UKIP gained 163 council seats in last month's vote, with a particularly strong showing in south Essex, where it gained a total of 26 seats in Southend, Castle Point, Basildon and Thurrock councils.
The four councils, all of which were Tory-held apart from Labour-controlled Thurrock, have now moved to no overall control as a result of UKIP's gains.
The biggest gain came in Basildon, where the party won 11 seats to become the official opposition with 12 seats. UKIP group leader Kerry Smith said a Tory minority administration was the most likely scenario.
He said a key reason for the Tories losing support was a controversial plan for 725 homes on the Dry Street wildlife haven. Although the plan won outline approval last June, Smith said UKIP still hoped to "defeat" it.
He said: "This idea of build, build, build on the green belt is not going to solve anything while we are members of the EU and have to endure uncontrolled immigration."
Plans for new homes on the green belt was also a key campaign issue in neighbouring Castle Point, where UKIP won five seats. Alan Bayley, Castle Point Council's UKIP group leader, said the party had rejected a request to back a Tory administration.
He said: "We are totally anti-new homes on the green belt. Regarding the local plan, we would demand all brownfield sites are exhausted before any other land is even considered."
UKIP's local election manifesto promises to "protect our green spaces by directing new developments to brownfield sites". It criticises the government's "mass housebuilding" as a "developers' charter" and pledges to subject major planning decisions to "binding local referendums".
Ron Woodley, leader of Southend Council's 13-strong independent group, said the plan was to form a "partnership" with the council's Lib Dem and Labour groups under his leadership. Though UKIP, which won five seats, would not be part of the coalition, he said he would involve the party as much as possible.
In Thurrock, where UKIP gained five seats, a minority Labour administration is expected.
Tom Curtin, chief executive of planning engagement consultancy Curtin&Co, said: "At the local level, (UKIP's support) has been partly driven by a deep resentment of the planning process and a determination to see development halted altogether in people's back yards.
"UKIP is the only party with an essentially anti-development policy. There is no doubt it will wield influence where it has a substantial minority."
But Curtin pointed out that UKIP had not managed to take control of any single council or planning committee and, even in power, the party would have to comply with the government's pro-housing growth planning policies.
Nick Jones, head of strategic communications at property consultancy GL Hearn, said it was unlikely UKIP would be part of any administration in the authorities concerned. He said the need for a local plan would remain, regardless of political control and the change would not make a "massive difference".
James Anderson, head of engagement at consultancy Turley, said UKIP's opposition to "excessive" housing development, wind farms and HS2 would be "concerning" for the property industry and a "challenge" for planners.
LABOUR'S CAPITAL GAINS
Labour has pledged to reform the "broken" planning process in the formerly Tory London borough of Hammersmith and Fulham, after the party made gains in the capital.
Labour gained control of the borough, as well as Croydon, from the Conservatives and Merton and Redbridge from no overall control. The Tories, meanwhile, gained control of Kingston Council from the Lib Dems.
Among Labour's manifesto promises in Hammersmith and Fulham is an immediate review of "contentious developments" by a new contracts unit. It mentions six major schemes "rushed through" by the Tories, including the redevelopments of Earls Court and Shepherds Bush market.
The party promises to use planning powers "to ensure new homes built in the borough go to residents and are not marketed as investment units" and to reintroduce a minimum requirement for affordable homes.
It also wants to set up "ward panels", involving residents, businesses and councillors, which would be involved in any pre-application discussions involving developers and officers. Meanwhile in Croydon, Labour's manifesto has promised a minimum 30 per cent affordable housing requirement and to review the town centre's Community Infrastructure Levy provision and its "mega tower policy".