Last month, i just moved in to exactly same land size, double storey house after renovation for about 6mths (delay here and there).
Scope of renovation is about the same with yours. I spent slightly more than RM150k on that and yet still bare unit with no cabinet for living room and rooms. Just kitchen with aluminium cabinets.

Priorities
1. Wiring Works, full makeover. (Planning to change to 3-phase current too or is it unnecessary?)
check the conditions of the wire first but full make over is actually costly. Additional points might save provided existing wires in good condition.

2. Piping and plumbing Works, full makeover if necessary.
better to perform full makeover since you are also changing the spare tank to a bigger 1. Use better pipe materials such as HDPE or PPR.

3. Removal of an old solar water heater by previous owner.
if the condition is still ok, you may check whether can trade-in or not. Might save you abit

4. Total makeover of three bathrooms
i would suggest to demolish all 3 bathrooms and install with new water routes, tiles, waterproofing and new sanitary setup. Plan nicely to achieve best result.

5. Installation of >1500L water tank and water heater. (Pump too if necessary)
check the location whether allow you to install a bigger tank or not. Remember to add a switch for pump on/off.

6. Demolishing a "Partition Wall" extended front section of the house and new door.
double check the developer drawing (if available) to avoid structure damage.

7. Replacing badly damaged parquet floor on 2nd floor with tiles.

8. Replacing four segments of damaged windows.
you may consider security windows if budget allows

9. Replacing damaged backdoor
you may consider security door if budget allows

Other wants
1. Adding a better water filter system.
water quality is very important. Get a good 1, or you may add during later stage.

2. Redo the existing tiles on the kitchen counter top spanning about 8 meters.
get a good quality tiles, you can opt for 60mmx120mm

3. Replacing kitchen cabinet to something more durable, perhaps aluminum cabinets?
aluminium is very much expensive, you may opt for wood for wall units

4. Replacing the 11' gate with a 15' auto gate (trackless or non trackless?)
I assume you are looking for folding gate, definitely trackless. Consider 16' to 18' if allows. Folding arm need 1' clearance for each pillar.

5. Adding alarm system (smoke alarm too).
As this might involve wires laying, better to consult specialist during early stage.

6. Replacing room door knobs
can consider DIY, many tutorials

7. Hacking a 7' wide wall to add a walk-in wardrobe segment. whistling.gif


Additional suggestions:
1) Hood / Hob
2) Kitchen sink and faucet
3) Fans, lightings, switches
4) Plaster ceiling (if any)
5) Painting (outdoor, indoor, grills, maybe roof)
6) doors for bathroom
7) curtain or blind

This post has been edited by CanonLee: Feb 24 2021, 02:40 PM

wet work, demolitions, construction, wiring, pipings are top priorities.
Replacement of bad condition fixtures would be next
Following by additional fixtures, accessories, furnitures and etc.

are u engaging ID for whole renovation or just for ideas? The extension of living hall is not really big portion since you are thinking about full make-over of wirings.
i changed my main door to 6' steel safety door (very common, TPC/NEW EDGE/RHINO and etc). DELUX safety door is made from aluminium and definitely more expensive.
I dont suggest to put tank at porch because it eats up space and also not nice to see.
For kitchen countertop, ask for more opinions first.
your kitchen cabinet's doors seems ok-ish condition. Might just need to re-paint the door and change the hinges. Remove the door before hacking of existing countertop tiles. the carcass probably unable to restore. Anyway the length is so long!

for the folding gate, as the gate is folded once you open the gate, so it will it up about 1ft. Say if your gate is 15' then the clearance will be slightly more than 13'.