A&A Guidelines for Singapore Landed Homes, What BCA Allows & Doesn’t Allow

A&A Guidelines for Singapore Landed Homes, What BCA Allows & Doesn’t Allow

If you're planning to upgrade an older landed house in Singapore, whether it’s a terrace in Opera Estate, a semi-D in Serangoon Gardens, or a bungalow in Upper Bukit Timah, you’ve probably wondered:

What exactly does BCA allow under A&A? And where is the line between A&A and a full rebuild?

This is a crucial question because doing the wrong kind of works can trigger:

• stop-work orders

• costly redesign

• reclassification into a “rebuild”

• delays in approval

• additional structural requirements

This guide explains A&A rules in plain English, with real examples across Singapore’s landed neighbourhoods, and practical implications for homeowners.

1. What Is Considered A&A (Addition & Alteration)?

A&A includes works that modify, improve, or extend an existing house without demolishing the main structural framework.

A&A Examples:

• Rear extension (small to moderate)

• Enlarging kitchen or dining area

• Adding a bathroom

• Changing internal walls

• Installing skylights

• Adding mezzanine level (within structural limits)

• Partial roof upgrades or reconfiguration

• Façade modernisation

• Upgrading M&E (mechanical & electrical systems)

• Enlarging window openings

• Improving ventilation and natural light

A&A is suitable for older houses with strong bones, such as those in:

• Serangoon Gardens

• Thomson Ridge

• Binjai Park

• Seletar Hills

• Sunset Way

• Kew Drive / Bedok South

2. What A&A DOES NOT Allow

This is the part homeowners often misunderstand, and the part where BCA approval is strict.

Here’s what is NOT allowed under A&A:

1. You Cannot Demolish the Primary Structural Framework

This includes:

• main beams

• main columns

• majority of the roof structure

• primary floor slabs

If too many structural components are removed, BCA automatically classifies the project as a rebuild.

Example:

Older terraces in Frankel Estate where the owner wants to:

• remove front slab

• remove rear slab

• change entire staircase

• shift main beams

→ This exceeds A&A and becomes a rebuild.

2. You Cannot Add Full Additional Storeys

A 2-storey house CANNOT become a 3-storey house under A&A.

However, it may be possible to add:

• an attic (within envelope control)

• a mezzanine (if within structural load limits)

Terraces in:

• Telok Kurau

• Opera Estate

• Jalan Daud
  often add attic floors, but it must comply with URA’s envelope control rules.

3. You Cannot Change the Entire Building Envelope

Major roof redesigns or full elevation changes may trigger “rebuild” classification.

Small adjustments are allowed.
Full profile redesign = not allowed.

4. You Cannot Remove Staircases Without Structural Approval

Staircase removal affects structural load distribution.

Older semi-Ds in Serangoon Gardens or Sunset Way often have staircases in awkward spots.
Shifting them → A&A is possible ONLY if beams remain untouched.

5. You Cannot Exceed Setbacks or Height Limits

Singapore’s landed homes must follow strict URA guidelines:

Setback examples:

• Rear: 2m (typically)

• Side: varies for terrace, semi-D, corner terrace

• Front: determined by existing line

Height control:

• 2-storey landed zone

• 2.5-storey mixed landed zone

• 3-storey landed zone

Houses in East Coast (Lucky Heights, Frankel, Opera Estate) often sit in 3-storey zones → more attic flexibility.
Houses in Bukit Timah sometimes fall in 2-storey zones → A&A limits are stricter.

6. You Cannot Build Beyond Allowable GFA (Under A&A)

Large extensions that dramatically increase GFA (Gross Floor Area) cannot be classified as A&A, even if structural elements remain.

3. What BCA Allows Under A&A (2026 Updated Rules)

Below is the most important section: what you can legally do.

1. Internal Configuration Changes

This includes:

• removing non-structural walls

• reconfiguring rooms

• enlarging living or dining space

• converting storage to helper’s room

Common in:

• Thomson Garden Estate

• Seletar Hills

• Serangoon North

These estates often have older segmented layouts that modern families prefer to open up.

2. Small to Medium Extensions

Most common form of A&A.

Rear extensions:

Popular in:

• Telok Kurau

• Opera Estate

• Pasir Panjang

• Kembangan

• Serangoon Gardens

Rear extensions may include:

• kitchen enlargement

• utility area

• new bathroom

• dining room extension

Side extensions (for corner terraces and semi-Ds):

Allowed as long as:

• setback is maintained

• drainage is managed

• structural loading is calculated

Typical in:

• Binjai Park

• Sunset Way

• Lentor private estate

3. Façade Improvements

A&A allows:

• new windows

• new cladding

• new front elevation

• new gate/fencing

• aluminium screen features

• balcony design updates

Façade modernisation is very common in areas undergoing revitalisation, such as:

• Marine Parade (TEL effect)

• Upper Thomson (TEL effect)

• Lentor (new private enclave)

• Beauty World (IT Hub redevelopment)

4. Interior Reworks (Mezzanines, Bathrooms, Etc.)

As long as the structural capacity is confirmed by a PE.

Allowed:

• mezzanine addition (if floor loading is within limit)

• converting void to usable space

• adding bathrooms

• adding skylights

• enlarging staircases

• replacing internal finishes

Homes in Serangoon Gardens, Holland Grove, and Frankel Estate frequently add mezzanines to improve space.

5. Roofing Works (Partial)

BCA allows:

• re-roofing

• upgrading waterproofing

• replacing tiles

• modifying pitch (slightly)

• adding skylights

Full roof reconstruction may trigger rebuild classification.

6. M&E Upgrades

A&A allows replacement of:

• wiring

• plumbing

• aircon trunking

• exhaust ducts

• distribution board

• lighting circuits

Older houses in Thomson, Bedok South, and Serangoon North often require full M&E upgrades.

4. A&A Regulatory Submission Requirements

Even though A&A is not a rebuild, it still requires authority submissions.

Here’s what typically needs to be submitted:

A. BCA Submissions

Required for:

• structural works

• extension works

• façade changes

• roof modifications

• new openings in external walls

PE (Professional Engineer) endorsement is mandatory.

B. URA Submissions

Required if the A&A affects:

• envelope profile

• GFA

• roof form

• external elevation

• attic/mezzanine addition

C. PUB Submissions

Required for:

• drainage

• sewer connection changes

• bathroom addition

This often applies in older estates like Telok Kurau, Seletar Hills, and Siglap.

D. SCDF Submissions

Required when significant internal reconfiguration affects fire escape paths.

5. Special Zones with Stricter A&A Rules

A&A guidelines differ across neighbourhoods depending on planning zones.

1. Conservation-Influenced Areas (Façade Restrictions)

E.g.,

• Joo Chiat

• Mountbatten

• Emerald Hill (though mostly conserved)

Façade alterations must respect area character.

2. Low-Rise Exclusive Zones

E.g.,

• Caldecott Hill

• Brizay Park

• King Albert Park

• Windsor Park

Height limits are tighter → attic and mezzanine works require careful checks.

3. MRT Growth Corridors (Higher Demand for A&A)

Areas near upcoming or recently opened MRT stations often see more A&A works:

TEL:

• Siglap

• Marine Parade

• Bayshore (future)

• Upper Thomson

• Lentor

• Springleaf

CRL:

• Hougang

• Serangoon North

Because homeowners want to upgrade homes before resale as these districts appreciate.

6. When A&A Is Not Recommended

Even if allowed, A&A is not always the best option.

Avoid A&A when:

• structure is severely compromised

• termites have damaged beams

• house sits on unstable soil (Pasir Panjang slopes, parts of Bukit Timah)

• drainage issues require foundation rework

• layout is too inefficient to salvage

• you intend to maximise GFA to the full envelope

In these cases, rebuilding is more cost-efficient long-term.

7. How to Avoid Compliance Problems (Critical Tips)

✔ Do not start demolition before BCA approval

Even partial demolition may be considered unauthorised.

✔ Avoid removing slabs without structural engineer approval

Many owners unknowingly cross into “rebuild” territory.

✔ Ensure neighbour protection works are performed

Terraces in Opera Estate, Telok Kurau, Serangoon Gardens require careful NPW.

✔ Plan M&E early

Older houses often require full rewiring, leaving this late causes delays.

✔ Document every structural decision

For smoother submission and resale documentation.

Useful Links

For homeowners ready to engage experts who ensure full A&A compliance:
🔗 A&A Contractor Singapore

If you're unsure whether your intended changes exceed A&A limits:
🔗 Landed House Rebuild Contractor Singapore
🔗 Tear Down & Rebuild Singapore

To understand the cost implications of different types of A&A:
🔗 How Much Does A&A Work Cost in Singapore?

To explore how far you can extend legally under A&A:
🔗 How to Expand Your Landed Home Legally Using A&A Works

To compare renovation, A&A, and rebuild options:
🔗 Renovation, A&A, or Rebuild, Which Should You Choose?