Designing a luxury second-storey addition over a heritage home

Answering: How do you add a luxury second storey over a heritage home in Melbourne without losing its character or its planning permit?

Estimated reading time: 9 min read

A luxury second-storey addition over a single-storey heritage home works when the new level is set back behind the original front rooms, sits at or below the existing ridge sightline, and reads as a recessive, secondary form rather than a competing one. In a Heritage Overlay, the City of Melbourne’s heritage design guidance asks that additions be set back behind the principal part of the building and remain “concealed” or “partly concealed” from the street, so the heritage facade keeps its prominence. Get the sightlines, the structure over old footings, and the neighbours’ light and privacy right at concept stage and a first-floor addition is entirely achievable. Across 59 heritage approvals at a 98% success rate, our practice has found the upper level is where these projects are won or lost on the drawing board, not at the council counter.

You have a beautiful period home and a growing need for space: a primary suite, a study, a quiet floor away from the living rooms. Building up feels like the obvious answer, until you realise the front of the house is exactly what the overlay is there to protect.

The good news is that “building up” and “keeping the character” are not opposites. A well-resolved second storey is one you barely see from the footpath and clearly notice from inside, where the volume, the light and the new outlook do their work.

This is the part of the project we resolve before a single elevation is drawn, so the upper level is designed to the constraint rather than against it. Here is how the pieces fit together.

Key Insights

• A second storey over a heritage home should be set back behind the original front rooms and sit at or below the existing ridge, so it stays recessive from the principal street view.
• Councils assess upper-level additions through the Heritage Overlay (Clause 43.01), usually requiring a heritage report and sightline diagrams from the street.
• Building over old footings and load-bearing heritage walls is a structural question to answer early, because the original fabric was never designed to carry a floor above.
• Victoria’s residential development provisions (ResCode at Clause 55, restructured by the 2025 Townhouse and Low-Rise Code reforms) control overlooking and overshadowing — the two neighbour impacts an upper level must resolve.

Keep reading for full details below.

Table of Contents

• Keeping the Addition Invisible From the Street
• The Structural Reality of Building Over Heritage Fabric
• Your Neighbours’ Light and Privacy: ResCode Clause 55
• How the Heritage Overlay Assesses an Upper Level

Keeping the Addition Invisible From the Street

The single most important move in a luxury second-storey addition is keeping it recessive from the principal street view. Heritage councils protect the way the original home presents to the footpath, so the upper level has to step back and step down.

The City of Melbourne’s heritage design guidance puts it plainly: to maintain the prominence of the building, additions should be set back behind the front or principal part of the building, and you should not build over or extend into the air space directly above that front part. The same guidance grades visibility, describing additions as “concealed” when they cannot be seen from a street or public park, and “partly concealed” when some of the higher rear part may be visible provided it does not visually dominate or reduce the prominence of the existing facade in the street. That language is the test your design has to pass.

In practice, three moves do most of the work:

• Set back from the front. The upper level sits well behind the original front rooms, so the parapet or verandah still defines the street.
• Sit below the ridge sightline. Where the new volume can be kept at or below the existing ridge, or partly tucked into the roof form, it disappears from the oblique view a pedestrian actually has.
• Use a lightweight, contrasting form. A clearly secondary, contemporary upper level reads as an addition, not as a second original house.

This is also why councils ask for sightline diagrams. For upper-storey additions, many Victorian schemes require oblique view diagrams from each adjoining street, demonstrating exactly what will and will not be seen. We design those sightlines deliberately from the first sketch, so the recessive outcome is proven, not hoped for.

The Structural Reality of Building Over Heritage Fabric

A heritage home was never designed to carry a floor above it, and that single fact shapes the engineering of every second-storey addition.

Most single-storey period homes in Melbourne sit on shallow brick or stone footings, with solid masonry or timber-framed walls sized for one level and a roof. Adding a storey introduces loads those original elements were not built for, so the structural strategy has to be resolved before the architecture is locked, not retrofitted afterwards. Barbara’s roughly ten years lecturing Building Science at RMIT and the University of Melbourne sit behind exactly these decisions: how load actually travels through old fabric, and where it can and cannot go.

The realistic options usually fall into a few approaches:

• Upgraded or new footings. The existing footings are assessed and, often, supplemented or replaced to carry the additional load.
• A transferred or independent structure. New steel or a structural frame carries the upper level down to new footings, so the original walls are relieved rather than overloaded.
• Protecting the fabric you keep. Where original walls remain, the design avoids cutting into significant fabric and detailing that the heritage assessment will later scrutinise.

None of this is exotic, but all of it is unforgiving if it is discovered late. A structural engineer engaged at concept stage, working alongside the architect rather than after, is what keeps the budget honest. Across more than 200 permit applications, our role is to bring the structural reality into the room early, so the design you fall in love with is one your footings can actually carry, with fixed-fee certainty rather than a nasty surprise mid-build.

Your Neighbours’ Light and Privacy: ResCode Clause 55

A second storey changes more than your own home; it changes what your neighbours see and how much sun they keep. In Victoria, those impacts are governed by ResCode, the residential development standards at Clause 55 of the planning scheme.

Two standards do most of the work on an upper-level addition. The overlooking standard protects neighbours from being seen into: a new habitable-room window, balcony or deck should be designed to avoid direct views into the secluded private open space and habitable-room windows of a nearby dwelling — broadly, within around 9 metres — using screening, sill heights or careful placement to the extent the current provisions require. The overshadowing standard protects their sunlight: an upper level should not cast unreasonable new shadow over a neighbour’s secluded private open space at the equinox. The exact test was reset by the 2025 Townhouse and Low-Rise Code reforms to Clause 55, so the standard that applies depends on your site and project — which is why we check it against the current provisions rather than a rule of thumb.

In design terms, that translates into a handful of reliable moves:

• Orient and position upper-level windows away from a neighbour’s private open space, or screen and splay them.
• Raise sill heights or use highlight windows where an outlook would otherwise overlook.
• Test the shadow diagram at the equinox early, and pull the form back where it would clip a neighbour’s protected light.

These standards are also where a project meets, or avoids, objections. Much of the value of resolving overlooking and overshadowing inside the design is that a neighbour with their privacy and light intact is far less likely to object, which keeps the application on its statutory clock rather than heading toward VCAT.

How the Heritage Overlay Assesses an Upper Level

All of the above comes together under one approval: the planning permit assessed against the Heritage Overlay at Clause 43.01 of your planning scheme.

Within a Heritage Overlay, a planning permit is generally required for external alterations, additions and new construction, and the application is judged on its impact on the significance of the heritage place. Councils typically require a report from a suitably qualified heritage consultant assessing that impact, and for upper-level work, the sightline diagrams that show how the addition reads from the street. The recurring test, set out in council heritage policy such as the City of Boroondara’s, is that an addition should be visually recessive and read as a secondary element to the heritage place, located to the rear where possible.

Whether your building is contributory or individually significant shifts how much room you have. A contributory home is valued for the way it supports a precinct, so the assessment leans on the streetscape reading, and there is often genuine scope for a well-set-back upper level. An individually significant home is protected more tightly in its own right, so the principal elevations and original fabric carry more weight, and the design argument has to be that much more careful.

This is where designing to the overlay, rather than fighting it, pays off. Our practice has navigated 59 heritage approvals across more than ten Victorian councils including Boroondara, Stonnington, Port Phillip and Bayside, and the pattern holds: the upper level that is set back, kept below the ridge and clearly subordinate is the one that clears the overlay cleanly. Constraints, read early, tend to reveal the design rather than restrict it.

Closing

A luxury second storey over a heritage home is never just extra floor space; it is a set of constraints resolved well. Set the addition back, keep it below the ridge, carry the load on structure your old footings can actually take, protect your neighbours’ light and privacy, and argue the heritage case on recessiveness, and you gain the space without losing the home. For a deeper look at how we resolve these questions before design begins, visit our process page.

Frequently Asked Questions

Q: Can you add a second storey to a heritage home in Melbourne?

A: In most cases, yes. Within a Heritage Overlay you generally need a planning permit, and the upper level must be designed to stay recessive: set back behind the front rooms, at or below the existing ridge sightline, and clearly subordinate to the heritage facade. Whether your home is contributory or individually significant changes how much scope you have, which is why we confirm the listing before designing.

Q: Will the council reject a first-floor addition over a period home?

A: Not if it is designed to the overlay. Councils assess upper-level additions under Clause 43.01 on their impact on the heritage place, usually requiring a heritage report and sightline diagrams from the street. An addition that is set back, sits below the ridge and reads as a secondary element is the kind that clears the overlay. The refusals tend to be the ones that dominate the original facade.

Q: How does a second storey affect my neighbours under ResCode?

A: ResCode (Clause 55) protects neighbours from overlooking and overshadowing. New upper-level windows must avoid direct views into a neighbour’s secluded private open space, and the addition must not cast unreasonable new shadow over it. The precise standards were restructured by the 2025 Townhouse and Low-Rise Code reforms, so we test both against the current provisions early, which keeps the design respectful of neighbours and avoids objections that can stall an application.

Q: Is building over old footings and walls a problem?

A: It is a question to answer early, not a barrier. A single-storey heritage home was not built to carry a floor above, so the structural strategy, whether upgraded footings, new footings or a transferred frame, is resolved at concept stage with an engineer. Across more than 200 permit applications, we bring that structural reality into the design from the start, so the budget stays honest.

Want to Learn More?

With more than 35 years designing within Melbourne’s heritage suburbs, BY Projects Architecture treats the upper level as a design problem to resolve, not a gamble to take. The more honestly the constraints are read at the start, the better the home is built for living, not just photos.

Citations

• “Heritage design guide — Additions” — City of Melbourne. Confirms additions should be set back behind the front or principal part of a heritage building, must not extend into the air space above it, and grades visibility as “concealed” or “partly concealed” so the addition stays subordinate to the street facade. https://www.melbourne.vic.gov.au/heritage-design-guide-additions
• “Demolition, buildings and works in a Heritage Overlay” — Yarra City Council. Confirms that under Clause 43.01 a planning permit is generally required to demolish or remove, externally alter, extend or construct a building on land in a Heritage Overlay. https://www.yarracity.vic.gov.au/planning-and-building/planning-permits/guides-and-resources/demolition-buildings-and-works-heritage-overlay
• “PPN27: Understanding the residential development provisions” — Planning Victoria. Explains Victoria’s residential development provisions (ResCode) for overlooking and overshadowing of neighbours; these Clause 55 standards were restructured by the 2025 Townhouse and Low-Rise Code reforms. https://www.planning.vic.gov.au/guides-and-resources/guides/planning-practice-notes/understanding-the-residential-development-provisions
• “Local Planning Policy — Heritage (Clause 22.03)” — City of Boroondara Planning Scheme. Confirms council heritage policy that additions should be visually recessive, read as a secondary element to the heritage place, and be located to the rear where possible. https://www.boroondara.vic.gov.au/sites/default/files/2017-05/Amendment-C229-clause22_03-exhibition.pdf

These are the Victorian sources that govern a second-storey heritage addition: the Heritage Overlay at Clause 43.01 and council heritage policy for the design assessment, and ResCode at Clause 55 for the impact on neighbours.

With 35-plus years and 59 heritage approvals across Melbourne’s councils, our work on a second-storey addition is to resolve the sightlines, the structure and the neighbours before the first elevation is drawn, so you gain the space and keep the home you fell for.

About the Author

Barbara Yerondais, FRAIA, is the founder of BY Projects Architecture. With 35+ years of experience, she specializes in sustainable, community-focused design and heritage restoration. A dedicated mentor and rower, Barbara balances her high-impact Melbourne practice with a passion for social inclusion and passive, energy-saving design.