Barry O'Sheefe of West Ryde Builders Pty Ltd (hereinafter referred to as "the Builder") was engaged by Tom and Amelia Smith (hereafter referred to as "the Owners") to quote on the construction of a six bedroom house onthe Owners' land at Lot 43, Roseville Terrace Glenmore Park. The Builder and the Owners had a meeting on 19 March 2020 to discuss their requirements.

The Owners said: "We have elderly parents who will be living with us and we require disabled toilets and wider doors for access".

The Builder said: "No problem this will be included".

The Owners paid the Builder $4,000.00 for the Builder's draughtsman to prepare the plans, lodge them at Penrith City Council and obtain an approval. On 4 April 2020, the Owners had a meeting with John Patterson from Prestige Drafting.

The Owners said: "We like the plans and they seem to incorporate everything we discussed with the Barry".

John Patterson said: "Yes, I've incorporated everything you wanted".

The plans were lodged at Penrith City Council on 27 April 2020 and approved on 14 May 2020. On 16 May 2020, the Owners signed a Housing Industry Association New South Wales Residential Building Contract for New Dwellings at a Contract price of $395,000.00 and paid the Builder a deposit of $60,000.00. The Builder commenced work on the house on 2 June 2020.

On 6 June 2020, the Owners requested the rumpus room be extended by 1.5 metres.

Barry said: "No problem" and nothing else was discussed regarding the cost of the variation.

On 15 June 2020, the Owners discovered the toilets were not disabled toilets and the doors were not wide enough for access by their parent's wheelchair. The Builder has given the owners, a claim for the extra 1.5 metres in the rumpus room of $42,300.00 and a first progress payment claim of $63,000.00.

Answer this question: Advise Mr and Mrs Smith of their rights.