Hi guys,
I’m planning to build an attic / loteng in my middle room’s house.

Middle room orientations:
EAST - facing living room
WEST - facing my neighbour’s
NORTH - facing kitchen
SOUTH - facing entrance to my master bed room

My house is a semiD 1 storey somewhere in Kedah.

The room size is as follows (all dimensions are in feet):

Length: 12.5
Width: 10
Height: 20

Main reason is that, middle room is very high, having 20ft as opposed to other rooms (11ft height floor to ceiling).
Thus, i would want to utilize the space by splitting the room into GF (ground floor) & 1F (first floor).

My questions are as follow:

1. I’m trying to think a suitable design on how to VENTILATE the GF room. I’m thinking to ask the contractor to make a small rectangular hole & put a ventilation window (like the typical toilet ventilation window) to give room more ventilation (apart from having a 1HP inverter AC inside there).

So my question: what is the suitable size for the rectangular ventilation window size?
Or should i install an EXHAUST FAN? But that would look UGLY and will be NOISY ya?

FYI, the ventilation window will face the LIVING ROOM area in my house (facing EAST; refer to image below).

2. I want to install AC at the GF room. So in order to DRAIN OUT the condensation water, i had to resort to use a DRAIN PUMP together with the AC, where the pump will bring the water UPWARDS and towards the existing window at 1F.

AC at 1F can just direct the water thru the existing window there via gravity.
(2 ACs; one at GF & one at 1F)

So my question: which AC DRAIN PUMP model is good? Height from the GF AC to the window at 1F will be around ~4 feet.

3. Contractor quoted me nearly RM10k for this attic project.
Is this a reasonable price?

Anybody got do attic project before?
Pls do share how you guys do it.

Appreciate your feedbacks guys.