Key legal question
Whether the landlord's signed building application limited the tenants' compensation for added value to CHF 10,000
Extracted holding
No. The signed form only expressed consent to the pool construction; it did not objectively cap compensation or set a price limit.
Extracted reasoning
Applying the trust principle, the form was an administrative request stating an approximate construction cost, not a contractual cap. The tenants could in good faith understand the landlord to consent to the pool despite the low estimated cost.