Rainwater harvesting is not an amenity. It is a condition of the permission

Brochures for large projects tend to list rainwater harvesting, solar water heating and organic waste composting alongside the clubhouse and the jogging track. Three of those four are compulsory above a stated size, and one of them is a condition of the permission the project was granted.

Rainwater harvesting, and the sentence that gives it teeth#

Chapter 13, Regulation 13.3, UDCPR as updated 30 January 2025 applies to all layout open spaces and amenity spaces of housing societies, and to new construction, reconstruction or additions on plots of not less than 500 sq m. Each must have one or more rainwater harvesting structures with a minimum total capacity set out in the Schedule to the regulation, though the Authority may approve different specifications provided the minimum capacity is met.

Then two clauses that turn a design requirement into a continuing obligation.

The owner or society must keep it working. The regulation requires them to ensure the system is maintained in good condition, for storage of water for non-potable purposes or for recharge of groundwater, at all times.

And the consequence is not only a fine. The Authority may impose a levy of up to Rs.1000 per annum for every 100 sq m of built up area for failure to provide or maintain the structures. Then the sentence that matters most: failure to provide a rainwater harvesting system shall be deemed to be a breach of the conditions on which the development permission has been granted.

Solar, and the quarter of the roof#

Chapter 13, Regulation 13.2, UDCPR as updated 30 January 2025 makes solar assisted water heating or a rooftop photovoltaic system mandatory in all types of buildings to be constructed on a plot area of more than 4,000 sq m.

To make that workable, the regulation imposes design requirements on the building itself.

The 25 percent figure is the one to hold on to. A quarter of the terrace on a qualifying building is committed to this by regulation, which is a useful thing to know when a society later debates covering the roof with something else, and when a developer describes the terrace as available common space.

Waste, and the 100 percent standard#

Chapter 13, Regulation 13.5, UDCPR as updated 30 January 2025 is mandatory for housing complexes, commercial establishments, hostels and hospitals with an aggregate built up area of more than 4,000 sq m, and for all three star or higher category hotels.

Those buildings must establish a dedicated solid waste management system to treat 100 percent of the wet waste generated in them. Treatment is through organic waste composters, vermiculture pits or similar technologies of suitable capacity, installed through reputed vendors. Dry waste, e-waste and hazardous waste go through authorised recyclers or another system the Authority specifies.

Note the threshold here is built up area, not plot area, so it catches a tall building on a small plot that the solar and rainwater thresholds might not.

Grey water, and what it may never be used for#

Chapter 13, Regulation 13.4, UDCPR as updated 30 January 2025 defines grey water as waste water from bathrooms, sinks, showers and wash areas, and applies to developments and redevelopments in the categories it lists.

For residential layouts of 10,000 sq m or more, a separate space for a grey water treatment and recycling plant must be proposed in the layout, in addition to the 10 percent open space, and it may be located in the amenity space under Regulation 3.5. Drainage lines, chambers and plumbing lines must be marked in different colours on the layout submitted for approval.

The applicant must submit, with the application, a plan showing the location of the plant with calculations and implementation details, together with a commitment to monitor the system periodically from the date of occupation.

How much of the register each rule reaches#

83.9 percent of published projects sit on 500 sq m or more, so the rainwater obligation is close to universal in the register. Solar reaches 22.8 percent and grey water recycling 8.7 percent, which is what you would expect from thresholds set at 4,000 and 10,000 sq m.

What to ask#

1. Ask where the rainwater harvesting structures are on any plot of 500 sq m or more, and who maintains them.
2. On a plot above 4,000 sq m, ask what share of the terrace the solar system occupies, since the regulation commits at least a quarter.
3. Ask what happens to wet waste on site, because above 4,000 sq m of built up area the answer must be a system treating all of it.
4. On a large layout, ask to see the colour coded plumbing plan, which is required at approval where grey water recycling applies.
5. Treat these as compliance, not as amenities, when comparing two projects on price.

Where the filings come in#

The register does not record whether a rainwater pit was dug. What it does record, free, is the project's filed land area, which is what decides whether most of these obligations apply at all, along with the buildings and their floors, the promoter's extension history with the stated reasons, the certifying professionals, and any complaints or litigation with case numbers.

That is enough to work out which of these rules your project is inside, before you ask anyone a question. Every MahaRERA filing is readable at reragenie.com without an account.

ReraGenie's buyer report, Rs 499, reads one project's full filing and the documents behind it, sets the promoter's record against the rest of the register, compares the possession slip with the median for the same pincode, and lists what the filings do not contain. It includes a project watch for 90 days.

For the newest mandatory provision of this kind, a 25 sq m ladies room required free of FSI in non-residential buildings, see the two floors the code gives away.

Source: Unified Development Control and Promotion Regulations for Maharashtra, UDCPR as updated 30 January 2025. Sanctioned under the Maharashtra Regional and Town Planning Act, 1966.