The 60 sqm Cap — Hard Line, No Wiggle Room

60 sqm internal. That is the absolute limit for a secondary dwelling under the NSW State Environmental Planning Policy (Affordable Rental Housing) 2009. Not 60.5. Not 'we'll see how the certifier feels'. Sixty.

I have watched this number trip up more granny flat clients than any other rule in the SEPP. Last year a Smithfield owner came to Buildana (Lic. 487805C) after their previous draftsman drew a 62.3 sqm layout. CDC certifier kicked it on first review. Three weeks to redraw, re-stamp, and reissue the BASIX. The whole project lost a month before the slab was poured.

Certifiers don't negotiate on this. They measure off the stamped plans at lodgement, and they measure again on site at the occupation certificate. If the on-site internal area exceeds 60, the OC is withheld. No OC = you cannot legally rent it. That is the consequence.

What Counts in the 60 sqm — and What Sneakily Doesn't

Counts toward the 60: every bedroom, the living/dining, kitchen, bathroom, laundry, hallway, linen press, built-in robes, wardrobes, study nook, enclosed entry porch, internal stairs.

Does NOT count: covered alfresco if open on at least one side, uncovered decks, eaves and overhangs, off-street parking, garden sheds under 10 sqm.

The hallway is where most people lose space without realising. A traditional centre-hall layout eats 6-8 sqm of pure circulation. We design around it on every Buildana granny flat — galley plans where the kitchen acts as the corridor, or offset entries that drop you straight into the living area. Same external footprint, 6 sqm more usable space.

Design Tricks That Make 60 sqm Feel Like 75

Covered alfresco. The single biggest one. A 12-14 sqm alfresco open on one side adds outdoor living without consuming an inch of the cap. Tenants in Fairfield, Liverpool and Cumberland pay $20-30/week more for a real outdoor area. We include 10-15 sqm covered alfresco on every detached 2-bed we build in Western Sydney.

European laundry. A cupboard with a stacked washer/dryer saves 3-4 sqm vs a separate laundry room. Compromise on storage, not on bedrooms.

2700mm ceilings instead of 2400. Doesn't count toward floor area but completely changes how the space feels. Cost increment is around $2,800-$3,500 on a 60 sqm dwelling. Worth it on every build.

Sliding stacker doors to the alfresco. Visual extension of the living area when open. Tenants notice — and pay for it.

Built-in robes recessed into bedroom walls vs freestanding wardrobes recovers 1-1.5 sqm per bedroom. On a tight 2-bed plan, that is the difference between a 9 sqm bedroom and a 10.5 sqm bedroom — between 'just fits a queen' and 'fits a queen plus a chair'.

How Certifiers Actually Measure

Two checks. First check is plan-stage. The certifier reviews the architectural drawings and confirms the internal area is at or under 60. They use the stamped survey and the dimensioned floor plan. Any discrepancy = RFI (request for information). RFI = 2-4 weeks delay.

Second check is on-site at occupation certificate. The certifier walks the building with a measure or a laser, checks internal walls match the plan. If walls have shifted during construction, they re-measure. If the new internal area is over 60, you do not get an OC and you cannot rent.

Buildana's internal check happens before the certifier even sees it. Our drafting team measures every layout to 0.1 sqm precision, including hallway niches, linen presses, return walls in showers. Then 0.5 sqm of contingency on top.

Where People Most Often Get Caught Out

Imported floor plans. Someone finds a design online from Queensland or Victoria, where the cap is 80-90 sqm. The layout doesn't transfer to NSW — every internal area number is wrong by 20-30 sqm.

3-bed designs. The SEPP doesn't ban three bedrooms but the maths makes it brutal. Three bedrooms (9 sqm each minimum for marketability) + bathroom (5) + laundry (3) + open-plan living/kitchen (22-26) + circulation (6) = you are already at 62-66. Almost never works as a viable layout.

Architect-drawn 'concept' plans. Some architects draw 'aspirational' layouts that exceed the cap and expect the certifier to be lenient. Certifiers aren't lenient on the SEPP — it isn't a discretionary control.

Late-stage layout changes during construction. Once the slab is poured, the perimeter is fixed. Internal changes (moving a wall to expand a bedroom) almost always tip a tight plan over.

Buildana's free site assessment includes a layout sanity check — we will tell you in 30 minutes whether the layout you have been quoted on actually fits the cap. Contact us.

If the rules are clear and you want to see compliant layouts, our 47 granny flat designs at /homes/granny-flats/designs are all sized to the SEPP — from 35m² studios through to 60m² 2-bedroom plans.

2026 Size Limit — What 60sqm Actually Buys You

The NSW Housing SEPP 2021 caps granny flat internal floor area at 60sqm. That number hasn't moved in 2026 and isn't expected to move in the medium term — but the practical interpretation of 60sqm has firmed up across certifiers and councils. Useful reference points:

What counts toward the 60sqm: • Internal living, dining, kitchen, bedrooms, bathroom, laundry — every internal habitable and wet-area space. • Internal storage rooms and walk-in robes count. • Internal stairs (in the rare two-storey granny flat) count.

What does NOT count toward the 60sqm: • Covered alfresco / patio (subject to council DCP — most LGAs allow up to 12–24sqm covered outdoor space outside the 60sqm). • Carport or garage attached to the granny flat (subject to council DCP). • External eaves and overhangs. • External storage (sheds, garden stores).

Practical 2026 layouts that work within 60sqm: • 1-bedroom open-plan (35–40sqm) — combined living-kitchen-dining, separate bedroom, bathroom. Suits older clients downsizing or single-occupant rental. • 2-bedroom compact (50–55sqm) — combined LKD, two bedrooms (one master with walk-in), bathroom. Best rental yield in our LGAs. • 2-bedroom + small study (58–60sqm) — combined LKD, two bedrooms, bathroom, small study nook. Maxes out the SEPP allowance. • 2-bedroom + separate dining (60sqm, tight) — LKD broken into separate kitchen and dining, two bedrooms, bathroom. Requires very efficient corridor and bedroom layout.

Layouts that don't work within 60sqm: • 3-bedroom granny flat — geometrically impossible without forcing tiny bedrooms. • 2-bedroom + 2-bathroom — possible but compromises bedroom and living space. • Open-plan 60sqm great-room with a single bedroom — feels generous but underutilises the SEPP allowance for rental purposes.

For the full library of compliant layouts: /homes/granny-flats/designs.