Building Materials for a House in Goa, Konkan and Mangaluru: What to Use and Why

On the coast from Goa through the Konkan to Mangaluru, build the walls in laterite (or ash brick, AAC or concrete block where the fly ash rule, budget or speed decides), put a steep roof of Mangalore-pattern clay tiles over them with deep eaves, and detail every piece of concrete for salt air. The reasons are three: 3,000 to 3,750 mm of rain that arrives almost all at once, sea air that attacks steel, and a local stone and a local tile that grew up answering both.

About the numbers below: Climate figures are IMD normals for 1991 to 2020. Material requirements come from the BIS standards named. Rates are indicative items from the Karnataka PWD Schedule of Rates 2023-24, excluding GST, read on 17 Oct 2026; they are not quotes and do not apply as-is in Goa or Maharashtra. The material picks are MOA's professional guidance, not a rule.

What the coast asks of a house

Rain: a whole year's worth in four months

India Meteorological Department climatological tables for 1991 to 2020 put the belt among the wettest places anyone builds houses in India:

Station	Rain in a year	Rainy days	Share falling June to September	Mean daily high / low
Ratnagiri	3,245 mm	96	94%	29 to 34 °C / 18 to 26 °C
Panaji	2,984 mm	97	91%	29 to 34 °C / 20 to 26 °C
Mangaluru	3,748 mm	116	86%	29 to 34 °C / 21 to 25 °C

July alone brings about 955 mm to Panaji, 1,042 mm to Ratnagiri and 1,096 mm to Mangaluru. From December to March there is almost none. So a house here spends four months under water pouring off the roof and eight months drying out, and every material choice below follows from that.

Climate zone, earthquakes and wind

The Bureau of Energy Efficiency's Eco-Niwas Samhita 2018 lists Panjim, Ratnagiri and Mangaluru as warm-humid, the zone where shade, cross-ventilation and a roof that keeps heat out matter most.

For earthquakes, IS 1893 (Part 1):2016 lists Panjim, Karwar and Mangaluru in Zone III, with a zone factor of 0.16. Ratnagiri is not in its town list, so your structural engineer should read its zone off the code's map. BIS issued a revised code with a new zone map in November 2025, but withdrew it by gazette notification in March 2026 and the 2016 code applies again, as ETV Bharat reported.

For wind, IS 875 (Part 3):1987 gives a basic wind speed of 39 m/s for both Panjim and Mangalore. That is a design figure for your engineer, but it is also the reason loose roof tiles are a coastal problem.

Salt air

Concrete near the sea is treated as a harsher case. IS 456:2000 classes concrete "exposed to coastal environment" as severe exposure. For reinforced concrete that means a minimum grade of M30, at least 320 kg of cement per cubic metre, a water-cement ratio of no more than 0.45 and a nominal cover of 45 mm to the steel. Surfaces hit by sea-water spray are very severe: M35 and 50 mm cover. The code also says sea water is not recommended for mixing or curing concrete because of its salts.

Materials card for the coast from Goa to Mangaluru. Three monthly rainfall charts from IMD normals for 1991 to 2020: Ratnagiri 3,245 mm a year with 94% falling June to September, Panaji 2,984 mm with 91%, and Mangaluru 3,748 mm with 86%, all with daily highs of 29 to 34 °C and a warm-humid climate. Below: laterite ground, seismic Zone III under IS 1893 (Part 1):2016, a basic wind speed of 39 m/s, and severe exposure for concrete in salt air under IS 456. Four recommendation cards: laterite or ash brick, AAC or block walls; a pitched Mangalore-tile roof; M30 concrete with 45 mm cover; and plaster with drips, deep eaves and a high plinth. — The coastal belt on one card: rain, heat, ground, quake, wind and salt, with the wall, roof, concrete and finish that answer them. Diagram: MOA

Walls: laterite, with company

Laterite is the walling stone of this coast. IS 3620:1979, the standard for laterite masonry blocks, names Goa, Karnataka and Maharashtra among the states where it occurs, and it is cut into blocks rather than fired. Buy it to that standard, let it season before use, and keep it under eaves; the rest of its technical detail belongs to your engineer and quarry.

The other walls are the ones you see across India: burnt clay brick, AAC blocks, solid and hollow concrete blocks, and ash bricks. On this coast there is one extra rule to know. The Environment Ministry's ash notification, as amended by S.O. 05(E) of 1 January 2024, requires all building construction projects within 300 km of a coal or lignite power plant, including "all private agencies", to use ash bricks, tiles or other ash-based products, provided they are offered at no more than the CPWD or state PWD schedule price. The Central Electricity Authority's fly ash report for 2021-22 lists coal stations in this belt, among them JSW Energy's 1,200 MW plant in Ratnagiri and Udupi Power Corporation's 1,200 MW plant at Udupi. The notification does not say whether it binds a family's own house, so ask your architect and local authority before you choose a wall.

Our guidance: whatever the block, judge it by its BIS mark or licence and a dated test certificate, not by a brand name. Walls facing the south-west monsoon need plaster or a deep verandah in front of them.

Roofs: why the Mangalore tile belongs here

Where the tile came from

The tile carries the city's name for a reason. Architect and researcher Priya Joseph, writing for Sahapedia from the Basel Mission's annual reports, records that the German Basel Mission set up its first tile workshop at Jeppu, Mangaluru, in 1863 under the missionary George Plebst, using clay from the banks of the Netravati. In 1865 it made about 360 tiles a day with two workers and a few bullocks; steam power replaced the bullocks in 1880, and the Jeppu unit rose to about a million tiles a year. It was the first of many factories in the region. The Basel Mission's own archive holds a photograph titled "Mangalore. Brother Plebst's tile-works", dated between December 1864 and February 1869, at Jeppoo. Over that time the region's curved potter's tile gave way to the flat, interlocking tile now sold under the Mangalore name.

What IS 654 asks for

The tile has its own Indian Standard, IS 654:1992, for machine-pressed interlocking clay tiles of the Mangalore pattern. It sets three sizes (410 × 235, 420 × 250 and 425 × 260 mm), which suit batten spacings of up to 320, 350 and 360 mm at full overlap, with a minimum overlap of 60 mm lengthwise and 25 mm widthwise. A dry tile should weigh 2 to 3 kg. Class AA tiles must carry an average breaking load of at least 1.0 kN (1.1 kN for the two larger sizes); Class A, at least 0.8 kN (0.9 kN). Each tile needs at least two batten lugs, two eave lugs and a tie-down hole near its lower end for a 1.6 mm wire, and must be marked with the maker's name or trade mark.

Diagram of Mangalore-pattern clay roof tiles under IS 654:1992. A schematic roof section shows overlapping tiles hooked over battens on a sloping rafter, labelled with batten spacing up to 320, 350 or 360 mm by tile size, overlap of at least 60 mm lengthwise and 25 mm widthwise, at least two batten lugs, and a tie-down hole at the foot of each tile for 1.6 mm wire. Tables list the three sizes, 410 by 235, 420 by 250 and 425 by 260 mm, a dry weight of 2 to 3 kg, and the two classes: Class AA with 18% maximum water absorption and 1.0 to 1.1 kN average breaking load, Class A with 20% and 0.8 to 0.9 kN. Site checks: the tile rings, lies flat within 6 mm, is free of grit over 2 mm and carries the maker's mark. — What the Indian Standard for Mangalore tiles asks for, and how to check a delivery before it goes on the roof. Diagram: MOA

Slab or frame, and fixings

Our guidance: with 39 m/s design winds and four months of driving rain, wire the tiles at the eaves, verges and ridge, keep the pitch steep enough to shed water fast, and bring the eaves well out past the walls. Tiles on reepers over a treated timber or steel frame are lighter and cheaper; tiles over a sloping RCC slab add a second line against leaks, and that slab is then coastal concrete under IS 456. Any steel frame near the sea needs a corrosion-resistant finish that is renewed.

Plaster, floors and finishes

Lime plaster is still an official schedule item. The Karnataka PWD Schedule of Rates keeps an item for two-coat lime plaster to IS 2394 in its chapter on conserving heritage structures, alongside ordinary cement plaster. Our guidance: on laterite, ask your architect whether a lime-based plaster or a cement plaster suits the wall and its exposure, and in either case fit drip grooves under sills and slabs so water falls clear.

For floors, the plinth matters more than the tile. Raise it above the worst water your site has seen, finish it with a damp-proof course, and slope the ground away from the house. Vitrified, terracotta and oxide floors all work once the slab below stays dry.

What these materials cost: an official schedule

Indicative schedule rates, not quotes. From the Karnataka PWD Schedule of Rates 2023-24, Volume 2 (Buildings), in force from 15 Nov 2023 and continued by a department order of 18 Apr 2024 from 1 April 2024 until further orders. Rates exclude GST.

Mangalore tiles, first class (basic material rate): ₹13 each
Mangalore tile roofing on a steel frame (frame extra): ₹294 per m²; ridge tiles ₹65 per m
Mangalore tile roofing with wood reepers over existing rafters: ₹806 per m² (Nandi wood reepers) or ₹673 per m² (jungle wood)
For comparison, precoated GI profile sheet roofing (purlins and trusses extra): ₹568 per m²
20 mm cement plaster, 1:4: ₹354 per m²
Lime plaster, two coats of 10 mm (heritage chapter): ₹999 per m²
Fly ash brick masonry (class 5), cement mortar 1:6, above plinth: ₹7,627 per m³
AAC block masonry, 150 to 300 mm, with adhesive mortar and RCC bands: ₹7,978 per m³

Volume 1 of the same schedule adds a 12% area loading for coastal areas up to 25 km from the coast and for areas with 1,600 mm or more of rain.

These figures apply to Karnataka public works. The Karnataka schedule itself says work in another state should use that state's schedule, and we could not open a current Goa PWD buildings schedule online, so for Goa and the Konkan, ask the Goa PWD or Maharashtra PWD division office for their current item rates and get written quotes from two or three local suppliers. For the whole-house budget, see our state-wise construction cost breakdown or MOA's home cost calculator.

Mistakes to avoid

Short eaves on a coastal house. The roof is the first wall against the monsoon.
Loose tiles. Unwired tiles lift in strong wind; IS 654 puts a tie-down hole in every tile for a reason.
Thin cover and weak concrete near the sea. Ask your engineer to design exposed RCC for severe exposure, and never let site staff use sea water.
Tiles or blocks with no maker's mark or test certificate. Tap a few tiles from each lot: a sound one rings.
Masonry and roofing in June and July. Plan the work for the dry months, as our house construction timeline explains.
Skipping the land checks. Coastal plots carry their own permissions; run the plot checks before you buy.

FAQ

What is the best material for house construction in Goa?

There is no single best. Laterite is the local stone and suits the climate if it is seasoned, tested and kept under deep eaves; ash brick, AAC and concrete block are sound alternatives, and the fly ash rule may require ash products near a coal plant. Pair any of them with a pitched tiled roof and concrete detailed for salt air.

Are Mangalore tiles still a good roof today?

Yes, for this coast. They shed heavy rain fast, and a broken tile can be swapped on its own. Buy tiles that meet IS 654, check the class and the maker's mark, and wire them down.

What is the Mangalore tile price?

The Karnataka PWD Schedule of Rates 2023-24 lists first-class Mangalore tiles at ₹13 each and tiled roofing on a steel frame at ₹294 per m², excluding GST and the 12% coastal loading. These are indicative; ask local suppliers for current quotes.

What concrete grade should I use for a house near the sea?

IS 456 treats a coastal environment as severe exposure: at least M30 with 45 mm cover for reinforced concrete, and M35 with 50 mm where sea spray reaches. Your structural engineer sets the final specification.

Building on the coast? An architect who knows the monsoon and the sea air can choose the right wall, roof and details for your plot. Find an architect on MOA, or start with our guide to architects in Goa.

Sources

India Meteorological Department: climatological tables 1991 to 2020 for Ratnagiri, Panaji (Goa) and Mangaluru (accessed 17 Oct 2026)
Bureau of Energy Efficiency: Eco-Niwas Samhita 2018, Annexure 2, climate zones for major Indian cities (accessed 17 Oct 2026)
Bureau of Indian Standards: IS 1893 (Part 1):2016, Criteria for earthquake resistant design of structures, Annex E, via Public.Resource.Org on the Internet Archive (accessed 17 Oct 2026)
ETV Bharat: A bold policy reversed, the withdrawal of India's 2025 seismic code (11 Mar 2026) (accessed 17 Oct 2026)
Bureau of Indian Standards, via Public.Resource.Org: IS 875 (Part 3):1987, Wind loads, IS 456:2000, Plain and reinforced concrete, IS 3620:1979, Laterite stone block for masonry and IS 654:1992, Clay roofing tiles, Mangalore pattern (accessed 17 Oct 2026)
Ministry of Environment, Forest and Climate Change: S.O. 05(E), amendment to the ash notification, 1 Jan 2024 (accessed 17 Oct 2026)
Central Electricity Authority: Report on fly ash generation at coal/lignite based thermal power stations and its utilization, 2021-22 (accessed 17 Oct 2026)
Sahapedia: Priya Joseph, The Basel Mission and its Terracotta Products in Karnataka (accessed 17 Oct 2026)
Basel Mission Archives (mission 21): Mangalore. Brother Plebst's tile-works, ref. C-30.54.015 (accessed 17 Oct 2026)
Karnataka Public Works Department: Common Schedule of Rates 2023-24 (Volume 1, area-specific loading; Volume 2, Buildings) and continuation order of 18 Apr 2024 (accessed 17 Oct 2026)