Need help planning an electrical renovation
Your planning is a bit...off
Thailand, like most places in the world that aren't in North America, uses IEC style nomenclature and wiring, from what I can tell (the actual standards aren't available in English, but the two threads I found on the topic on a Thai expat forum are thoroughly steeped in IEC terminology, such as RCD/RCBO, metric wire sizing, 400Y/230 LV distribution everywhere, and so on).  As a result, 15A isn't even considered a standard breaker size, and Thai wiring rules apparently limit 1.5mm² to 10A anyway, with 16A circuits requiring 2.5mm² wire instead.
Given this, and the fact that Thailand, while having a legacy of using NEMA 1-15/5-15 plugs/receptacles (which is wrong, since those are a 120V config, not 220-240V), now uses its own plug standard (considered a &quot;Type O&quot; in the IEC taxonomy) rated for 16A/230V, you'll want to run your general appliance branch circuits as 16A circuits with 2.5mm² wire.  You may be able to use 10A circuits for lighting, though, so do check with someone locally knowledgeable about that.
Wet area receptacles (kitchen/bath/outside) as well as water-heater type appliances will need RCD protection, although it may or may not required panel-wide, best I can tell.  Eurostyle consumer units with DIN rail breakers may be permissible, although if you're going above about 24 breaker spaces, special IEC-rated versions of North American panelboard construction are available and may be preferable to the more traditional &quot;consumer unit&quot; construction.
Likewise, your service sizing will be...small by US standards.  It seems that 30/32A and 50A are common service sizes in Thailand, with larger services delivered as three-phase.  Speaking of large loads, note that that 2kW water heater will be perfectly happy on a 16A circuit, although the air conditioner may or may not require something larger.
Other than that, and any provisioning requirements the Thai standards provide, I'd provision:

two lighting circuits (so that one trip doesn't wipe out the whole house's lights)
a dedicated spur for the fridge
two kitchen receptacle circuits
a bathroom receptacle circuit
a circuit for washer + dryer
your water heater and AC circuits
and circuits for bedrooms and living spaces as Harper describes (basically, splitting each room across 2 receptacle circuits shared between adjacent rooms)

Last but not least, Thailand apparently uses TN-C-S grounding, similar to what we do over here in North America.