Purpose - The conservation management plan (CMP) for a heritage building establishes the nature of the work required to conserve, maintain and enhance the cultural heritage significance of the property. A missing element from many CMPs has been a realistic consideration of the cost of the work at this early stage. The paper aims to show how cost planning of works in a heritage building's conservation environment can be achieved. Design/methodology/approach - A background to the structure and preparation of CMPs from the literature in Australia and the UK is presented. Experience gained from the costing and budgeting in the CMP for several heritage projects in Australia and the process, are both described, summarised and discussed. Findings - The CMP provides a comprehensive working management guide for owners and other stakeholders to follow when carrying out works to the heritage property and includes components such as current condition, legal responsibilities and statutory obligations, sequencing and timing of proposed actions. The addition of significant financial information such as maintenance programmes, funding sources, long and short term costs, financial resources of owner, technical constraints, current owners needs and requirements and conflict resolution provides the possibility of making the CMP a more valuable document to the funding agencies and the building's users. Practical implications - Heritage clients and users increasingly need to know their likely financial commitment before work commences. This early stage cost advice (indicative costs) integrated into CMPs can establish realistic budgets for decision making. Originality/value - The addition of the cost of the works as proposed in a CMP can support client and community groups in making requests for funding from the various government and private agencies with an interest in, or responsibility for, the future care and use of these properties.