Reb Chaim discusses a distinction between matzah made from wheat (or the five grains) and the need for it to be considered halachic “bread” and shows that both are necessary for matzah.

Reb Chaim explores whether the mitzvah of burning chametz is a requirement to actively destroy chametz or is fulfilled by passively not having chametz in your property

Reb Chaim analyzes whether the second day of Yom Tov observed in exile after the calendar was set is kept as a safeik (doubtful obligation) or a definite day of Yom Tov.

Reb Chaim analyzes whether bein hashemashos (the period between sunset and nightfall) is uncertain what moment day turns into night or is an inherent safeik, composed of both day and night.

Reb Chaim explains that an Eruv does not need walls, but rather the space needs to be enclosed, and we connect this with a similar ruling in the laws of Chanukah

Reb Chaim analyzes the concept of a 'doorway' in the halachos of Succah and Eruvin, and evaluates what makes something an opening versus a breach in a wall and whether a doorway is halachically defined as wall or different.

Reb Chaim explains an unusual Rambam by contextualizing that the Rambam is not discussing the measurements of a Reshus Hayachid, as commonly understood, but is discussing how different domains affect each other.

Reb Chaim analyzes the dimensions of the reshus hayachid (4 by 4 tefachim wide), and discusses two elements to this condition.