Housing and slum redevelopment

In short

Housing and slum redevelopment is the branch of urban planning that quantifies how many dwellings a city needs, for whom and at what price, and then plans the upgrading, redevelopment or relocation of informal settlements. It matters because Census 2011 recorded 1.37 crore slum households — about 65.5 million people, 17.4% of India's urban population, in 2,613 of 4,041 statutory towns — while the Technical Group (TG-12) put the 2012 urban housing shortage at about 1.88 crore units, over 95% of it in the EWS and LIG groups. The topic is examined in B.Plan housing and urban planning papers and in GATE Architecture & Planning (Part B, Planning) under housing, housing policy and programmes. It is used daily by town planners, planning consultants, ULB and development-authority staff, slum boards (SRA Mumbai, DUSIB Delhi, TNUHDB), and by developers preparing redevelopment schemes.

Explained

Housing: definitions, classifications and the shortage estimate

• Dwelling unit (DU): an independently accessible living space for one household. Household: persons who normally live together and eat from a common kitchen (Census definition).
• Income categories (PMAY-U 1.0): EWS up to ₹3 lakh annual household income (carpet area up to 30 m²), LIG ₹3–6 lakh (up to 60 m²), MIG-I ₹6–12 lakh (up to 160 m² after the 2017 revision), MIG-II ₹12–18 lakh (up to 200 m²). PMAY-U 2.0 (2024) uses EWS up to ₹3 lakh, LIG ₹3–6 lakh, MIG ₹6–9 lakh — verify the current mission guidelines, as limits and carpet-area caps have been revised more than once.
• Tenure classification: ownership, rental (formal and informal), employer/institutional housing, and informal occupation without legal title.
• Components of housing shortage: (i) net new household formation, (ii) congestion — households sharing a dwelling or living in one-room units with high occupancy, (iii) obsolescence — dilapidated/non-serviceable kutcha stock needing replacement, (iv) vacancy reserve (typically 2–4%) to allow mobility, (v) homeless households.
• A paradox the TG reports highlight: India has both a large shortage and a large stock of vacant houses (about 1.1 crore vacant urban houses in Census 2011) — the shortage is of *affordable, well-located* housing, not of built area in general.
• Affordable housing (infrastructure-status definition, 2017): 60 m² carpet area for MIG/LIG projects; for GST the concessional 1% rate (without input tax credit) applies to residential units up to 60 m² carpet in metros / 90 m² in non-metros and value up to ₹45 lakh, other residential units at 5% without ITC — the September 2025 GST slab restructuring (5/18/40) did not alter these scheme-specific real-estate rates, but confirm the current notification.

What a slum is, legally and statistically

• Slum Areas (Improvement and Clearance) Act, 1956 (Delhi and adopted by several states): a slum is an area where buildings are unfit for human habitation, or are by reason of dilapidation, overcrowding, faulty arrangement of streets, lack of ventilation, light or sanitation detrimental to safety, health or morals. Declaration is by a competent authority by notification.
• Census of India three-fold definition:
  1. Notified slum — notified under any Act, including the Slum Act.
  2. Recognised slum — recognised as a slum by the State/UT, ULB or housing/slum board but not formally notified.
  3. Identified slum — a compact area of at least 300 population or about 60–70 households of poorly built, congested tenements in an unhygienic environment, usually with inadequate infrastructure and lacking proper sanitary and drinking-water facilities.
• Why the distinction matters: eligibility for most schemes, for tenure and for compensation historically followed notification, so non-notified settlements are the most vulnerable. Census 2011 found that only about 37–40% of slum households were in notified slums, i.e. roughly 60% were in non-notified (recognised or identified) settlements.
• State laws: Maharashtra Slum Areas (Improvement, Clearance and Redevelopment) Act, 1971 — the basis of the Slum Rehabilitation Authority (SRA); Odisha Land Rights to Slum Dwellers Act, 2017 (JAGA Mission) which issues heritable and mortgageable but non-transferable land rights certificates to slum households in municipalities and notified area councils (the municipal corporations were initially outside its scope); Tamil Nadu Slum Areas Act, 1971, administered now by the Tamil Nadu Urban Habitat Development Board (the renamed Slum Clearance Board).
• Characteristics planners record: tenability (tenable / semi-tenable / untenable — on hazardous land, river banks, under HT lines, on alignments), density, structure type, service levels, tenure, livelihood dependence on location, and the cut-off date governing eligibility (varies by state and has been extended repeatedly — check the current notification).

Approaches to slum intervention

• Clearance and eviction (1950s–60s): demolition with little or no rehabilitation. Discredited — it destroyed housing stock and livelihoods without reducing slum formation.
• Relocation / resettlement: households moved to new sites, usually peripheral. Cheapest in land terms but causes livelihood loss, long commutes, school dropout and high resale/abandonment. Where land is acquired, R&R entitlements under the LARR Act, 2013 apply.
• In-situ upgrading (incremental improvement): keep the settlement, improve roads, water, drains, toilets, electricity, street lighting and solid-waste collection, plus home-improvement loans. Origin of the Environmental Improvement of Urban Slums (EIUS) programme, 1972. Cheapest per household, least disruption, but does not change tenure or structural quality unless tenure follows.
• Sites and services: serviced plots with a core unit (toilet + one room) allotted to households who build incrementally — Madras Urban Development Projects and other World Bank-aided projects of the 1970s–80s. Low capital cost per household; failure mode is downward raiding by higher-income buyers and peripheral location.
• Slum networking: treat the slum as part of the city's trunk networks, using natural drainage lines — Indore Habitat Improvement Project (Himanshu Parikh); low-cost sewerage along the lowest contour.
• In-situ redevelopment (ISSR): demolish and rebuild multi-storeyed tenements on the same land, financed by cross-subsidy from a free-sale component built with incentive FSI, land as a resource. Highest quality uplift; risks are very high densities, transit camps, long gestation, maintenance costs that poor households cannot pay, and exclusion of ineligible households.
• Community-led / assisted self-help: savings groups, community contracting and enumeration by federations such as NSDF/Mahila Milan with SPARC; community toilets built and maintained by residents.
• Tenure instruments: freehold patta, long leasehold, collective/community tenure, conditional tenure (non-transferable for a lock-in period), and "no-eviction guarantee" — a graded ladder; security of tenure is what triggers household investment in the house.

Indian programmes and policy, in sequence

• EIUS (1972), Urban Basic Services (1980s), Nehru Rozgar Yojana shelter upgradation, NSDP (National Slum Development Programme, 1996), VAMBAY (2001) — Valmiki Ambedkar Awas Yojana, dwelling units plus Nirmal Bharat Abhiyan toilets.
• National Urban Housing and Habitat Policy, 2007: "affordable housing for all", land as a resource, 10–15% of land or 20–25% of FAR in new projects for EWS/LIG, in-situ upgradation preferred.
• JNNURM (2005–14): BSUP (Basic Services to the Urban Poor) for 65 mission cities and IHSDP for other towns — housing plus water, sanitation, roads and community facilities, with a 7-point charter and 10–12% beneficiary contribution.
• Rajiv Awas Yojana (RAY, 2011–13/14): the "slum-free India" framework — total station/GIS slum survey and mapping, socio-economic and biometric household survey, MIS, and a Slum-Free City Plan of Action (SFCPoA) with curative (upgrade existing slums) and preventive (supply of affordable housing and reserved land) components; also required a state law assigning property rights.
• PMAY-Urban 1.0 (June 2015, extended to 31 December 2024 for completion of sanctioned houses) — four verticals:
  1. ISSR — In-situ Slum Redevelopment using land as a resource, central assistance ₹1 lakh per rehabilitated slum dwelling, flexible for the state/ULB to use anywhere in the project.
  2. AHP — Affordable Housing in Partnership, central assistance ₹1.5 lakh per EWS unit in a project where at least 35% of houses are EWS.
  3. BLC — Beneficiary-Led Construction/enhancement on the beneficiary's own land, ₹1.5 lakh per unit.
  4. CLSS — Credit Linked Subsidy Scheme, net present value of interest subsidy credited upfront: 6.5% for EWS/LIG on ₹6 lakh of loan for 20 years (about ₹2.67 lakh), 4% for MIG-I on ₹9 lakh and 3% for MIG-II on ₹12 lakh (about ₹2.35 lakh and ₹2.30 lakh); CLSS for MIG closed earlier than the EWS/LIG window.
  5. Mandatory conditions: house in the name of the female head or joint name (EWS/LIG under BLC/AHP), toilet, and geo-tagged progress on the MIS.
• PMAY-U 2.0 (approved 2024, for 2024-25 to 2028-29): 1 crore houses, with verticals BLC, AHP, ARH (Affordable Rental Housing) and ISS (Interest Subsidy Scheme) — the ISSR vertical of 1.0 was not carried forward in the same form, and per-unit assistance was enhanced; quote the current operational guidelines for exact amounts.
• ARHC (2020): Affordable Rental Housing Complexes for urban migrants/poor — Model 1, converting existing vacant government-funded housing through concession agreements; Model 2, construction and operation by public/private entities on their own land with incentives. Model Tenancy Act, 2021 (a model for states to adopt) regularises written tenancies, security deposits (two months for residential) and rent authorities.
• Related: DAY-NULM for livelihoods and shelters for the urban homeless; PM SVANidhi for street vendors; Street Vendors (Protection of Livelihood and Regulation of Street Vending) Act, 2014, which protects the livelihood side of the same households; RERA, 2016 for registration and carpet-area disclosure.

Planning and design standards for low-income housing

• NBC 2016 Part 3 (development control rules and general building requirements) governs plot sizes, set-backs, room sizes, light and ventilation, and includes relaxations for low-income housing; Part 4 fire and life safety matters for the tall rehabilitation towers that redevelopment produces.
• Indicative room standards: a habitable room of about 9.5 m² with a minimum width of 2.4 m (second room smaller), kitchen about 5.0 m², bath 1.8 m², WC 1.1 m², combined bath-WC 2.8 m², clear ceiling height generally 2.75 m. Low-income/one-room tenements get specified relaxations — always read the version of NBC and the local building bye-laws actually in force.
• URDPFI Guidelines, 2014 (MoHUA) give land-use and density norms, social-infrastructure thresholds (anganwadi, primary school, health post, community hall per population) and recommend reservation of land for EWS/LIG in all new development; residential density ranges are indicative and city-size dependent.
• Inclusionary housing: reservation of a share of FAR, dwelling units or layout area for EWS/LIG in group-housing and layout approvals — the share and the trigger threshold are state-specific (e.g. Maharashtra's inclusive-housing condition for larger layouts, Haryana's affordable-housing policy, Delhi's MPD provisions). Compliance is often satisfied by cash or off-site units, which weakens the intent.
• Mumbai's SRA model — DCPR 2034 Regulation 33(10): eligible hutment dwellers (as per the notified cut-off) get a free self-contained tenement of 300 ft² carpet (raised from 269 ft²); the scheme needs the consent of a stipulated majority of eligible slum dwellers (historically 70%, since relaxed to 51% for certain schemes — confirm the current provision); the developer gets incentive FSI linked to the rehabilitation area, with permissible FSI on the plot up to 4.0 and the balance taken as slum TDR usable elsewhere; a corpus fund is deposited for maintenance. Variants: 33(11) for transit camps, 33(14) for PPP redevelopment, and the Dharavi Redevelopment Project, a separately notified scheme under implementation.
• Delhi: DUSIB manages JJ clusters; the 2015 rehabilitation and relocation policy follows the "jahan jhuggi wahan makan" principle with in-situ rehabilitation where land is tenable, and 25 m²-class flats where relocation is unavoidable; cut-off dates for cluster and dweller eligibility are policy-fixed and have been litigated and revised.

Finance, delivery and why schemes fail

• Sources: central assistance, state share, ULB share, beneficiary contribution, housing loans (HFCs, banks, priority-sector), land value capture (incentive FSI, TDR, land monetisation), CSR and the National Urban Housing Fund; CRGFTLIH credit guarantee for small housing loans to the informal sector.
• Technology: six Global Housing Technology Challenge (GHTC-India) technologies — precast sandwich panels, monolithic shuttering, light-gauge steel framing, prefabricated steel structures, etc. — with Light House Projects built in six cities as demonstrations.
• Common failure modes: peripheral land; eligibility cut-offs excluding tenants, newer migrants and the structure-less; 25 m² one-room units unsuitable for home-based work; lift, pump and common-area maintenance costs of ₹500–1,500/month beyond household capacity; vertical slums with poor light and ventilation; unsold free-sale stock stalling the rehabilitation component; and informal resale or renting out of allotted flats.
• What good practice requires: in-situ wherever tenable, a transparent survey with grievance redress, tenure security, livelihood protection, incremental and expandable design, community participation in design and in operation and maintenance, and a preventive supply of serviced land so new slums do not form.

Key points

• Census slum categories - notified, recognised and identified; eligibility and funding historically follow notification.
• Census 2011 slums - 1.37 crore households, 65.5 million persons, 17.4% of urban population, reported in 2,613 towns.
• TG-12 shortage - about 1.88 crore urban dwelling units in 2012, over 95% in EWS and LIG; alongside about 1.1 crore vacant urban houses.
• Housing shortage formula - new households + congestion + obsolescence + vacancy reserve + homeless.
• Tenability - tenable, semi-tenable, untenable; only untenable sites justify relocation.
• In-situ upgrading - cheapest per household, no displacement, but no change in tenure or structure unless added.
• Sites and services - serviced plot plus core unit, built incrementally by the household.
• ISSR - in-situ redevelopment using land as a resource, cross-subsidised by a free-sale component on incentive FSI.
• PMAY-U 1.0 verticals - ISSR (₹1 lakh/DU), AHP (₹1.5 lakh/EWS DU, min 35% EWS), BLC (₹1.5 lakh), CLSS (interest subsidy, NPV upfront).
• PMAY-U 2.0 - BLC, AHP, ARH and ISS; 1 crore houses over 2024-25 to 2028-29.
• RAY - GIS slum mapping, biometric survey, MIS and a Slum-Free City Plan of Action with curative and preventive parts.
• Reg. 33(10), DCPR 2034 - 300 ft² carpet free tenement, incentive FSI, permissible FSI up to 4.0, balance as slum TDR, maintenance corpus.
• Slum TDR - development rights generated in a slum scheme and consumed on another plot, subject to zone and FSI caps.
• LARR Act, 2013 - rehabilitation and resettlement entitlements where land is acquired for the project.
• Affordability rule of thumb - housing payment of 30-40% of monthly household income; land price, not construction cost, is what breaks affordability.
• Cross-subsidy - the market/free-sale component funds the EWS component; it fails when the free-sale market is weak.
• Standards - NBC 2016 Parts 3 and 4 for building requirements and fire safety; URDPFI 2014 for densities and social infrastructure; local bye-laws prevail.
• Prevention - without a continuous supply of serviced, well-located land for EWS/LIG, redevelopment only recycles existing slums.

Formulas and examples

Example 1 — Housing requirement and shortage for a town (15-year plan). Present population 2,40,000; projected 2041 population 3,60,000; h = 4.5; existing acceptable stock 50,000 DU of which 3,000 are dilapidated beyond repair; vacancy reserve 3%.

• Present households = 2,40,000 / 4.5 = 53,333; 2041 households = 3,60,000 / 4.5 = 80,000.
• Net new households = 80,000 − 53,333 = 26,667.
• Congestion backlog = 53,333 − 50,000 = 3,333 (households sharing dwellings).
• Obsolescence replacement = 3,000; vacancy reserve = 3% × 80,000 = 2,400.
• Total requirement = 26,667 + 3,333 + 3,000 + 2,400 = 35,400 DU, i.e. 2,360 DU per year.
• If 60% must be EWS/LIG: 21,240 units — the figure that drives the land reservation in the development plan.

Example 2 — In-situ slum redevelopment feasibility (Mumbai-type Reg. 33(10) arithmetic). Slum plot 2.0 ha (20,000 m² = 2,15,278 ft²), 1,000 eligible hutments, 300 ft² carpet each, common-area factor 0.20, incentive ratio 1.0, permissible FSI 4.0.

• Rehab BUA = 1,000 × 300 × 1.20 = 3,60,000 ft².
• Sale BUA = 3,60,000 × 1.0 = 3,60,000 ft²; total = 7,20,000 ft².
• Maximum in-situ BUA = 2,15,278 × 4.0 = 8,61,112 ft² > 7,20,000 ft², so the whole scheme fits on site and no slum TDR is generated.
• Rehab density check: 1,000 DU on 2.0 ha = 500 DU/ha; at 4.5 persons/DU = 2,250 persons/ha — very high, so open space, light, ventilation, parking and fire-tender access under NBC 2016 Part 4 must be verified explicitly.
• If the incentive ratio were 1.5, total BUA = 3,60,000 + 5,40,000 = 9,00,000 ft², exceeding 8,61,112 ft² by 38,888 ft², which would have to be taken as slum TDR elsewhere.

Example 3 — Affordability and the subsidy gap. LIG household income ₹18,000/month; 35% available for housing; loan at 8.5% for 20 years; own savings ₹80,000; capital assistance ₹2.5 lakh.

• EMI capacity = 0.35 × 18,000 = ₹6,300/month. i = 0.085/12 = 0.0070833, n = 240, (1+i)²⁴⁰ ≈ 5.442.
• EMI factor = 0.0070833 × 5.442 / (5.442 − 1) = 0.038556 / 4.442 = 0.008680.
• Loan supportable = 6,300 / 0.008680 ≈ ₹7.26 lakh.
• Affordable house price ≈ 7.26 + 0.80 + 2.50 = ₹10.56 lakh.
• A 36 m² built-up unit at ₹22,000/m² construction = ₹7.92 lakh, leaving only ₹2.64 lakh for land, infrastructure, approvals and developer margin — about ₹7,330/m² of BUA. This is the whole reason affordable housing works only on cheap, publicly held or cross-subsidised land.

Example 4 — Cross-subsidy in an AHP project. 1,000 units: 600 EWS of 30 m² carpet (36 m² BUA) and 400 market units of 60 m² carpet (72 m² BUA). Construction ₹22,000/m² BUA; land plus infrastructure ₹60 crore; EWS sale price ₹7 lakh; assistance ₹2.5 lakh per EWS unit.

• EWS BUA = 600 × 36 = 21,600 m² → cost = ₹47.52 crore. Market BUA = 400 × 72 = 28,800 m² → cost = ₹63.36 crore.
• Total project cost = 47.52 + 63.36 + 60.00 = ₹170.88 crore.
• EWS recovery = 600 × (7.0 + 2.5) lakh = ₹57.00 crore.
• To be recovered from market units = 170.88 − 57.00 = ₹113.88 crore → ₹28.47 lakh per unit = ₹39,542/m² BUA. Feasible only if the local market rate exceeds this; otherwise the EWS share, the land cost or the FAR must change.

Where it is used

• Development authorities and ULBs: preparing housing chapters of master plans, EWS land reservation, slum-free city plans, DU budgets and layout approvals (DDA, MMRDA, CIDCO, BDA, HUDA).
• Slum and housing boards: SRA Mumbai, DUSIB Delhi, Tamil Nadu Urban Habitat Development Board, Odisha's JAGA Mission, state housing boards — survey, eligibility, allotment and scheme sanction.
• Planning and PMC consultancies: DPRs for AHP/BLC/ISSR projects, feasibility and incentive-FSI/TDR calculations, GIS slum mapping and socio-economic surveys.
• Private developers and contractors: SRA and cluster-redevelopment schemes, Reg. 33(10)/33(14) projects, the Dharavi Redevelopment Project, GHTC technologies and Light House Projects.
• Housing finance and guarantee institutions: NHB, HUDCO, HFCs and banks appraising EWS/LIG loans, CLSS/ISS subsidy processing, informal-income underwriting.
• NGOs, CBOs and research: SPARC/NSDF/Mahila Milan, Hunnarshala, community toilets and sanitation, plus the planning job roles of housing analyst, GIS analyst and monitoring-and-evaluation officer on mission MIS data.

Interview questions

• Q: What are the three Census categories of slums and why does the difference matter? A: Notified, recognised and identified. Notification determines legal protection, eligibility for schemes and compensation, so non-notified settlements — roughly 60% of slum households in 2011, since only about 37–40% were in notified slums — are the most vulnerable.
• Q: What does "land as a resource" mean in slum redevelopment? A: The scheme is funded by monetising the development potential of the slum land itself — the developer builds free rehabilitation tenements and recovers cost from a free-sale component built on incentive FSI or from TDR, instead of a cash subsidy.
• Q: When is relocation justified rather than in-situ redevelopment? A: Only when the site is untenable — hazardous, on a right of way, under HT lines, on a water body or in a flood/landslide zone — because relocation imposes livelihood, commuting and schooling losses.
• Q: How is urban housing shortage computed? A: Net new household formation plus congestion (households sharing or overcrowded), plus replacement of obsolete stock, plus a vacancy reserve and homeless households; the TG-12 estimate for 2012 was about 1.88 crore, over 95% EWS/LIG.
• Q: What are the four verticals of PMAY-U 1.0 and the assistance under each? A: ISSR at ₹1 lakh per slum dwelling, AHP at ₹1.5 lakh per EWS unit in projects with at least 35% EWS, BLC at ₹1.5 lakh, and CLSS interest subsidy of 6.5% on ₹6 lakh for EWS/LIG and 4%/3% for MIG-I/MIG-II.
• Q: What is slum TDR? A: Development rights generated when a slum scheme's total entitlement exceeds what the plot's permissible FSI can hold in-situ; the balance is certified and consumed on another plot, subject to receiving-zone and FSI limits.
• Q: Why do rehabilitated families sometimes sell or abandon their flats? A: Monthly maintenance, lift and pump charges and property tax exceed what the household can pay, the unit cannot house home-based work, and the location or the unit size does not suit the family — so they rent or sell and move back to informal housing.
• Q: Why is tenure security the key to slum improvement even without new construction? A: Households invest in their own house incrementally once eviction risk falls; a heritable certificate, as under Odisha's 2017 Act, unlocks that investment and makes service provision legally possible.
• Q: Difference between gross and net residential density? A: Net density counts only the residential plot area; gross density includes internal roads, parks and local facilities, so gross density is always lower — quoting one for the other is a classic error.
• Q: What is the difference between carpet, built-up and super built-up area? A: Carpet area under RERA is net usable floor area excluding external walls, balconies and shafts but including internal partition walls; built-up adds wall thickness and balcony; super built-up adds a share of common areas. PMAY carpet-area caps are on carpet area only.
• Q: How does an inclusionary housing provision work and why does it under-deliver? A: A share of FAR, units or layout area in private projects is reserved for EWS/LIG; it under-delivers because developers often discharge the obligation in cash or with off-site, poorly located units.
• Q: What did RAY add that earlier slum programmes lacked? A: A city-wide, survey-based plan — GIS slum mapping, biometric household survey, MIS and a Slum-Free City Plan of Action with both curative and preventive components, plus a state law assigning property rights.

Common mistakes

• Quoting housing shortage as only the gap between households and houses, omitting congestion, obsolescence and the vacancy reserve.
• Confusing gross and net residential density, or quoting DU/ha where persons/ha was asked (they differ by the household size).
• Applying PMAY carpet-area limits to built-up or super built-up area, and mixing ft² with m² inside one calculation.
• Treating all slums as illegal encroachments on public land — many are on private land, on tenanted chawls, or are notified and legally protected.
• Assuming eviction can precede rehabilitation; and ignoring the state cut-off date and consent requirement that make or break an SRA-type scheme.
• Writing "slum clearance" as current policy — in-situ upgrading or redevelopment is the policy default, with relocation reserved for untenable land.
• Costing only construction and forgetting land, trunk infrastructure, approvals, transit accommodation and the maintenance corpus — the items that actually decide feasibility.

Related topics

Master plans and development plans · Land use planning and zoning regulations · Urban design and planning · Building planning and bye-laws · Urban infrastructure planning: water, sanitation and drainage · Urban land economics and land value capture