allocated ARC building is suitable for about 550 employees, according to standard United Nations practices.
icc-cpi.int

A chaque étage, un couloir périphérique qui mesure 90 [...] centimètres de largeur a été aménagé près des murs extérieurs, ce qui a entraîné une perte importante de surface utilisable.
oag-bvg.gc.ca
Typically, a 90-cm-wide walking space is being maintained at external walls, which has resulted in a considerable loss of usable area.
oag-bvg.gc.ca

Avec ces rénovations, l'installation bénéficiera d'un meilleur rendement énergétique, d'une [...] réduction des coûts d'exploitation, d'une plus grande surface utilisable et d'une sureté et d'une intégrité structurale améliorées.
wd-deo.gc.ca
These renovations will improve energy efficiency, lower operating costs, increase usable space and enhance safety and structural integrity
wd-deo.gc.ca

Les facteurs tels que la disponibilité d'une source de chaleur, la surface utilisable, le type de construction, le volume et l'isolation du bâtiment, le type et la température de répartition de la chaleur dans la [...]
ochsner.fr
Factors such as availability of a heat source, useable ground area, construction type, size and insulation of the building, type and temperature of heat distribution in the house, etc. all influence the decision.
ochsner.com

Le débit de ventilation indiqué doit être maintenu pendant les périodes d'occupation du locataire et, pour le calcul des exigences relatives à la [...] ventilation, l'occupation maximale estimée (basée sur la surface utilisable) ne doit pas être inférieure à celle prescrite par [...] la norme ASHRAE pour des locaux à bureaux standard et à celle définie ici pour les installations de nature particulière.
tpsgc-pwgsc.gc.ca
The defined ventilation rate shall be maintained during the occupancy period of the Lessee and to calculate ventilation [...] requirements, the estimated maximum occupancy (based on the net usable area) shall not be less than as specified in the ASHRAE [...] standard for standard office space and as defined herein for the special systems.
tpsgc-pwgsc.gc.ca
http://www.linguee.fr/francais-anglais/traduction/surface ut...

Meanings of "usable area" in French English Dictionary : 3 result(s)
1 General usable area aire utilisable [f]
2 Real Estate usable area surface utilisable [f]
3 Sports and Organizations usable area superficie utilisable [f]
http://tureng.com/en/french-english/usable area

Subject field(s)
• Plans and Specifications (Construction)
• Real Estate
usable floor area CORRECT
usable space CORRECT
usable area CORRECT
DEF
That area within the outside walls measured and computed in the same manner as "Rentable Area" but excluding common use areas which serve the entire floor or building, known as Accessory Areas.
DEF
The net floor area in a building after deducting the area occupied by lobbies, corridors, rest rooms, cafeterias, etc.

Domaine(s)
• Devis, cahiers des charges et plans (Construction)
• Immobilier
superficie utilisable CORRECT, FEM
aire utilisable CORRECT, FEM
surface utilisable CORRECT, FEM
CONT
Celle-ci comprend les colonnes et les surplombs que nécessite l'ossature de l'immeuble, mais non les [...] secteurs auxiliaires [...] ni les aires de service. La superficie utilisable [...] est calculée en mesurant à partir de la paroi intérieure du mur extérieur [...] jusqu'à la paroi intérieure opposée du mur extérieur [...
http://www.btb.termiumplus.gc.ca/tpv2alpha/alpha-eng.html?la...

Surface habitable 205 m²
Surface utilisable 305 m²
http://www.homegate.ch/acheter/maison/lieu-troistorrents/lis...

Au coeur du triangle d'or du Luberon, à vendre, mas en pierres d’environ 700 m² de surface utilisable situé sur un terrain de plus de 5 hectares.
http://www.rosier.pro/details-au coeur du triangle d or du l...

Villa T4 mitoyenne 2 niveaux Sanary Plaine du Roy surface utilisable 82m2 (70m2 Carrez) avec jardin clos 130m2 et bassin, Sud
Surface habitable 70m² Carrez (82m² utilisables)
Surface terrain 130m²
http://www.agence-interimmo.com/details-villa t4 mitoyenne 2...