Lake Hayes resident Fred van Brandenburg opposed the latest land use and subdivision consents applied for by Meadow 3 Ltd during the public hearing in August.
The hearing decisions released this month by commissioners John Matthews and Cath Gilmour were contrary to his initial agreement, Mr van Brandenburg said.
"There's no protection mechanism for [Meadow 3] not to cut the trees down again . . . One of the most famous scenes in New Zealand will be lost forever."
Mr van Brandenburg said the Environment Court agreed with his concerns before and no doubt would agree with him again.
The commissioners decided the proposed alterations to historic buildings on the 200ha Threepwood property would be publicly notified on a date to be confirmed.
Consent was sought by Meadow 3 to convert the 19th century homestead and woolshed to a lodge and day spa, including additions and alterations to both buildings.
Mr Matthews and Ms Gilmour said they were concerned over the proposed shifting of the homestead front door from the north end of the veranda to the centre and the additions of two conservatories.
They described the alterations as "significant changes to a heritage building" that were not included in the 1998 application, which led to the consent order; and they were not on the plans.
Meadow 3 co-director Jim Boult, of Lake Hayes, said he was generally quite happy with the decisions and the conditions were what he thought they would be.
Next steps would be decided if there was an appeal.
The commissioners granted with conditions the three other Meadow 3 consents.
The developer was allowed to shift the 1930s manager's house from its present location, carry out landscaping works around the historic homestead known as the Lodge, construct two visitor car parks and carry out earthworks.
Meadow 3 was allowed to adjust the boundaries of lots 15 to 19 and lot 21 and move the building platforms on lots 16 to 19.
It was permitted to undertake earthworks and vary conditions of an earlier resource consent to allow for further landscaping.
Approval was given for the design and location of 10 cottages, which were already consented.
