English to Spanish Bus/Financial Finance (general) Finanzas

Hola a todos,

Este es el fragmento:

In total 9 transactions over £100 per sq ft have
been achieved in the first six months of
2013, all of which occured in Grade A
units of under 10,000 sq ft in the West
End's core.

¿Cómo se traduce Grade A unit? En el texto también aparece "Grade A rents"

Gracias.