Here's one version of my non-combat awards chart. Note these awards are in addition to standard monster xp awards. Obtaining a Tier 1 treasure hoard without combat might be a Tier 1 moderate award, 50 XP per PC.
Low Level (Tier 1) XP awards (per PC)
Easy Achievement: 10 XP (Challenge 0)
Minor Achievement: 25 XP (Challenge 1/8)
Moderate Achievement: 50 XP (Challenge 1/4)
Major Achievement: 100 XP (Challenge 1/2)
Very Hard Achievement: 200 XP (Challenge 1)
Exceptional Achievement: 450 XP (Challenge 2)
Mid Level (Tier 2) XP awards (per PC)
Easy 50 XP (Challenge 1/4)
Minor 100 XP (Challenge 1/2)
Moderate 200 XP (Challenge 1)
Major 450 XP (Challenge 2)
Very Hard 700 XP (Challenge 3)
Exceptional 1100 XP (Challenge 4)
High Level (Tier 3) XP awards (per PC)
Easy 200 XP (Challenge 1)
Minor 450 XP (Challenge 2)
Moderate 700 XP (Challenge 3)
Major 1100 XP (Challenge 4)
Very Hard 1800 XP (Challenge 5)
Exceptional 2300 XP (Challenge 6)
Epic Level (Tier 4) XP awards (per PC)
Easy 700 XP (Challenge 3)
Minor 1100 XP (Challenge 4)
Moderate 1800 XP (Challenge 5)
Major 2300 XP (Challenge 6)
Very Hard 2900 XP (Challenge 7)
Exceptional 5000 XP (Challenge 8)
XP awards tend to increase over time, as the scale of achievements increase.
Acquiring significant
Treasure is usually worth some XP, as is rescuing prisoners, infiltrating a guarded keep, exploring a cavern network, etc. A typical major session award for non-combat achievements might be 25 XP per PC at level 1, rising to ca 100 XP per PC at level 4.