There are various types of conservation reports that typically get commissioned for heritage buildings:
Architectural Heritage Impact Assessments (AHIA)
This type of report typically accompanies a planning application to a Protected Structure. The report assesses the impact of the proposed development on the building and may recommend mitigation measures and include appropriate conservation method statements for the works. The report would include a historical account of the phases of development of the building, an assessment of significance, and a description and photographic inventory upon which the impact assessment is based. Appendix B of the Architectural Heritage Protection Guidelines (2011) gives guidance on the format and content of an AHIA report.
Visual Impact Assessment (VIA) Reports
This type of report assesses the visual impact of a proposed development on an asset (ie: a building or site). The development may be works (for example an extension) to the building itself or it be related to works on a separate site remote from the asset. In the latter case, the report assesses the visual impacts of the development on the asset from the relevant views that are affected. Photomontages are typically central to the VIA report. A key reference for the preparation of VIA reports is the publication Guidelines for Landscape and Visual Impact Assessments (Landscape Institute).
Conservation Management Plans
Conservation Management Plans assess the condition and significance of a historic building or place and help to develop a long-term management strategy for the asset. The plan would include the research element of the AHIA report to establish the significance of the asset as well as a detailed condition report of the structure and a schedule of necessary maintenance and conservation works graded by a timeframe and level of urgency.