Home Addition Inspection

Addition foundation must match or exceed existing foundation depth and type. Connection between old and new foundation must be properly engineered.

1. Verify addition foundation type matches existing (depth, width, reinforcement)

2. Check connection between old and new foundation — doweled rebar or engineered connection

3. Inspect for differential settlement — use a level along the junction

4. Check that the footing extends below frost line

5. Verify foundation drainage and waterproofing matches existing

6. Look for cracks at the junction between old and new

7. Check that any existing utilities were properly relocated

- Addition foundation shallower than existing (differential settlement)

- No structural connection between old and new foundation

- Differential settlement causing cracks

- Waterproofing not tied into existing system

- Utilities damaged during excavation

Addition roof must be properly tied into existing roof. Flashing at the junction is critical. Shingles should match existing.

1. Inspect the junction between old and new roofs — flashing must be continuous with no gaps

2. Check for step flashing where addition roof meets existing wall

3. Verify valley flashing if roofs intersect

4. Check that shingles match existing (color, style, brand)

5. Verify gutters are continuous and properly connected

6. Check for proper underlayment at the junction

7. Look for signs of leaks at the interior ceiling near the junction

- Poor flashing at roof junction (most common leak point in additions)

- Shingles not matching existing

- Valley not properly flashed

- Gutters disconnected at junction

- No kick-out flashing where roof meets wall

- Interior ceiling shows water stains near junction

Addition walls must integrate seamlessly with existing. Siding, trim, and interior finishes should match.

1. Check exterior siding match — same material, profile, and color

2. Inspect the junction between old and new siding — should be weathertight

3. Check interior wall connections — should be smooth with no visible joint

4. Verify interior trim matches existing (baseboard, crown, casing)

5. Check that interior paint matches

6. Inspect floor transitions between old and new spaces

7. Verify ceiling heights match

- Siding mismatch visible at junction

- Visible seam between old and new on interior

- Trim styles do not match

- Floor height difference at transition

- Ceiling heights differ

- Paint color mismatch

Electrical, plumbing, and HVAC must be properly extended to the addition. Existing systems must handle the additional load.

1. Verify electrical panel has capacity for additional circuits

2. Check that HVAC was sized for the addition (not just extra duct runs)

3. Test water pressure in addition fixtures — should match existing house

4. Check drain connections — proper slope and venting

5. Verify all connections pass inspection

6. Test heating and cooling in the addition — should reach comfortable temperature

7. Check that exterior utilities (gas, water, sewer) were not damaged during construction

- HVAC not resized — addition is always too hot or cold

- Electrical panel at capacity — no room for addition circuits

- Plumbing pressure drop in existing house

- Drain connections not properly vented

- Utilities damaged during excavation