As you asked for this both in Swedish and English, I am just putting in a note to distinguish the two (as both of the above are correct).

As you asked this in regards to architecture, I would note that 10,000 square meters is the equivalent of 1 hectare (if using the metric system as one would in Sweden and in my native country Canada).

Note, however, often farmland is referred to as acres, in which case a hectare is 2.741 acres (US and in Canada's countryside).


ENGLISH DEFINITION:
hectare

\Hec"tare`\, n. [F., fr. Gr. ? hundred + F. are an are.] A measure of area, or superficies, containing a hundred ares, or 10,000 square meters, and equivalent to 2.471 acres.


Source: Webster's Revised Unabridged Dictionary, © 1996, 1998 MICRA, Inc.


hectare

n : (abbreviated `ha') a unit of surface area equal to 100 ares (or 10,000 square meters)



SWEDISH DEFINITION

hektar [hekt'a:r] hektaret hektar hektaren noun
ett ytmått (=10 000 kvadratmeter)
a measurement - 10,000 square meters.