How Long Does A&A Work Usually Take?

How Long Does A&A Work Usually Take?

If you’re planning A&A (Additions & Alterations) works for your landed home in Singapore, one of your biggest questions is probably:

“How long will the A&A process take from start to finish?”

Homeowners across Singapore, from terraces in Kovan, to semi-Ds in Sunset Way, to older bungalows in Namly, often underestimate how many stages are involved.

A&A work is faster than rebuilding, but still requires approvals, coordination, and sequencing.
This guide breaks down the full A&A timeline in simple, realistic phases, based on actual landed projects across Singapore.

1. Typical A&A Duration in Singapore (2026)

Total Timeline: 6 – 12 Months (On Average)

This includes:

• design

• submission

• approvals

• procurement

• construction

• inspections

• handover

Actual duration depends on:

• home age

• structural complexity

• size of extension

• number of bathrooms added

• neighbourhood access (affects speed)

• engineer involvement

• materials

• monsoon season

2. Full A&A Timeline Breakdown

Below is a realistic, phase-by-phase guide used by contractors across Singapore.

**Phase 1: Design, Consultation & Site Study

(3 – 8 Weeks)**

What happens here:

• homeowner shares requirements

• architect surveys the house

• structural engineer inspects existing beams & columns

• feasibility checks for extensions

• draft space planning

• preliminary A&A concept is created

Why this phase matters:

Older houses in:

• Frankel Estate

• Serangoon Gardens

• Seletar Hills

• Hillview Gardens

• Braddell Heights

• Bedok South / Kew Drive
  often have unpredictable hidden conditions, meaning design must be carefully planned before approval.

Districts where design takes longer:

• Joo Chiat / Mountbatten (heritage sensitivity)

• Pasir Panjang slopes (terrain complexity)

• Bukit Timah old bungalows (drainage & soil conditions)

For simpler terraces (e.g., Opera Estate, Kovan), design is faster.

**Phase 2: Authority Submissions

(4 – 12 Weeks)**

This is the phase most homeowners underestimate.
For any structural A&A work, the following approvals are required:

A. BCA Submission

Required for:

• extensions

• mezzanine

• new openings

• stair changes

• roof works

• structural reinforcement

B. URA Submission

Required for:

• envelope control compliance

• façade changes

• attic changes

• boundary setback adjustments

C. PUB Drainage & Sewer Submission

Especially important if adding bathrooms or extending the kitchen.

D. SCDF (if required)

Mostly for internal reconfiguration affecting escape paths.

Neighbourhoods where submission may take longer:

1. Terrace clusters with shared walls:

• Opera Estate

• Serangoon North

• Lorong Ah Soo / Aster Estate

• Sembawang Springs

• Jalan Chempaka / Upper Changi

Neighbour protection works must be included in submissions.

2. Adjacent to conserved areas:

• Joo Chiat

• Emerald Hill fringe

• Mountbatten

Elevational changes may require additional planning.

3. Sloped or hillside zones:

• Pasir Panjang (Pepys Rd / South Buona Vista belt)

• Hillview / Bukit Timah fringe

Slope stability affects engineering submissions.

**Phase 3: Pre-Construction (Procurement & Site Setup)

(2 – 6 Weeks)**

Activities include:

• selecting tiles, fittings, windows

• ordering carpentry materials

• choosing roofing systems

• preparing site hoarding

• arranging skip bins

• terminating/redistributing utilities

• scheduling workers

• scaffold installation

Neighbourhoods affecting this phase:

• Narrow roads (Joo Chiat, Opera Estate, Thomson Ridge) slow down logistics.

• Sloped roads (Pasir Panjang, Hillview) require safety planning for machinery.

• Large bungalow plots (Namly, Watten, Brizay Park) require more setup time.

**Phase 4: Demolition & Structural Works

(3 – 10 Weeks)**

This is where real transformation begins.

Works include:

• removing non-structural walls

• breaking slabs (where approved)

• opening new windows

• demolishing old bathroom walls

• roof partial demolition

• internal reconfiguration

• building new beams (if required)

• constructing extensions

Factors affecting timeline:

• thickness of old walls

• strength of structural beams

• unforeseen issues (spalling concrete, termite damage)

• neighbour protection measures

Districts where structural phases may be slower:

• Frankel Estate (older structural systems)

• Serangoon Gardens (Mixture of 70s–90s houses)

• Telok Kurau (old foundations, deep plots)

• Hillview slopes (uneven soil profile)

• Bukit Batok / Westwood landed pockets (older RC frame)

Older houses almost always reveal hidden surprises, extending structural works.

**Phase 5: M&E, Plumbing & Wiring

(4 – 8 Weeks)**

This phase covers:

• full re-wiring

• DB board upgrades

• new plumbing runs

• water heater installations

• aircon trunking

• ventilation ducts

Houses requiring longer M&E upgrades:

• Thomson Ridge / Windsor Park (massive internal rewiring)

• Seletar Hills (older copper piping systems)

• Upper Changi & Bedok South (70s-era drainage layouts)

• Pasir Panjang (complex aircon routing due to slope)

**Phase 6: Interior Construction, Carpentry & Finishing

(6 – 12 Weeks)**

Includes:

• tiling

• kitchen carpentry

• wardrobes

• feature walls

• staircase finishing

• glass installation

• paint

• fixtures & fittings

Districts influencing timeline:

• Luxury bungalow zones (Namly, Watten, Holland), higher-spec material selections, custom carpentry → longer timeline.

• Coastal areas (Siglap / Pasir Ris), waterproofing and salt-exposure considerations often take longer.

• Terraces in constricted access zones (Opera Estate, Joo Chiat), material delivery slower, labour sequencing tighter.

**Phase 7: Final Inspection, Defects & Handover

(2 – 6 Weeks)**

Includes:

• defects rectification

• touch-ups

• aircon testing

• waterproofing verification

• plumbing checks

• BCA/URA completion checks (where required)

Factors affecting duration:

• weather (monsoon season delays outdoor works)

• custom carpentry defects

• window alignment issues

• waterproofing tests for new bathrooms

Estates where defects phase can stretch:

• Older houses with uneven slabs causing tile alignment issues

• Terraces with shared walls where neighbour-related issues arise

• Houses on slopes where drainage must be tested thoroughly

3. What Affects A&A Duration Most? (Critical Factors)

1. Age of House

50-year-old structures in areas like:

• Opera Estate

• Serangoon Gardens (older units)

• Thomson Garden Estate

• Bedok South / Kembangan

• Seletar Hills

… typically reveal issues that slow down progress.

2. Type of Extension Planned

Fast A&A:

• internal reconfiguration

• painting

• carpentry upgrades

Moderate A&A:

• rear extension

• bathroom additions

Slow A&A:

• attic enlargement

• mezzanine construction

• major façade redesign

3. Neighbour Protection Works (NPW)

Required for all terraces and many semi-Ds.
NPW adds time, especially in dense estates like:

• Opera Estate

• Serangoon North

• Hougang landed pockets

• Sembawang Springs

• Compassvale Lane landed patch

4. Approval Complexity

Roof changes, façade transformations, and large extensions take longer to approve in:

• conservation-adjacent zones

• sloped districts

• envelope control-sensitive areas like Watten, Namly, Brizay Park

5. Material Choice

Imported tiles, custom aluminium windows, bespoke carpentry extend timelines.

4. Fast vs Slow A&A Projects (Realistic Scenarios)

Fast A&A (6–7 Months):

• small rear extension

• kitchen + bathroom upgrade

• minor façade work

• internal wall reconfiguration
  Common in:

• Kovan terraces

• Serangoon North houses

• Sunset Way semi-Ds

Moderate A&A (8–10 Months):

• major kitchen & dining expansion

• multiple new bathrooms

• mezzanine addition

• attic upgrades
  Common in:

• Telok Kurau

• Opera Estate

• Seletar Hills

• Bedok South landed zone

Complex A&A (11–12+ Months):

• major façade transformation

• roof redesign

• multi-room extensions

• extensive structural strengthening
  Common in:

• Bukit Timah bungalows

• Brizay Park

• Holland / Coronation

• larger Seletar or Springleaf detached houses

Useful Links

For homeowners planning an A&A project and needing timeline clarity:
🔗 A&A Contractor Singapore

If you're deciding between A&A speed vs rebuild duration:
🔗 Landed House Rebuild Contractor Singapore
🔗 Tear Down & Rebuild Singapore

For understanding what affects A&A timelines:
🔗 A&A Guidelines for Singapore Landed Homes, What BCA Allows & Doesn’t Allow

To prepare properly before starting A&A:
🔗 What to Prepare Before Starting A&A Works on Your Landed Home

For planning extensions and expansions:
🔗 How to Expand Your Landed Home Legally Using A&A Works
🔗 Tips to Maximise Floor Area Without Full Rebuild