Question: What is the main focus of both paragraphs?

full_context: Document 1: Public School No. 109: Public School No. 109, also known as Male and Female Primary School No. 5 and Broadway School, was a historic elementary school located at Baltimore, Maryland, United States. It was a two story red brick utilitarian building featured a central tower capped by a pediment, two large chimneys with arched openings, and an entrance appendage on the south façade housing a stairwell. It was constructed in 1876 as an "open plan" school with classes separated by glass partitions. It was demolished in late 2003/early 2004 in order to make room for the Kennedy Krieger Institute’s new “Community Behavioral Health Center.”
Document 2: East Springfield Union School: East Springfield Union School, also known as Springfield Central School, is a historic school building located at East Springfield in Otsego County, New York. It was built in two stages, starting in 1909. The original front section is a two story, "T" plan, cross gabled Neoclassical style building executed in rusticated concrete block and set on a half raised basement. The rear portion is a single story utilitarian concrete block structure built in 1936. The main facade includes a protruding, full height central gable, its pediment featuring an Adamesque lunette window, fishscale slates, and a heavy wood cornice. The school closed in 1989.
Document 3: Central Michigan University: Central Michigan University (CMU) is a public research university located in Mount Pleasant in the U.S. state of Michigan. Established in 1892, Central Michigan University is one of the largest universities in the state of Michigan and one of the nation's 100 largest public universities. It has more than 20,000 students on its Mount Pleasant campus and 7,000 students enrolled online at more than 60 locations worldwide.
Document 4: Schoolfield School Complex: Schoolfield School Complex is a complex of historic school buildings located at Danville, Virginia. The complex consists of Building A, built in 1912 or 1913, Building B, built in 1936 or 1937, and Building C, built in 1939 or 1940. Building A is a 2 1/2-story, Prairie School style brick building with deep eaves that cap a narrow elongated structure, multi-paned massed windows, and horizontal masonry banding. It has an entry tower and addition built in 1933. Building B is a vernacular brick building that operated as a vocational center. Building C is a one-story, brick Colonial Revival style elementary school building. It was originally built as a Public Works Administration project and housed Schoolfield High School. The complex was built by the Riverside & Dan River Cotton Mill Company as part of the mill worker neighborhood called “Schoolfield Village.”
Document 5: Carnegie Mellon University: Carnegie Mellon University (Carnegie Mellon or CMU or ) is a private research university in Pittsburgh, Pennsylvania.
Document 6: Old District 10 Schoolhouse: Old District 10 Schoolhouse, sometimes referred to as the Little Red Schoolhouse, is a 5-room former schoolhouse located in Middleburg Heights, Ohio. Built in 1912, the building was the site of Middleburg's first city hall, as well as a speakeasy during Prohibition and a railroad way station. It was then bought by Harvey Cross in 1940 and was used as his private home until his death in 1970.
Document 7: William Shelly School and Annex: William Shelly School and Annex, also known as Eberton School, is a historic school building and annex located at West York, York County, Pennsylvania. The building known as Shelly Annex was built about 1897 as a one-room school. It was enlarged twice between 1898 and 1903, to be a 2 1/2-story, gable roofed brick building, three bays wide and seven bays deep. The Shelly School was built between 1905 and 1908, in the Italian Renaissance style. It is a two-story brick building, nine bays wide and seven bays deep. It was completely rebuilt after a fire in 1919. The property was sold in 1960, and the buildings utilized as storage facilities for the next 37 years.
Document 8: Dymaxion deployment unit: A Dymaxion deployment unit (DDU) is a structure designed in 1940 by Buckminster Fuller consisting of a 20-foot circular hut constructed of corrugated steel looking much like a yurt or the top of a metal silo. The interior was insulated, finished with wallboard, portholes and a door. The dome-like ceiling has a hole in the top and a cap for ventilation.
Document 9: Horace Mann School (Schenectady, New York): Horace Mann School, also known as Craig Street School, is a historic school building located at Schenectady, Schenectady County, New York. It was built in 1907-1908, and is a two-story, "I"-shaped brick building above a reinforced concrete basement. The building includes some Neoclassical design elements including large fanlights, a projecting modillioned cornice, and monumental corner pilasters. A one-story rear addition was constructed in 1986. The Horace Mann School closed in 1981. The building is identical to the former Franklin School, listed on the National Register of Historic Places in 1983.
Document 10: Concrete masonry unit: A concrete masonry unit (CMU) is a standard size rectangular block used in building construction.
Document 11: Old Huntington High School: Old Huntington High School is a historic high school building located at Huntington, Cabell County, West Virginia. It was built in 1916, and is a 4 1/2 story buff brick building in the Classical Revival style. It consists of a long rectangle with a shorter rectangular wing on each end of the main rectangle forming a "U" shape. The courtyard is enclosed with three additions completed in 1951 (gymnasium), 1956 (cafeteria), and 1977. The building contains 155,512 sqft of space. The kitchen is located in an older red brick building built in 1916, built originally as a carriage house. The last graduating class was in 1996. A new facility was constructed and opened in the fall of 1996, known as Huntington High School. It is now known as The Renaissance Center. Part of the building was converted into apartments. The YMCA uses part of it for workout facilities and a daycare facility. The building also houses studio space, an auditorium, and small art gallery.
Document 12: Concrete plant: A concrete plant, also known as a batch plant or batching plant or a concrete batching plant, is equipment that combines various ingredients to form concrete. Some of these inputs include water, air, admixtures, sand, aggregate (rocks, gravel, etc.), fly ash, silica fume, slag, and cement. There are two main types of concrete plants: "Dry mix" plants and "Wet mix" plants, and also plants that contain both a transit mix side and a central mix side while utilizing common material storage points. A concrete plant can have a variety of parts and accessories, including: mixers (either "tilt drum" or "horizontal" or in some cases both), cement batchers, aggregate batchers, conveyors, radial stackers, aggregate bins, cement bins, heaters, chillers, cement silos, batch plant controls, and dust collectors.
Document 13: Cliffside Public School: Cliffside Public School is a historic school complex located at Cliffside, Rutherford County, North Carolina. It was designed by noted architect Louis H. Asbury (1877-1975) and built in 1920-1921. It is a two-story on basement, "T"-plan, Classical Revival style terra cotta tile building sheathed in glazed brick. The front facade features a tetrastyle two-story portico of Indiana limestone. The vocational and physical education building, erected by the Work Projects Administration in 1940-1941. Also on the property are the contributing series of fieldstone masonry structures built in 1940-1941.It sits on landscaped grounds designed by Earle Sumner Draper.
Document 14: Tower block: A tower block, high-rise, apartment tower, residential tower, apartment block, block of flats, or office tower is a tall building or structure used as a residential or office building. In some areas it may be referred to as an "MDU", standing for "Multi Dwelling Unit". In the United States, such a structure is referred to as an apartment building or office building, while a group of such buildings is called an apartment complex or office complex.
Document 15: Tilt up: Tilt-up, tilt-slab or tilt-wall is a type of building and a construction technique using concrete. Though it is a cost-effective technique with a shorter completion time, poor performance in earthquakes has mandated significant seismic retrofit requirements in older buildings.
ground_truth: building construction.