What to Prepare Before Starting A&A Works on Your Landed Home

What to Prepare Before Starting A&A Works on Your Landed Home

Whether you're planning to expand your terrace in Serangoon North, modernise a semi-D in Sunset Way, or update a bungalow in Watten Estate, A&A (Additions & Alterations) is one of the most effective ways to upgrade your home without committing to a full rebuild.

But many homeowners jump straight into renovation mode without understanding the critical preparation steps needed before A&A works begin.
This often leads to delays, unnecessary cost increases, miscommunication with contractors, and approval issues with BCA/URA.

This guide gives you a complete Singapore-specific A&A preparation checklist, with examples across landed neighbourhoods island-wide.

1. Assess the Current Condition of Your Home (Very Important for Older Houses)

Before any design or extension work, you need a realistic understanding of your home’s existing structure, wiring, plumbing, and soil condition.

✔ Common issues in older estates:

• Frankel Estate & Opera Estate: aging RC frames, old sewer lines

• Serangoon Gardens: inconsistent beam sizes in 70s–80s houses

• Upper Thomson / Jalan Leban: ageing roof structures

• Seletar Hills: termite exposure in timber roof members

• Pasir Panjang slopes: soil stability concerns

• Kembangan landed pockets: old water piping and low internal ceilings

A proper assessment helps determine:

• whether A&A is enough

• if certain works risk crossing into “rebuild” territory

• whether structural strengthening is needed

• whether M&E replacement is mandatory

Who conducts the assessment?

• architect

• structural engineer (PE)

• site inspector

This step ensures your A&A plan is realistic and compliant.

2. Prepare a Clear List of Needs vs Wants

One of the biggest time-wasters in A&A planning is unclear homeowner expectations.

Create a simple list of what you must have and what you would like to have.

Common “MUST HAVES” among Singapore homeowners:

• larger kitchen (especially families upgrading from condos)

• extra bathroom

• helper’s room

• more natural light

• bigger living-dining area

• better ventilation

• safer staircase (older homes often have steep steps)

Common “GOOD TO HAVE” features:

• attic lounge

• walk-in wardrobe

• extended balcony

• mezzanine study

• sliding glass façade

• modern front elevation

Neighbourhood examples:

• Lentor / Springleaf: many owners want bigger back-of-house service areas

• Serangoon Gardens: families want larger dining + kitchen spaces

• Seletar Hills: patio-to-indoor conversions common

• Pasir Ris landed: popular to add more bathrooms due to large families

Knowing your priorities prevents budget creep later.

3. Check Zoning, Height Limits & Envelope Control Early

Many homeowners assume “anything is possible” under A&A, until they meet URA rules.

Key restrictions to check:

• maximum height allowed

• attic restrictions

• roof profile limits

• front/back/side setbacks

• conservation influence zones

• whether basement works are allowed

Different neighbourhoods = different restrictions:

• Opera Estate / Frankel: 3-storey landed zone → A&A attic potential

• Serangoon Gardens: mix of 2 and 2.5-storey zones → attic must follow profile

• Watten Estate / Bukit Timah: stricter envelope controls

• Joo Chiat / Mountbatten: elevation must respect local character

• Pasir Panjang slopes: envelope profile interacts with terrain

Confirming envelope control ensures you plan legal extensions.

4. Set a Realistic Budget (Including a Safety Buffer)

A&A typically costs between $200,000 – $600,000+ depending on property type and complexity.

Typical budgets by neighbourhood type:

• Inter-terrace (Kovan, Opera Estate): $200k–$350k

• Semi-D (Sunset Way, Serangoon Gardens): $300k–$500k

• Bungalows (Namly, Holland, Windsor): $500k–$900k+

Always include:

• 10–15% contingency buffer

• fees for PE submissions

• NPW (Neighbour Protection Works)

• additional waterproofing

• replacement of old wiring & plumbing

• new windows & glazing

Older houses almost always uncover surprises.

5. Engage the Right Team Early (Architect + PE + Contractor)

A&A is more complex than renovation, you cannot rely on just an interior designer or a carpenter team.

Minimum team required:

• Architect, design + URA submission

• Structural Engineer (PE), structural drawings + BCA submission

• Contractor experienced with landed homes

Why this matters:

Projects in:

• Thomson Ridge (older beams)

• Hillview (slope houses)

• Kembangan (drainage issues)

• Serangoon Gardens (irregular plots)
  require expertise beyond carpentry and interior design.

6. Conduct Pre-Submission Feasibility Checks

Before URA/BCA submissions, confirm the following:

✔ Internal load calculations (if adding mezzanine)

Terraces in Telok Kurau and Opera Estate often add mezzanines.

✔ Roof load capacity

Especially for older roofs in:

• Seletar Hills

• Serangoon Gardens

• Bedok South

✔ Sewer alignment checks

Common in older estates like:

• Frankel

• Pasir Panjang

• Braddell Heights

✔ Feasibility of extension footprint

Ensure setbacks are sufficient.

7. Prepare for Authority Submissions (Must Not Be Overlooked)

A&A requires formal approval before work begins.

Authorities involved:

• URA, architectural approval

• BCA, structural safety

• PUB, drainage & sewer

• SCDF (if fire escape paths affected)

Submission time typically:
4–12 weeks, depending on complexity.

Longer submission times occur in:

• conservation-adjacent neighbourhoods

• slope districts

• homes undergoing attic/roof changes

Examples:

• Joo Chiat (façade sensitivity)

• Hillview slopes (soil stability)

• Pasir Panjang ridgeline (drainage complexity)

8. Plan for Temporary Relocation (If Necessary)

Homeowners often ask:

“Can I stay in the house during A&A?”

Realistically, staying is harder than expected.

Houses where staying is difficult:

• older terraces (very dusty during wall hacking)

• homes with major kitchen rework

• houses where walls are being reconfigured

• multi-bathroom upgrades

• major M&E replacement

Neighbourhood examples:

• Telok Kurau terraces (deep houses → dust travels far)

• Frankel older houses (major plumbing replacement)

• Serangoon North terraces (multiple bathroom A&A)

Temporary relocation helps speed up work and reduce stress.

9. Prepare a Detailed Material & Fixture Selection List

Finalising materials early prevents delays later.

Key items to choose ahead of time:

• floor tiles

• bathroom fittings

• window systems

• carpentry finishes

• lighting plan

• aircon type (multi-split vs VRV)

• kitchen appliances

Estates where custom windows are common:

• Pasir Ris landed (wide façades)

• Upper Thomson terraces (deep front elevation)

• Braddell Heights (modern façade upgrades)

• Sunset Way (semi-D façade redesigns)

Material procurement often takes 4–6 weeks.

10. Consider Long-Term Plans (Future-Proofing Through A&A)

Many Singapore homeowners today want homes that support multi-generational living, hybrid work, and flexible layouts.

Future-proofing ideas:

• add ducting & space for a future lift shaft

• design a room convertible into elderly suite

• ensure M&E supports EV charger

• plan for solar panel installation

• create flexible study spaces

• allow for future attic upgrade

Great for homes in:

• Marine Parade (TEL accessibility increases rental appeal)

• Bukit Timah (multi-gen demand)

• Lentor (family-focused buyers)

• Serangoon Gardens (large-family neighbourhood)

11. Notify Your Neighbours Early

This is a simple but often skipped step.

Why important:

• NPW (Neighbour Protection Works) may require access

• hammering and hacking noise is unavoidable

• scaffold may run near boundaries

• drainage modifications may temporarily affect shared access

Neighbourly goodwill helps avoid complaints and delays, especially in dense terrace estates like Opera Estate, Serangoon North, and Hougang landed pockets.

12. Understand the Realistic A&A Timeline

Typical A&A duration:
6–12 months

Breakdown:

• Design: 3–8 weeks

• Submission: 4–12 weeks

• Construction: 4–8 months

• Handover: 2–6 weeks

Longer timelines expected for:

• houses on slopes

• extensive bathroom additions

• attic changes

• façade transformations

• old wiring/plumbing replacement

13. Prepare Mentally for Noise, Dust & Changes

A&A is not light renovation, it is a full construction project.

Expect:

• daily hacking (initial weeks)

• cement smell

• dust circulation

• noise during working hours

• temporary service downtime

This is particularly noticeable in long, narrow terraces like Telok Kurau and Pasir Ris landed.

Useful Links

For full professional A&A planning support:
🔗 A&A Contractor Singapore

If you're preparing for A&A but unsure about legal limits:
🔗 A&A Guidelines for Singapore Landed Homes, What BCA Allows & Doesn’t Allow

For cost-related planning:
🔗 How Much Does A&A Work Cost in Singapore?

To understand the full A&A timeline:
🔗 How Long Does A&A Work Usually Take?

For homeowners considering a rebuild instead of A&A:
🔗 Landed House Rebuild Contractor Singapore
🔗 Tear Down & Rebuild Singapore

To explore strategies for maximising space:
🔗 Tips to Maximise Floor Area Without Full Rebuild
🔗 How to Expand Your Landed Home Legally Using A&A Works