Can you hack walls in an HDB flat?

Hacking walls in an HDB flat: the rule

HDB says all demolition and hacking of walls, partial or complete, needs its prior written approval (HDB's important information on renovations). That covers taking out a whole wall and hacking away only part of one. The same page lists hacking structural members, such as reinforced concrete walls, columns, beams and slabs, among its examples of disallowed building works.

In practice, the walls in your flat fall into two groups. A structural wall in an HDB flat must stay as it is. A non-structural wall can be removed only after approval, and some types also need a Professional Engineer, as the next section explains.

You are responsible for the renovations in your flat and must make sure your contractor follows HDB's guidelines (HDB renovation rules). Owners must engage only contractors from HDB's Directory of Renovation Contractors (DRC). You may face prosecution for not engaging a DRC contractor or for breaking the Housing & Development (Renovation Control) Rules.

Non-structural walls and the Professional Engineer

If you want to remove a wall in an HDB flat that is not structural, first ask your contractor what it is made of. HDB's building works guidelines list demolishing non-load bearing reinforced concrete (RC) elements, such as partition walls, party walls, stiffeners, lintols or hangers, among the works that need a permit (HDB's building works guidelines). HDB adds that all demolition or alteration of walls can only be carried out after obtaining its approval.

HDB sets these conditions for the work (HDB building works):

• Existing RC structures must not be tampered with.
• A Professional Engineer (PE) for civil or structural works must supervise the demolition of non-load bearing RC elements.
• The PE must also ensure proper repair of the affected RC elements.
• Give the PE a copy of the approved plan and conditions.

HDB's permit page explains that some works need a Qualified Person (QP), a Professional Engineer, to certify or supervise them, and demolishing non-load bearing RC elements is one of its examples (HDB's renovation permit page). HDB tells you and your contractor if your application needs a QP.

Putting up a new wall

A new partition is treated differently from a wall you take away. HDB says erecting a 63mm hollow block, 80mm glass block or gypsum partition wall needs no permit, but the work must still follow HDB's conditions (HDB building works guidelines). For a 63mm hollow block or 80mm glass block wall, those conditions are:

• Only one layer may be erected.
• A reinforced concrete lintol supports the hollow block across any opening.
• The escape route should be direct, for example from the bedroom door to the main exit door, and should not pass through another room.

No permit does not mean no rules. HDB's permit page says works that need no permit must still follow HDB's guidelines, or they are unauthorised works (HDB permit application). Settle where any new wall and door will sit before work starts, and add the layout to your pre-renovation checklist.

Who applies, and the hours

You do not apply for the permit yourself. HDB asks you to engage a contractor listed in the Directory of Renovation Contractors for all renovations in your flat, and you authorise that contractor to submit an electronic renovation application on your behalf, with an acknowledgement form signed by you (HDB renovation permit application). Works that need a permit start only after it is granted. Our guide to the HDB renovation permit covers the process in more detail.

Demolishing walls is a restricted (noisy) work. HDB allows restricted works only from 9am to 5pm on weekdays (HDB renovation hours and rules). They are not allowed on Saturdays, Sundays, public holidays or the eves of New Year's Day, Chinese New Year, Deepavali, Hari Raya Puasa and Christmas Day. General renovations run from 9am to 6pm on weekdays and Saturdays, with none on Sundays and public holidays.

HDB also says renovation contractors cannot take more than 3 consecutive days to demolish walls or remove wall or floor finishes (HDB's important information on renovations). See HDB renovation hours for the full timetable.

Before you sign

A few checks before you agree to any wall work:

• Ask the contractor to confirm which walls are structural from your approved plans.
• Ask whether the Professional Engineer's supervision is included. Price depends on the job, so also ask whether the quote is an hourly rate or fixed price.
• Get the permit before any hacking starts.
• Tell your neighbours in advance. HDB asks you to give units within a radius of 2 units a written notice at least 5 days before renovations begin (HDB neighbour notice).
• For smaller jobs once the renovation is done, compare handymen, or use find the right service if you are not sure which trade you need.

Questions