Councils spent £45m over the past three years on external legal advice relating to planning appeals, according to a freedom of information request.
The new data found that each local authority spent an average of £45,000 per year on legal advice between 2020/21 and 2022/23.
The Home Builders Federation (HBF), which sent the FOI requests, calculated that this amounted to a national total of £15m a year spent on external advice.
Over the three-year period surveyed, the top 10 councils alone spent £5m, with Medway Council spending the most with a total of £680,000.
Nine of the 10 biggest spenders are in Southern England.
The Planning Inspectorate, an executive agency of the Department for Levelling Up, Housing and Communities, spent £5m on external legal advice relating to planning appeals during this period.