Purpose
This research presents the development of a Building Passport for Sustainable Conservation (BPSC) as a questionnaire with a set of 23 core indicators, for a baseline assessment of heritage buildings. The aim of this tool is to identify priorities for future interventions, by recognising the contributions of heritage buildings to sustainability that should be preserved and the fragilities that need to be improved.

Design/methodology/approach
The BPSC uses a selection of core indicators for sustainability observable on heritage buildings. It was applied to four different case studies of modern heritage in the Netherlands, to verify its applicability and limitations.

Findings
The results suggest that this tool has the potential to contribute to an expedite assessment, reaching consensual evaluations of priorities for sustainable conservation, while reducing the time and cost of the process, contributing to support informed redesign decisions.

Originality/value
Recently, existing building sustainability assessment (BSA) tools have been adapted and new BSA tools developed for heritage buildings. Some tools target existing buildings, but seldom cover cultural significance and heritage values. Others target the after-redesign situations – aiming at assessing how sustainable the redesign is. Often BSA tools are complex and time-consuming, with extensive indicators and data requirements. The BPSC developed in this research covers the main aspects of sustainability and related heritage values, in a simpler tool for a baseline assessment.

This research applies the theory of planned behaviour (TPB) to measure the gap between designers’ intentions towards heritage conservation and the actual design decisions. It aims at contributing to identify which psychological constructs (attitude, norm, perception of control) are hindering the implementation of sustainable conservation approaches in practice. The results suggest that attitudes have a significant correlation with performed behaviour, and that norms, despite impacting intentions, do not necessarily correlate with the performed actions. Using the TPB to analyse designers' behaviours is an innovative methodological approach that opens new possibilities for the design of interventions targeting behavioural change towards the implementation of sustainable conservation practices in built heritage.