URA's conservation guidelines govern every conserved building in Singapore, and since 1989 that has meant almost 100 conservation areas involving over 7,000 buildings. They rest on one principle, maximum Retention, sensitive Restoration and careful Repair, and any works to a conserved building need Conservation Permission from URA before they start.
Everything below is taken from URA's and the National Heritage Board's own pages, linked at each point. URA revises these guidelines regularly: its Historic Districts page was last updated on 26 June 2026 and its submission process page on 13 July 2026. Treat this guide as a map of how the rules fit together, and read the current page for your conservation area, plus any Specific Restoration Guidelines for your street, before you design anything.
What counts as a conserved building
Conservation in Singapore is a planning control. According to URA's account of its conservation programme, 10 conservation areas were gazetted on 7 July 1989, among them Chinatown, Little India, Kampong Glam, Boat Quay, Clarke Quay, Cairnhill and Emerald Hill, with a total of over 3,200 buildings. The programme has grown since then to almost 100 conservation areas and over 7,000 buildings across the island.
Whether a particular building is conserved is a question of fact, not of appearance. A shophouse can look entirely traditional and not be conserved, and a plain-looking building can be. Check the address on URA's Conservation Portal, which lists each conservation area and building with its history and the guidelines that apply.
URA groups conservation areas into four kinds, and the rules differ markedly between them:
| Category | Examples URA gives | How strict |
|---|---|---|
| Historic Districts | Boat Quay, Chinatown, Kampong Glam, Little India | The strictest. The whole building is conserved. |
| Residential Historic Districts | Blair Plain, Cairnhill, Emerald Hill | Main building conserved; a rear extension below the main roof is allowed. |
| Secondary Settlements | Geylang, Joo Chiat | Conserved on a streetscape basis; taller rear extensions allowed, area by area. |
| Bungalows | Detached residential buildings | Main bungalow conserved; new extensions recessed and kept to the rear where possible. |
The shophouse is the building type most people mean when they search for these rules, so most of what follows uses the Historic Districts guidelines, which are the strictest, and then shows where the other three categories relax them.
Conserved buildings and National Monuments are different regimes
These two are often confused, and they are administered by different agencies. Conserved buildings sit with URA, under the planning system, and are controlled through Conservation Permission. National Monuments are gazetted for preservation, and the Preservation of Sites and Monuments division of the National Heritage Board is the national authority that advises on their preservation and maintenance, guided by the Preservation of Monuments Act. URA's own history of the programme records the first eight National Monuments, including Thian Hock Keng, the Armenian Church and Sri Mariamman Temple, being given legal protection in 1973.
The practical difference is the degree of change allowed. National Monuments carry the highest level of protection. Conservation allows a building to be adapted for modern use, with rear extensions, mezzanines and lifts, provided the parts that give it its character are retained. If your building is a National Monument, speak to NHB before you speak to anyone else. Everything else in this guide is about URA conservation.
The 3R principle, in URA's words
URA's conservation principles describe the 3R as the fundamental principle applicable to all conserved buildings, whatever their scale: "maximum Retention, sensitive Restoration and careful Repair". Four rules follow from it, and between them they decide most design questions on a conservation project:
- Keep the original fabric. All original structural and architectural elements are to be retained and restored. Selective replacement is considered only when absolutely necessary, and total reconstruction runs against the principle.
- Replace one for one, and only with clearance. Where an element must go, for example because it contains asbestos, the owner seeks URA's clearance for a one-to-one replacement.
- Strengthen rather than rebuild. When a building is adapted to a new use, the existing structure is retained by strengthening and repairing it, in the most sympathetic and unobtrusive way, using original methods and materials wherever possible.
- Document before, and during. URA asks for a thorough research and documentation exercise on the building before any conservation work begins, so that restoration is faithfully carried out, and for the technical aspects of the work to be documented at every stage.
That last rule is the one owners most often underestimate. It is not a formality. You cannot retain and restore an element you have not recorded, and once the strip-out begins the evidence of what was there goes into a skip.
What the guidelines protect in a shophouse
The Historic Districts guidelines go element by element. A summary of the ones that shape a renovation most:
| Element | What URA requires |
|---|---|
| Main roof | Original profile, pitch, height, party wall and eaves projection retained. Small, V-profile, unglazed, natural colour clay tiles. |
| Timber floors | Existing level, timber floor and structural system of the upper storeys retained and restored. Voids of up to 25% of the floor area may be introduced; localised reinforced concrete is permitted for toilets and kitchens. |
| Party walls | Load-bearing walls retained. The first 3 m of the party wall behind the first-storey shopfront is kept, and openings must total less than 50% of the wall's length. |
| Front facade | Original fanlights, windows, doors, vents, balconies and verandahs retained and restored, along with ornamental plasterwork, tile work and intact dado panels. Balconies and verandahs stay open. |
| Five-foot way | Original granite slabs retained and restored. Non-slip flooring, no high-gloss finish, a level difference of no more than 175 mm and ramps no steeper than 1:10. |
| Airwell | Original size and location retained, with its original windows. A new roof is allowed below the main roof eaves, in lightweight transparent or translucent material. |
| Rear court | A new roof is allowed, no higher than the second-storey floor level. |
| Staircase | May be retained or relocated. Where the building has timber floors, a new stair must be lightweight, timber or metal: a new reinforced concrete staircase is not allowed. |
| Pintu pagar and screens | Existing pintu pagar and traditional timber screens retained; new ones follow traditional design. |
| Plaster and paint | Lime plaster and lime wash, or modern equivalents such as mineral paint. Spray-applied textured coatings are not allowed. |
Read the timber floor rule twice. URA calls the timber floor one of the key architectural elements of a shophouse, which means the floor levels, the joists and the beams that carry them are part of what is being conserved. Those are also the dimensions that are hardest to find on paper for an old building, and the first ones a structural engineer will ask for.
What you are allowed to add
Conservation is not a freeze. The same Historic Districts page sets out what can be introduced, with dimensions:
- Roof mezzanine. Set back at least 1,500 mm from the inner face of the front facade wall if it is not lower than the top of the uppermost windows, or at least 2,500 mm if it is lower.
- Skylights and solar panels. On the rear slope of the main roof, covering no more than 30% of that slope between them, with skylights protruding no more than 150 mm beyond the tiles.
- Structures on a flat roof. Single-storey, set back at least 3 m from the front and side street elevations, with all structures on the flat roof covering no more than 35% of its area.
- Lifts. Within the building envelope; a shaft that rises above the roof goes on the rear slope or a secondary roof, below the ridge.
- False ceilings, secondary windows, canopies. False ceilings no lower than the original window openings; a secondary layer of windows or doors behind the originals; door and window canopies projecting no more than 450 mm.
- Air-conditioning. Condensing units integrated at the rear, in a recess within the rear boundary wall.
The other three categories are more generous at the rear. In Residential Historic Districts a new rear extension must be lower than the main roof, may not exceed the 3 storeys allowed for landed housing, and needs a minimum 3 m rear setback where it abuts a neighbouring property. In Secondary Settlements, URA sets the height of new rear extensions area by area, from up to 4 storeys for Tiong Bahru shophouses and up to 6 in Balestier to up to 10 in River Valley, with a minimum 600 mm gap between the conserved main building and the new block. For conserved bungalows, new extensions are recessed from the front facade line, kept to the rear wherever possible, and may not directly abut the original building.
Change of use
Shophouse renovations often go hand in hand with a new tenant, and a new use is its own approval. URA's page on the use of buildings in conservation areas says change of use applications are submitted through GoBusiness Singapore, with a processing fee of $500 and a processing time of about 10 working days. It also says the Change of Use Lodgement Scheme, the quicker route available elsewhere, does not apply to conserved buildings in Historic Conservation Areas.
Two restrictions catch people out. In the core areas of Chinatown, Kampong Glam and Little India the first storey has to be for activity-generating uses such as shops. And URA does not allow new bars, pubs, nightclubs, karaoke lounges, massage establishments or spas. Some permitted uses come with their own conditions: a residential use, for instance, is capped at 6 occupants with a minimum 3-month stay and 10 sq m per person.
How Conservation Permission is applied for
URA's submission process for additions and alterations and Category 3 works is explicit that no works should be carried out before Conservation Permission is issued. Who can submit depends on how much the works affect the building's character:
| Category | Typical works | Who submits | URA's stated timing |
|---|---|---|---|
| Category 1 | Roof restoration, restoring facade elements, new rear extensions, structural strengthening | A Qualified Person who is a Registered Architect | Decision within 20 working days |
| Category 2 | Roof tile replacement, new windows or doors, adding a lift or staircase | A Qualified Person who is a Registered Architect or a Professional Engineer | Decision within 20 working days |
| Category 3 | Minimal, localised repair and maintenance: one-for-one tile replacement, painting, security grilles | Owners and contractors; no Qualified Person needed | About two weeks; no fee |
Category 1 and 2 submissions go to URA through CORENET. Conservation Permission is not the end of the approvals either: URA's page says the architect should then submit building plans to BCA and obtain Building Plan approval. So a conservation project runs through two agencies, in that order, before work starts on site. Our guide to A&A works in Singapore sets out the wider approval sequence.
For a conserved building, URA asks for the following to be included in a Category 1 or 2 submission:
- 1 set of Measured Survey Drawings with a registered Surveyor's endorsement
- 1 set of Structural Report from a Professional Engineer
- 1 set of Calculation Plans
- Photographs of the existing front, rear, side (if any), elevation and roof
The same page says the architect should also submit a detailed structural investigation report, including pictures of the building's exteriors and interiors, with a method statement and protection plan prepared and endorsed by the engineer. Read the list as a whole and it describes one job done early: an accurate, endorsed record of the building as it stands, which the architect and the engineer then design and calculate against.
Maintenance, and works next door
Conservation obligations do not end at completion. URA's circular of 1 March 2023 on A&A works to or near conserved buildings says conserved buildings should be regularly maintained so that they remain structurally safe, names the common defects (spalling concrete, cracks in masonry, timber rot and water leakage), and tells owners to engage a Professional Engineer or other suitably qualified professional to rectify them. It also asks Qualified People proposing works to or near a conserved building to factor in its vulnerability when choosing the structural and foundation system, and to propose protective measures for it. A condition record made before neighbouring works start is the simplest evidence of what that protection was meant to preserve.
The Conservation Technical Handbooks
The guidelines say what to keep. The Conservation Technical Handbooks, produced by URA with the Singapore chapter of the International Council on Monuments and Sites (ICOMOS), explain how to restore it. There are eight volumes, free to download: Introduction, Roofs, Facades, Structure, Windows and Doors, Interior Elements, Paints and Coatings, and Managing Change. URA's stated aim is to promote better quality restoration projects and raise competency in the heritage building industry. If your contractor has not read the Roofs and Structure volumes, ask them to.
The Architectural Heritage Awards
URA's Architectural Heritage Awards, established in 1995, recognise well-restored monuments and conserved buildings. The current awards include the Award for Conservation, Conservation & Innovation, New Design in Heritage Contexts and Special Mention, alongside the Architectural Heritage Legacy Award. A project must have been occupied or in viable use for at least one year after its TOP or CSC clearance; largely interior design projects are not eligible, and projects with unauthorised use, illegal works or unresolved planning issues are excluded. Owners aiming for an award should know that the submission is judged on technical excellence in what was conserved, which is far easier to demonstrate with a record of the building before work began.
Why conservation work starts with measurement
Every rule above assumes you know what the building is: the true roof profile and pitch, the party wall lengths and openings, the level of each timber floor, the size and position of the airwell, the facade ornament you are required to keep. For a shophouse built a century ago, those facts are rarely on paper. As our BCA plan purchase guide explains, plans submitted before about 1970 largely sit in the National Archives on microfilm, and a microfilm frame is a historical document, not something an architect can dimension. Where later plans do exist, they record what was approved, not what decades of alterations left behind. Our guide to a floor plan that is missing or wrong covers that situation in general.
A 3D laser scan answers it directly. It records the whole building, inside and out, as a point cloud: facade ornament, roof line, every floor level, the party walls, the stair, the five-foot way. From that capture we produce measured drawings, meaning plans, elevations and sections at the scale the architect needs, and where URA asks for the measured survey drawings to carry a registered Surveyor's endorsement, our partner Registered Surveyor endorses them. Where the architect works in Revit, the same capture becomes a model through Scan-to-BIM. The point cloud also serves the 3R principle in a way drawings cannot: it is a permanent, measurable record of the original elements before anything is removed, which is exactly the research and documentation URA asks for before conservation work begins.
We have done this on a three-storey conservation shophouse in Tanjong Pagar, for a conservation practice. We captured the interior, the five-foot way and the facade with a handheld SLAM scanner, starting each walk outdoors with RTK fixed so the whole building landed in one georeferenced frame, at around 3 cm absolute accuracy and roughly 1 cm relative accuracy in the details conservation cares about: mouldings, air vents, pintu pagar hinges and stair balustrades. The practice received a colourised point cloud in LAS, E57 and RCP, a textured mesh of the facade for elevation drawings and condition annotation, and sections cut from the cloud wherever the existing record was out of date.
One boundary, stated plainly. We produce documentation, not approvals. The Conservation Permission submission is made by your Qualified Person, the structural report is the Professional Engineer's, and the decision is URA's. What we change is the starting point: your architect and engineer design against a measured building instead of an assumed one.
A sensible order of work
- Confirm the building's status and conservation area on URA's Conservation Portal.
- Read the guidelines for that category of area, and any Specific Restoration Guidelines for the street.
- Record the building as it stands, before strip-out: a measured survey, photographs of the front, rear, sides, elevations and roof, and a condition record of original elements.
- Have the Professional Engineer carry out the structural investigation against that record.
- Let the architect prepare the Category 1 or 2 submission, obtain Conservation Permission, then BCA Building Plan approval.
- Apply separately for any change of use, and only then start work, documenting each stage as you go.
If you are at step three, send us the address, the number of storeys and what your architect has asked for. We will tell you what the survey needs to cover and what it would cost.