PÉCLETBuilding Physics
PÉCLET / India Climate Atlas05 Zones

Building
performance in
Indian climates.

A detail that is correct in one Indian climate zone can be a defect in another. This atlas sets out what governs each zone, what resource each one offers, and the order in which decisions should be taken.

Fig. 07 — Climate constellation50 locations
Leh — ColdKargil — ColdSrinagar — ColdManali — ColdShimla — ColdGangtok — ColdDarjeeling — ColdAmritsar — CompositeChandigarh — CompositeDehradun — CompositeDelhi — CompositeJaipur — CompositeLucknow — CompositeKanpur — CompositeGwalior — CompositePrayagraj — CompositeVaranasi — CompositePatna — CompositeBhopal — CompositeIndore — CompositeRanchi — CompositeNagpur — CompositeRaipur — CompositeHyderabad — CompositeBikaner — Hot & DryJaisalmer — Hot & DryJodhpur — Hot & DryBhuj — Hot & DryDwarka — Hot & DryAhmedabad — Hot & DryRajkot — Hot & DryGuwahati — Warm & HumidAgartala — Warm & HumidKolkata — Warm & HumidBhubaneswar — Warm & HumidSurat — Warm & HumidMumbai — Warm & HumidVisakhapatnam — Warm & HumidPanaji — Warm & HumidChennai — Warm & HumidMangaluru — Warm & HumidMadurai — Warm & HumidKochi — Warm & HumidThiruvananthapuram — Warm & HumidKanyakumari — Warm & HumidPort Blair — Warm & HumidNashik — ModeratePune — ModerateBengaluru — ModerateCoimbatore — Moderate68.5°E95°E

Equirectangular projection · Zones per National Building Code of India · Coordinates approximate

ClassificationFits no single other category for more than six months of the year

Two opposite briefs, six months apart, delivered by one envelope.

Governed bySeasonal reversalResource availableGenuine shoulder seasons · usable winter sunNot availableA single correct answer

A composite climate carries a hot dry season, a warm humid monsoon and a real winter. The envelope that performs in May is working against itself in January, which is why so many buildings here are uncomfortable in both.

The productive move is to identify which decisions serve both seasons — shading that admits low winter sun and rejects high summer sun, mass that damps in either direction, ventilation that can be opened and closed — and to treat the rest as a deliberate trade rather than an oversight.

The shoulder seasons are the hidden opportunity. There are substantial hours each year when outdoor conditions are directly usable, and capturing them requires openings positioned for flow rather than openings that merely open.

Order of decisions

  1. 01Resolve shading per orientation, for both solstices
  2. 02Damp with mass; place the insulation line outboard of it
  3. 03Seal the fabric so ventilation becomes controllable
  4. 04Capture shoulder-season and night hours deliberately
  5. 05Check the monsoon can dry out of the assembly
  6. 06Size systems for the residual, season by season

Common failures

  • Optimising for summer and producing an unheatable winter
  • Insulation broken at every floor slab and called continuous
  • Ignoring the monsoon because the analysis stopped at temperature

Composite locations

AmritsarChandigarhDehradunDelhiJaipurLucknowKanpurGwaliorPrayagrajVaranasiPatnaBhopalIndoreRanchiNagpurRaipurHyderabad