8SThe crofter shall not, without the consent in writing of the landlord, erect or suffer to be erected on the croft any dwelling-house otherwise than in substitution for a dwelling-house which at the commencement of this Act was already on the croft:
Provided that, if at the commencement of this Act there was no dwelling-house on the croft, the crofter may erect one dwelling-house thereon.