Question

Had he cleaned the house before you reached (change the voice)​

Answer 1

I think this sentence is wrong it shuld be he had cleaned the house before you reached.

Answer 2

Had the house been cleaned by him before you reached?

To change an interrogative sentence into passive voice the following rules must be followed:

1. Interchange the subject with the object and vice versa

2. In case of the verb, use its past participle form

3.  Add ‘by’ before the object

4. The sentence must begin with an auxiliary verb