But Pace Farm, which owns the Parkwood estate in west Belconnen, would not confirm on Tuesday whether the chickens had been destroyed.

The ACT government agreed to purchase a 24-hectare subdivision of the property last year if Parkwood Egg Farm ceased cage farming and converted to barn operations.

There was an attack on the property in March last year, in which conveyor belts were slashed and equipment was destroyed.

As part of its deal with the ACT government, Pace Farm has been given nearly four years to convert the facility to barn eggs.

The government said on Tuesday it made a $3.75 million payment to Pace Farm in November last year.

Economic Development Minister Andrew Barr said the second and final payment of $3.75 million would ''only be made when the conversion of the facilities has reached a stage deemed acceptable to the territory''.

The government has given Pace 42 months to convert the facility.

Former Greens MLA Caroline Le Couteur, who pursued a territory-wide ban on cage egg production in the Legislative Assembly, said on Tuesday Pace Farm had been given a ''generous deal'' when legislation to stop cage farming was due to be tabled in the Assembly this year.

Pace Farm did not answer questions on Tuesday about when it planned to convert the site to barn operations, nor did it respond to questions about what had happened to the chickens that were on the site at the time of last year's attack.

The Canberra Times understands that Parkwood Farm was destocked and the site used as a packing facility for eggs from interstate.

At the time of last year's raid, about 30,000 chickens were at the farm.

RSPCA ACT chief Michael Linke said on Tuesday laying hens had a life span of just 12 to 18 months and were typically destroyed when a property was destocked.

''Once they reach the end of their laying life they're destroyed,'' Mr Linke said. ''That's what happens when farms are destocked - they're humanely killed.''

Legislation to ban factory farming is part of the ACT Greens parliamentary agreement with ACT Labor and is due to be tabled in spring.

The legislation will be based on an earlier bill from Ms Le Couteur, who said on Tuesday she was concerned the ACT government's $7.5 million agreement with Pace Farm was ''purely a real estate deal''.

The ACT government will eventually rezone and sell the land for industrial use.

Mr Barr said the agreement placed strict obligations on Pace to operate the facility to barn egg production standards and the government could inspect the site.

The value of the land was expected to be ''significantly more than $7.5 million once it is rezoned for sale for industrial use''.

''The government's primary objective was to end the practice of cage egg farming in the ACT whilst supporting employment and investment in primary production,'' Mr Barr said.

He said the government had inspected the property in June and was satisfied with the progress of the work.