As far as i understand it, according to the the NAO report, TCE have differing obligations as determined by the type of lease/tenancy
For Forest Lodge, they have repair responsibility for short term leases, for long term leases on AMW's property or that of the Edinburghs, this is different
Re FL,TCE accepted a repair liabilty (as per the lease and the NAO) for the FL 'compound' of £400k after the relinquised tenancy. The £400k is across 4 different buildings - £230k on FL and about £45k each on the other buildlings
Lease terms and types: Within the six leases we reviewed, the length of lease varied significantly. Forest Lodge, recently leased, is on a 20-year short-term lease with quarterly rent payments and no upfront deposit. This is due to
The Prince and Princess of Wales paying for all the internal refurbishments as is TCE’s standard practice for leases of 20 years. Forest Lodge’s comparator property is leased on a two-year short-term lease with an upfront deposit, and TCE responsible for the costs of all internal refurbishments. The other long-term leases range in term from 70 to 150 years, all requiring an upfront premium payment, with either an annual ground rent (Thatched House Lodge) or peppercorn rent (Royal Lodge, Bagshot Park and comparator property).
Repair and refurbishment costs: The six properties at the time of leasing were in different states of repair and required different levels of investment.
In 2003, Royal Lodge needed significant refurbishment estimated to cost
£5 million. As the lease was signed, Andrew Mountbatten-Windsor agreed
to spend £7.5 million on improvements. Eclipse Nominees Limited (Bagshot Park) and Princess Alexandra (Thatched House Lodge) also both committed to funding initial repairs and improvements. A minimum spend of £10,000 was committed to as part of the lease terms for Thatched House Lodge in 1971. Eclipse Nominees held a lease for Bagshot Park from 1998 to 2007, which committed a restoration spend of £1.38 million. TCE is responsible for funding the renovation costs on short-term leases. Prior to The Prince and Princess of Wales moving into Forest Lodge, TCE paid around £400,000 to repair Forest Lodge, the three cottages and property grounds in line with their obligations as landlords
The NAO report references the PPoW having a licence waiver re their rental agreement to make their own renovations (paid for by themselves)