What grammatical structure is the italicized portion of the sentence? houses should be designed to take advantage of the sun's heat.
a. adverb clause
b. infinitive phrase
c. past participle phrase
d. elliptical clause
e. adjective clause

In the sentence:

Houses should be designed to take advantage of the sun's heat. (guess underlined phrase: to take advantage of the sun's heat). It is an infinitive phrase. Infinitive phrases starts with infinitives that is, “to” added by a simple verb and can be used as nouns, adjectives or adverbs. In the case of including a main clause in the sentence, infinitive phrase separates it with comma

  plan: i will begin with a quotation about the importance of unity in a community. then, i will state my claim that an activity will unite our school by creating a shared vision, purpose, and direction. in the body, i will use three main points that describe the different avenues the students can take: through a variety of clubs, through a special event, or through an awareness week. i will provide evidence about other towns that have unity activities and the kinds of events that they include. pictures will illustrate my three main points in action. for the ending, i will restate the main idea in a new way and pose a question to keep the audience thinking. 

what do you mean.

do we have to write a essay?