The Planning Act could cost councils in Scotland up to £59m over the next 10 years in new burdens.
RTPI (Royal Town Planning Institute) Scotland has published research that suggests 49 new and unfunded duties will be imposed on authorities as a result of the legislation.
The cost has been calculated at between £12.2m and £59.1m while the planning workforce may need to increase by as much as 9.4% to maintain a ‘business as usual’ service.
RTPI found that planning authorities’ budgets have decreased in real terms by more than 40% and staff numbers have been cut by a quarter since 2009.
RTPI Scotland convenor Julia Frost said: ‘This analysis shows that we need significant investment in planning services just to make sure that they comply with the law.
'This, combined with the fact that planning has suffered budget cuts more severely than other local government functions, means that we need an open and honest debate on how we resource planning services in the future.’
The report said that the intention was to offset the costs of the Act through savings from abolishing strategic planning and extending local development plans from five to 10 years.
RTPI has instead called for the Scottish Government to look to cover the costs of the new duties in a future spending review and ensure any revenue generated from planning applications is reinvested in the planning service.
Ms Frost added: ‘If we don't give planners the time and resources to process planning applications and proactively create plans for the future we won't be able to build new homes, regenerate our town centres or protect our most valuable landscapes and buildings.’
A Scottish Government spokesman said the research was ‘unhelpful speculation’ on how the Act will work in practice.