Key legal question
Whether the disputed garden and property expenses were deductible maintenance costs or partly non-deductible value-enhancing costs.
Extracted holding
The taxpayers did not prove the share of deductible maintenance costs. The authority's 60/40 estimate was acceptable.
Extracted reasoning
The invoices showed extensive garden works, but they did not reliably distinguish maintenance from value enhancement. Mixed expenses may be estimated; without further evidence the authority's estimate could not be criticized.