1. In administrative law, judicial review is fundamentally different from an appeal: on review, courts determine lawfulness, not correctness or merit. Courts must not substitute their own decision for that of administrative bodies but only determine whether the decision should stand. 2. Courts must give due deference and respect to decisions of administrative agencies with special expertise and experience, particularly where decisions require balancing competing interests and policy considerations. The extent of deference depends on the character of the decision and identity of the decision-maker. 3. For a decision to be reviewable under PAJA section 6(2), it must be shown that the decision-maker was materially influenced by an error of law, acted irrationally, or was so unreasonable that no reasonable person could have made that decision. 4. Section 99 of municipal planning by-laws requires a staged, balanced approach: threshold compliance with spatial development frameworks and desirability, followed by consideration of all relevant factors including heritage, socio-economic impact, traffic, compatibility with surroundings, and whether conditions can mitigate adverse impacts. 5. Heritage concerns in Heritage Protection Overlay Zones, while important and requiring genuine consideration, are not pre-eminent or the sole criterion but must be balanced against the full basket of section 99 factors. 6. Where an initial decision-making process may have flaws, a de novo appeal that constitutes a re-hearing of the merits can cure those defects if the appellate decision-maker properly considers all relevant factors and is untainted by reviewable irregularity. 7. The mere labeling of litigation as "constitutional" is insufficient for Biowatch costs principles to apply; the case must raise genuine, substantive constitutional considerations and not simply invoke constitutional provisions as background to statutory interpretation disputes.