In my opinion, since the case is pending before the court on a different issue and there is no stay order against you or restricting your business and its related activities (including the one what you have proposed to go ahead now), there is no problem to complete the proposed modification/renovation/interior decoration. As it is, based on the judgment, either the of the party are planing to prefer an appeal against the judgment before the higher court, so there is breathing time to recover the amount spent on such investment through improvised business . Go ahead if you think that you will be able to tackle the external pressures from the landlord and are confident about other issues in your favor.