The case concerned an unusual “vertical” boundary issue between a first‑floor flat owner (the petitioner) and the second‑floor owner above (the respondent). The disagreement centred on who owned — and therefore controlled — a narrow void space running between the two properties.

The void in question sits above the petitioner’s bathroom and passes up into the respondent’s flat. The arbitrator split this space into two parts:

• Intermediate Area — the space directly above the first‑floor bathroom ceiling
• Lightwell Area — the higher section running up towards the roof

The arbitrator concluded that the petitioner only owned the Intermediate Area. The boundary between the two areas lay at the centre line of the joists supporting the respondent’s floor. As a result, the petitioner had no ownership, sole or shared, of the Lightwell Area, meaning the question of encroachment did not arise.

The petitioner argued that the arbitrator:

• Misapplied Scots property law
• Failed to explain why he preferred one legal interpretation over another
• Ignored relevant case law
• Wrongly limited the petitioner’s ownership based on a 1968 sasine deed
• Misunderstood section 3 of the Tenements (Scotland) Act 2004, which the petitioner said allowed for a broader interpretation of what forms part of a flat

Because the respondent opposed the appeal, the petitioner needed permission (“leave to appeal”) from the court.

Lord Lake, sitting in the Outer House, refused permission to appeal. He found no “obvious error” in the arbitrator’s reasoning.

On the use of historic evidence to interpret title deeds, he said the arbitrator’s approach reflected established law: deeds are interpreted based on their meaning at the time they were signed, not on later events.

He also rejected the argument that the 2004 Act changed how deeds should be interpreted, noting that the Act deals with what can be pertinent of a flat, not how titles themselves are read.

A key part of the arbitrator’s reasoning was the curtain principle — the rule that, when interpreting a Land Register title, only certain prior sasine deeds can be considered.

The arbitrator held that only the respondent’s prior sasine title could be looked at, not the petitioner’s. That meant the 1968 deed relied on by the petitioner was irrelevant.

Lord Lake noted that the petitioner had not challenged this part of the award, and once accepted, it effectively removed the 1968 deed from the equation entirely.

Having found no legal error, Lord Lake refused the application for leave to appeal. The arbitrator’s decision therefore stands.