2-Bedroom granny flats in Frankston & the Peninsula.

Couples and parents-plus-child.

A 1-bedroom doesn’t cut it for two unrelated people. A 2-bedroom granny flat with bedrooms at opposite ends gives parents and a teen, two siblings, or carer-plus-client real separation. Privacy matters more than floor area. Most 2-bed plans we design have a 9–12m² second bedroom — enough for a single bed, wardrobe, desk.

Long-term rental returns.

A 2-bedroom self-contained on the Mornington Peninsula rents long-term at $480–$650/week in 2026 depending on suburb. A $180K all-in 2-bed modular at $550/week = $28,600 gross rental p.a., ~$22K net after expenses. 7–9 year payback period before capital gain. The numbers don’t work on a 1-bed at $400/week rent; they do work on a 2-bed.

The planning permit reality.

Almost all 2-bedroom builds exceed the 60m² VicSmart limit and need a full planning permit. Expect 60–90 days for Frankston City, 90–120 days for Mornington Peninsula Shire (especially overlay-affected sites). The permit cost is in the $4K–$8K range. We sequence the design, NatHERS pre-assessment, and permit lodgement to overlap with the build prep so total project time is 6–9 months.

Modular 2-bed vs custom 2-bed.

• Modular 2-bed 60–75m²: $140K–$185K. Most factories produce a single core 2-bed plan with 2–3 variations. Faster, cheaper. Crane access required (won’t fit tight Carrum Downs blocks).
• Custom on-site 2-bed 70–90m²: $180K–$220K. Bespoke floor plan, architectural match to main house, fits any block geometry. Best for Mt Eliza, Frankston South, Mornington heritage areas.

2-bedroom standard spec inclusions.

Same as 1-bed but bigger, plus:

• Two bedrooms (typically 11m² main, 9m² second)
• Walk-in robe in main bedroom where layout allows
• Larger bathroom (often with separate WC for two-bedroom rental flexibility)
• Larger kitchen (1800mm bench instead of 1500mm)
• Separate dedicated parking bay (Frankston City + Peninsula Shire both require)
• Second-zone ducted heating where layout is >9m end-to-end