Size is the question most prefab house buyers get wrong on the first attempt. Too small and daily routines feel restricted; too large and build costs, transport logistics, and site requirements climb unnecessarily. The right floor area depends on how many people will occupy the space, how it will be used day to day, and what the delivery site can physically receive. This guide uses three real Cammihouse models to show exactly where those thresholds fall.
Cammihouse produces twelve capsule house models across the A, C, H, R, P, and Z series. Each is factory-built and engineered around a defined occupancy scenario — from solo compact stays to four-person residential use. Floor areas run from 15.70 ㎡ (A3) up to 38 ㎡ (A7). Rather than pushing buyers toward the largest model available, Cammihouse structures its range so that each unit matches a specific set of real-world conditions. Three models illustrate the most common purchase decisions.
The A3 measures 5,600 × 2,800 × 3,100 mm with a 15.70 ㎡ interior rated for two occupants. A shower room and toilet are built into the footprint, so no external bathroom block is required. At roughly 5 tonnes, it ships on a standard flatbed and can be set in place without heavy crane equipment on most residential or commercial plots. Buyers using the A3 include solo remote workers, couples running a backyard prefab house as a home office, and property owners adding a self-contained rental unit to an existing lot.
The P5 extends usable area to 31.40 ㎡ at 9,500 × 3,300 × 3,200 mm. Its layout separates the sleeping zone from the living and washing areas, and a wardrobe is included — details that matter when the unit is used full-time rather than on weekends. At 7 tonnes, it requires slightly firmer site preparation but remains within standard flatbed delivery. The P5 is a common choice among remote workers on extended contracts, couples using a small prefab house as a primary residence, and operators building short-term rental clusters in tourist locations.
The A7 runs 11,500 × 3,300 × 3,300 mm with a 38 ㎡ floor plan rated for two to four occupants. It includes a kitchen area, shower room, and open living space — a layout that functions as a genuine residential unit rather than a temporary shelter. Installed weight reaches approximately 9 tonnes with floor heating. Families using a prefab house as a primary home and rental operators building vacation pod clusters consistently choose this format. Its length requires pre-delivery route assessment for access roads narrower than 4 metres.
A unit's dimensions are irrelevant if the site cannot receive it. The A3 and P5 pass through standard 3.5-metre access roads without issue. The A7 at 11.5 metres may need a pre-delivery route survey. Ground conditions determine foundation type — soft or uneven ground requires a concrete pad or adjustable leveling feet. Local permit rules on maximum structure size and boundary setback distances should be confirmed before selecting a prefab house model, as these vary significantly by jurisdiction and sometimes by zone within a single city.
The A3 draws 6.7–11.2 KW at peak load; the A7 draws 9.9–15.4 KW. A 50% increase in floor area brings roughly 37% more peak power demand — not a 1:1 relationship. Buyers who oversize their capsule house for occasional or seasonal use pay a disproportionate energy cost year-round. Matching unit size to actual, regular occupancy — not to a best-case scenario — keeps both purchase cost and monthly running costs in proportion.
Many buyers choose a larger prefab house to accommodate visitors who arrive three or four times a year. The result is a unit that is oversized for 350 days of use and costs more in transport, foundation work, and energy annually. A second, smaller unit added later when guest frequency genuinely increases is a more cost-efficient strategy. Building for confirmed, regular occupancy — not for hypothetical scenarios — is the consistent lesson from buyers who have gone through one sizing change already.
Ask three questions before contacting any supplier. First: how many people will use this space on a regular basis — not occasionally? Second: will this be a primary residence or part-time accommodation? Third: what is the maximum unit length the delivery route can handle? Answering these honestly eliminates most of the Cammihouse range and points to one or two models. The A3, P5, and A7 each represent a distinct answer to this framework, covering the majority of buyers of a modern prefab house worldwide.
FAQ
Q: What is the minimum size prefab house that works for full-time living?
A: For one person living full-time, 20–25 ㎡ covers sleeping, cooking, and washing without significant trade-offs. For two people, 30 ㎡ or above becomes the practical threshold for daily comfort. The Cammihouse P5 at 31.40 ㎡ is specifically designed for two-person full-time occupancy, with separated zones and built-in storage that single-room layouts cannot provide.
Q: Can a small capsule house like the A3 function as a short-term rental?
A: Yes. The A3 is fully self-contained with a bathroom and is rated for two people, making it viable as a rental unit. Operators using Cammihouse capsules as individual pods in glamping or eco-resort settings report strong booking rates. Its compact footprint also means more units fit on a given plot, improving revenue per square metre of land compared to larger single-unit builds.
Q: How does the size of a prefab house affect delivery and installation time?
A: Factory production timelines are similar across models — typically 4–8 weeks. On-site installation varies more: an A3 can be placed and utility-connected in one to two days, while an A7 requires three to five days depending on foundation type. Site preparation should always be completed before the unit arrives; this is where most delays occur, not in the unit itself.
