1-Bedroom granny flats in Frankston & the Peninsula.
The classic granny flat. 35–50m² of self-contained living for an ageing parent, an adult child, or a rental tenant. The most common build we do — and the format that uses the 10-day VicSmart fast-track approval most often.
What a 1-bedroom granny flat actually is.
A standalone self-contained dwelling on the same lot as the existing house. Open-plan kitchen and living, one bedroom, one bathroom, separate entry, own letterbox if practical. Floor area 35–50m² (anything under 60m² uses the VicSmart fast-track in Frankston City). NCC 2022 / 7-star NatHERS compliant by default.
Modular vs custom on-site.
Modular ($90K–$130K all-in): Factory-built in 6–8 weeks, delivered on truck, craned into position in a day. Standard floor plans, standard finishes, faster build, cheaper. Best for Carrum Downs, Seaford, standard suburban blocks where time and cost matter more than custom architectural fit.
Custom on-site ($130K–$180K all-in): Built in place over 14–20 weeks. Bespoke floor plan, finishes match the main house, can tuck into awkward block geometry. Best for Mt Eliza, Frankston South, Mornington heritage areas where the granny flat needs to belong with the main house aesthetically.
What’s included in our 1-bedroom spec.
- Slab: 100mm reinforced waffle pod or stiffened raft (engineer-designed to site class)
- Frame: Pine 90mm wall studs with R2.5 batt insulation, R5.0 ceiling
- Cladding: Choice of Hardies Linea, Colorbond, or render-on-blueboard to match main house
- Windows: Double-glazed aluminium framed throughout (required for 7-star NatHERS)
- Kitchen: Full kitchen with 600mm electric oven, induction cooktop, dishwasher, fridge cavity, pantry
- Bathroom: Walk-in shower, vanity, toilet, exhaust to outside, IP44 lighting
- Heating/cooling: Single-zone ducted reverse-cycle or split system (depending on layout)
- Floors: Hybrid vinyl plank or carpet (your choice) to bedroom and living
- Electrical: Separately metered, separate switchboard, 15+ outlets, USB outlets in kitchen and bedroom
- NatHERS: 7-star pre-assessment included; as-built rating issued on handover
- Warranty: 6-year structural + 12-month defects
What can blow the budget.
- Site fall > 1.5m across the build footprint — requires retaining + extended slab
- Major services upgrade (older 60-amp switchboard, undersized water main)
- Tree Protection Zone (TPZ) on a regulated tree near the build area
- Coastal AS 4312 zone (Mt Eliza, Mornington, parts of Seaford)
- BAL bushfire rating (eastern Peninsula — Red Hill, Main Ridge etc.)
- Heritage Overlay design controls (Mornington Park, Mt Eliza heritage precincts)
We do the site visit before quoting so all of these are caught in the fixed price — not in a variation later.
Where we work.
Free 1-bedroom design consultation.
On-site visit. Concept drawings + fixed quote in 7 days.