Usability is an important component of information systems acceptance. Independent consultants in the assessment of organisational intranets often perform heuristic appraisal, a common method of usability evaluation. However, there are alternative usability models that offer valuable analysis in the evaluation process. Using a government organisation's intranet as a case study, this paper assesses the value of an independent heuristic-based intranet audit by providing a comparable approach to assessment realisable internally in the organisation using questionnaires. Using a single case study, we empirically apply the Technology Acceptance Model (TAM), together with some heuristic aspects, to provide an alternative tool for intranet usability and acceptance. We provide insight into the usability impact of intranet design changes, and compare the findings of an external usability audit with the approach outlined An overall toolset for intranet evaluation is proposed as an initial step for further exploration and potential use.