The hearings into the plan, which was sent to the Secretary of State James Brokenshire for consideration in January, will continue until Friday, July 5 and are headed by Inspector Ms Katie Child.
Timescales and venue for the second stage of the hearings will be decided at a later date.
Following the close of the hearings the inspector will prepare a report for the council setting out her conclusions, dealing with broad issues rather than specifically with each individual representation.
The plan, which will shape where thousands of homes and businesses are likely to be built or developed in Calderdale over a 15-year period, has been fiercely argued with the Conservative group in particular expressing concerns.
The Local Plan requires the council to identify sites for around 9,500 new homes in the borough by 2032 – the 12,600 requirement less sites which have already been given planning permission but have not yet been developed.
Craig Whittaker MP said: “Many residents will be aware of the significant concerns that I have in relation to the plan. “We need new housing in all of our communities across the valley but these have to be accompanied by the new roads, schools and health facilities that will make these new developments sustainable.
“Additional development also has to be proportionate to the size of our existing settlements so that local people can accept a reasonable amount of new housing. The current Plan does not meet many of these challenges.”