Please check your SPA, there is always a term that related to defects. In standard practice, upon received the defect list from you, developer have 45 days to rectify the defects. In the event the defects is not rectify after 45 days,

1) purchaser need to obtain a quotation from third party;
2) issue a letter to developer where your intended to rectify the defects yourself by enclose the quotation;
3) if no feedback from the developer with the specific period, you can proceed with the work and claim back from the developer.

Please provide more details.
Landed, strata development, or subdivide land or ???

if the plan is approved, normally PTG may take few months to issue the new title.

Schedule H for high rise building,

Schedule G for landed property

Go back to the developer or consultant team if possible. or if high rise, may be MO office.

They may have many factors why they c't obtain the strata title.
Commond problem for old project before SMA 2013: -

1) Do not have SIFUC / Schedule of Parcel approval;
2) Delay in government agencies like COB, Surveyor Department, Land Department (very common)
3) Delay by their surveyor to carry out the final as-built measurement

Problem to owner may have some difficulties to borrow money, to sell the property and so on.

Potentially u may need to search from Uniform Building by Law (UBBL) or local authority design guidelines.

You may consider installing a standard exhaust fan as people install it in the kitchen.