The present technology is generally directed to horizontal heat recovery and non-heat recovery coke ovens having monolith components. In some embodiments, an HHR coke oven includes a monolith component that spans the width of the oven between opposing oven sidewalls. The monolith expands upon heating and contracts upon cooling as a single structure. In further embodiments, the monolith component comprises a thermally-volume-stable material. The monolith component may be a crown, a wall, a floor, a sole flue or combination of some or all of the oven components to create a monolith structure. In further embodiments, the component is formed as several monolith segments spanning between supports such as oven sidewalls. The monolith component and thermally-volume-stable features can be used in combination or alone. These designs can allow the oven to be turned down below traditionally feasible temperatures while maintaining the structural integrity of the oven.