Town Planning and Housing: Principles, Planned Cities, Neighbourhoods, Densities and Standards

Practice questions (18)

Attempt each one before opening the answer. Every explanation names the tempting wrong option as well as the right one, because that is where marks are lost.

1. Which planning idea rests on a town of limited size set in a permanent agricultural belt, with land held in community ownership and jobs located near homes?

   1. Soria y Mata’s linear city, a continuous urban strip along a transport spine
   2. Le Corbusier’s functional city, with towers in open parkland and functions kept apart
   3. Howard’s garden city, a self-contained town ringed by a permanent agricultural belt
   4. Perry’s neighbourhood unit, a school-centred residential area bounded by arterial roads
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   Answer: C — Howard’s garden city, a self-contained town ringed by a permanent agricultural belt

   Howard’s garden city combines limited size, a permanent agricultural belt, community-owned land and local employment in one self-contained town. The neighbourhood unit is the tempting answer because it is also bounded and compact, but it is a residential area inside a city, with no agricultural belt, no community land ownership and no employment base.

2. Which statement about the layout of Chandigarh is correct?

   1. Its sectors, each roughly 800 m by 1,200 m, are bounded by fast-traffic roads and carry schools, shops and open space inside
   2. Its sectors are long strips along one transport spine, each reached straight from the arterial road with no internal road hierarchy
   3. Its plan was drawn by Walter Burley Griffin around a land axis and a water axis, with an artificial lake as the centrepiece
   4. Its housing is grouped in superquadras of tall slab blocks laid out on the wings of an aeroplane-shaped plan
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   Answer: A — Its sectors, each roughly 800 m by 1,200 m, are bounded by fast-traffic roads and carry schools, shops and open space inside

   Chandigarh’s building block is the sector of about 800 m by 1,200 m, bounded by fast roads and organised inside as a neighbourhood with its own schools, shops and green space, under a seven-level road hierarchy. The land-axis and water-axis plan with a lake is Canberra by Griffin; superquadras on an aeroplane-shaped plan are Brasilia, the tempting mix-up because both are mid-century capitals with superblock housing.

3. Which of the following pairs of city and planner is correct?

   1. Canberra and Pierre Charles L’Enfant, who laid it out around a land axis and a water axis
   2. Brasilia and Lúcio Costa, whose Plano Piloto was chosen for the new capital in 1957
   3. Bhubaneswar and Le Corbusier, who planned the Odisha capital in sectors with a Capitol Complex
   4. New Delhi and Walter Burley Griffin, who laid out the imperial capital on hexagonal geometry
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   Answer: B — Brasilia and Lúcio Costa, whose Plano Piloto was chosen for the new capital in 1957

   Costa’s Plano Piloto (1957) is Brasilia’s plan; Niemeyer designed its principal buildings. L’Enfant planned Washington (1791); Canberra is Griffin’s; Le Corbusier planned Chandigarh, while Bhubaneswar is Königsberger’s; New Delhi is Lutyens and Baker’s. The tempting wrong pair is Bhubaneswar with Le Corbusier, because Chandigarh, the other post-independence capital, is so closely tied to him.

4. Perry’s neighbourhood unit is sized by the population needed to support

   1. a district hospital with its own ambulance service
   2. a weekly market together with a community hall
   3. a place of worship placed at the centre of the unit
   4. one elementary school, which is placed at the centre
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   Answer: D — one elementary school, which is placed at the centre

   Perry sized the unit to the catchment of one elementary school and placed the school, with other institutions, at the centre so that no child walks far or crosses an arterial road. Shops go to the edge, not the centre; hospitals and weekly markets belong to larger tiers of the hierarchy.

5. Which feature most directly characterises the Radburn layout?

   1. A fine gridiron of small blocks so that traffic spreads evenly over a great many streets
   2. A ring of shops and offices round a central square, reached by radial streets
   3. Superblocks with cul-de-sacs, houses facing a park, and pedestrians kept from vehicles
   4. A continuous strip of housing along both sides of a single transit road through the city
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   Answer: C — Superblocks with cul-de-sacs, houses facing a park, and pedestrians kept from vehicles

   Radburn combined the superblock, cul-de-sacs for service access, houses turned to face a park, and complete separation of pedestrians from vehicles. A fine gridiron is the opposite idea, since it admits traffic to every street; the linear strip belongs to Soria y Mata, and the ring around a central square is a radial plan.

6. A planner must (i) keep through traffic out of a housing area, (ii) let children walk to the primary school without crossing a motor road, and (iii) put shops where the adjoining area can also use them. Which scheme meets all three?

   1. A Perry-type unit: arterial boundary, central school reached by internal paths, shops at an edge junction beside the neighbour’s shops
   2. A gridiron of identical small blocks, with shops spread along every street and the primary schools placed on the arterial roads
   3. A Radburn-type superblock whose only shopping street runs through its middle and serves that superblock alone, not its neighbours
   4. A linear strip along a through road, with one school at each end and shops on both sides of that road, open to all passing traffic
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   Answer: A — A Perry-type unit: arterial boundary, central school reached by internal paths, shops at an edge junction beside the neighbour’s shops

   Only the neighbourhood-unit scheme meets all three tests: arterial boundaries divert through traffic, the central school is reached by internal paths, and shops at an edge junction beside the neighbouring unit’s shops serve both. The superblock is tempting because it also keeps traffic out, but a shopping street through its middle serves one superblock only; the gridiron and the through-road strip admit traffic.

7. The same plots and population are kept, but the layout is enlarged by adding parks and roads around them. What happens to the gross and net residential densities?

   1. Gross density rises and net density falls
   2. Gross density falls and net density is unchanged
   3. Both fall in the same proportion
   4. Net density falls and gross density is unchanged
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   Answer: B — Gross density falls and net density is unchanged

   Gross density divides the population by the whole area, which has grown, so it falls. Net density divides it by the residential plots only, which have not changed, so it is unchanged. The claim that net density falls and gross density stays put reverses the roles: adding roads and parks cannot lower the density measured over the plots alone.

8. Two housing schemes have the same gross density of 250 persons per hectare. In scheme X, 60% of the land is residential plots; in scheme Y, 40%. Which has the higher net density, and what are the net densities?

   1. Scheme X, at about 150 pph against about 100 pph for Y
   2. Scheme X, at about 625 pph against about 417 pph for Y
   3. Both schemes at 250 pph, because the gross densities are equal
   4. Scheme Y, at about 625 pph against about 417 pph for X
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   Answer: D — Scheme Y, at about 625 pph against about 417 pph for X

   Net density = gross density ÷ plot share. For X: 250 ÷ 0.6 ≈ 417 pph; for Y: 250 ÷ 0.4 = 625 pph. Y, which gives less land to plots, must pack more people on each plotted hectare to reach the same gross figure. Multiplying by the share instead of dividing (150 and 100) is the usual slip and would even make net lower than gross.

9. In facility planning, “threshold population” means

   1. the largest population a single facility can serve without becoming overcrowded
   2. the walking distance within which a user is expected to reach the facility
   3. the smallest population whose demand makes the facility viable to provide
   4. the land area allotted to the facility for every 1,000 persons served
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   Answer: C — the smallest population whose demand makes the facility viable to provide

   The threshold is the minimum population needed to justify a unit. The walking distance is the service radius or catchment, a different test; the area per 1,000 persons is an area norm; and the largest population a facility can serve is its capacity, not its threshold.

10. A housing scheme is proposed on a hillside of moderate slope with good views, seasonal streams and a road along the upper edge. Which layout response best fits the site?

    1. Terraced clusters on the contours, access lanes along them, streams kept free for drainage, retaining works where needed
    2. Level the whole hillside by deep cutting and filling so that a regular gridiron of equal plots can be laid out across it
    3. Place long slab blocks across the slope to give every flat a view and to shorten the length of road needed
    4. Divert the seasonal streams into pipes beneath the plots so that the whole slope can be built at plains density
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    Answer: A — Terraced clusters on the contours, access lanes along them, streams kept free for drainage, retaining works where needed

    On a slope the layout should follow the land: contour-aligned terraces and lanes need little cut and fill, keep natural drainage lines open and spread the load on the hillside. Levelling creates unstable cut faces; slabs across the slope block drainage and cause heavy cut and fill; piping streams under plots invites flooding and failure, and plains density is unsuitable on a slope.

11. Which of the following are ideas of the Radburn layout? Select all that apply.

    1. Houses turned so that living rooms and gardens face a park
    2. A continuous line of shops along every residential street
    3. Complete separation of pedestrian and vehicular traffic
    4. Superblocks served by cul-de-sacs in place of small gridiron blocks
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    Answer: A — Houses turned so that living rooms and gardens face a park; C — Complete separation of pedestrian and vehicular traffic; D — Superblocks served by cul-de-sacs in place of small gridiron blocks

    The Radburn idea has five parts: superblock, specialised roads, complete pedestrian–vehicle separation, houses turned to the park, and the park as backbone. A continuous line of shops along every residential street contradicts it, since it would bring vehicles and customers to the front of every home.

12. Select the correct statements about planned cities.

    1. Navi Mumbai was developed by CIDCO as a counter-magnet to divert growth from Mumbai
    2. Washington’s 1791 plan by L’Enfant laid baroque diagonal avenues over a street grid
    3. Canberra was laid out by Le Corbusier as a city of sectors around a Capitol Complex
    4. Jaipur was laid out in 1727 by Sawai Jai Singh II as a walled city of nine blocks
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    Answer: A — Navi Mumbai was developed by CIDCO as a counter-magnet to divert growth from Mumbai; B — Washington’s 1791 plan by L’Enfant laid baroque diagonal avenues over a street grid; D — Jaipur was laid out in 1727 by Sawai Jai Singh II as a walled city of nine blocks

    Navi Mumbai (CIDCO, counter-magnet), Washington (L’Enfant, diagonals over a grid) and Jaipur (Jai Singh II, 1727, nine blocks) are correctly described. Canberra is the work of Walter Burley Griffin and Marion Mahony Griffin around land and water axes; the sector city around a Capitol Complex is Chandigarh, which is where this wrong statement borrows from.

13. Which of the following belong to Perry’s neighbourhood unit?

    1. The unit is bounded by arterial streets so that through traffic goes round it
    2. The local shops are placed in the middle of the unit, beside the school
    3. Arterial roads run through the centre so that customers reach the school easily
    4. The size of the unit is set by the population that supports one elementary school
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    Answer: A — The unit is bounded by arterial streets so that through traffic goes round it; D — The size of the unit is set by the population that supports one elementary school

    Perry bounded the unit by arterials and sized it by one elementary school’s population. His local shops sit at the edge, at traffic junctions, not in the middle, and arterial roads are kept out of the centre, since the school and children’s paths are protected from through traffic.

14. Select the correct statements about residential density.

    1. Persons per room is a measure of the density of land
    2. For a given layout, net density is never lower than gross density
    3. Gross density counts roads, open space and facilities in its area
    4. At a fixed number of persons per plot, doubling the plots per net hectare doubles the net density
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    Answer: B — For a given layout, net density is never lower than gross density; C — Gross density counts roads, open space and facilities in its area; D — At a fixed number of persons per plot, doubling the plots per net hectare doubles the net density

    Net density divides by the smaller, residential-only area, so it is never lower than gross; gross density divides by the whole layout; and at a fixed number of persons per plot, net density is proportional to plots per net hectare. Persons per room measures crowding inside dwellings, not the density of land, which is the usual confusion.

15. A rectangular sector of 800 m by 1,200 m houses 19,200 persons. Its gross density, in persons per hectare, is ____.

    Numerical answer — type the value.

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    Answer: 200

    Area = 800 × 1,200 = 960,000 m² = 96 ha (1 ha = 10,000 m²). Gross density = 19,200 ÷ 96 = 200 persons per hectare. Check: 96 × 200 = 19,200.

16. A neighbourhood of 50 ha houses 15,000 persons, and 40% of its area is under residential plots. Its net residential density, in persons per hectare, is ____.

    Numerical answer — type the value.

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    Answer: 750

    Net residential area = 0.40 × 50 = 20 ha. Net density = 15,000 ÷ 20 = 750 persons per hectare. The gross density, 15,000 ÷ 50 = 300, is the trap; net = gross ÷ 0.4 = 750 agrees.

17. A group-housing site has a net plot area of 2 ha and a FAR of 1.5. Of the floor area, 20% is common circulation and services and the rest is in dwellings of 60 m² each, with 4.5 persons per dwelling. The net density, in persons per hectare of plot, is ____.

    Numerical answer — type the value.

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    Answer: 900

    Plot = 20,000 m²; floor area = 1.5 × 20,000 = 30,000 m². Dwelling floor = 0.8 × 30,000 = 24,000 m²; dwellings = 24,000 ÷ 60 = 400; persons = 400 × 4.5 = 1,800. Net density = 1,800 ÷ 2 = 900 persons per hectare. Ignoring the 20% would give 1,125.

18. A layout is planned for 36,000 persons. The assumed norm is one primary school for every 5,000 persons, on a site of 0.4 ha, and only whole schools are provided (round the number up). The total school land, in hectares, correct to one decimal place, is ____.

    Numerical answer — type the value.

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    Answer: 3.2

    Schools = 36,000 ÷ 5,000 = 7.2, rounded up to 8 whole schools so that no catchment exceeds the norm. Land = 8 × 0.4 = 3.2 ha. Using 7.2 directly would give 2.88, the trap of not rounding the unit count.