Tamara Surguladze (left) and Natasha Surguladze (right) A celebrity designer and her father have won a court battle with architects over substandard work on their £1.6million home renovation. Natasha Surguladze - one half of identical twin design duo Tata Naka - has been locked in a court fight over unpaid fees with architects Donald Insall Associates. Natasha and her father, businessman Michael Surguladze, commissioned the firm to draw up designs for a 'large scale and unusual project' in Chelsea. The plans involved two adjoining houses being 'effectively demolished' and replaced with a single four-storey double-fronted brick townhouse. The new property was to be home to both Natasha and her father, as well as her twin sister and design partner Tamara, Central London County Court heard. However, the architects and the Surguladzes fell out when design drawings failed to pass building regulations, due to issues with a fire escape and disabled access. The family subsequently obtained the consents they needed and completed the 'large and complicated project' after changing architects. But they were then pursued for £40,000 in unpaid fees by Donald Insall Associates. Now Judge David Saunders has ruled the Surguladzes were right to refuse to pay the architects' bill, as the work had 'not met the required standard'. The Tata-Naka label is the imprint of London-based Georgian identical twins, Tamara and Natasha Surguladze, 40. Fans of the the Central St Martin's graduates' fashion creations include Cameron Diaz, Mena Suvari and Sarah Jessica Parker. Over a decade ago, the twins, who lived together with 'family patriarch' Michael in a mews house in Seymour Walk, Chelsea, decided they needed a bigger living space. But after failing to find a bigger house in a location that suited the family, they decided to buy the house next door to their current home. They then sought permission to knock the two houses through into one, at an estimated cost of £1.6million. They commissioned Donald Insall Associates to create drawings in relation to the planned new house that would pass building regulations. However the submitted design failed to get the green light, with problems relating to fire regulations and disabled access flagged up. Natasha and her father, Michael Surguladze (pictured), commissioned the firm to draw up designs for a 'large scale and unusual project' in Chelsea The family then switched architects, gained consent and have since completed the project, making the house their new home. But Donald Insall Associates later sued them for around £40,000 in unpaid invoices. The architects insisted they should be paid, despite their drawings having failed to pass the regulations. 'The claimant says that it carried out a significant amount of work which in any event should be paid for,' said Judge Saunders. But going on to throw the architects' claim out, he added: 'The plans were of limited value and Building Regulations approval was refused... there has been a consequential lack of care and skill on the part of the claimants. 'I have no doubt that the claimants are - generally - a highly competent and experienced firm of architects, but in this case they have not met the required standard. 'The defendants' instructions to the claimants were to produce plans which would satisfy Building Regulations approval - they did not.' He concluded: 'I find for the defendants and dismiss the claim.' Speaking of the building project in an interview with Harpers Bazaar in 2017, Natasha said: 'It took us 13 years to find our new home. 'We loved our current one and its location, but we needed more space to entertain, more rooms for guests so we looked and we looked and we looked. 'And in the end, after all that looking, we bought the house next door.'All rights reserved for this news site dailymail and under his responsibility