Container house in the Philippines: the permit, the heat and the ceiling height

A container house is built from shipping containers: steel boxes made to carry cargo, cut open, insulated and fitted out as rooms. They are popular in the Philippines as a quick first home, a rest house on family land or a small rental unit, and most search results are suppliers selling them. This guide covers the questions a supplier’s page tends to skip: the permit, what the building code asks of the rooms, and what the climate does to a steel box. Our custom house design service designs container and small houses to those rules.

Do I need a building permit for a container house?

Yes, if it is a home. The National Building Code (PD 1096), Section 301, says no one may erect, construct, alter, repair, move, convert or demolish a building without first obtaining a building permit from the Building Official. The decree’s only exception is for traditional indigenous family dwellings (Section 103(a)). It makes none for steel, for factory-made buildings or for small ones. A container set on a foundation, connected to water and power, and lived in is a building.

The application is the same as for any house: the plans, signed by the professionals the rules name, plus the lot documents. The building permit requirements guide lists them, and our permit and documentation assistance service prepares and files them. A container left on a lot as storage raises questions the decree does not answer directly, so ask your building official before you buy if you are unsure.

The ceiling height is the hard part

Containers come in two common heights. Measured inside, a standard container is usually about 2.39 m tall and a high-cube about 2.69 m. Those are typical figures, so measure the one you are offered.

The building code asks for a ceiling of 2.70 m in a habitable room with natural ventilation, or 2.40 m where artificial ventilation meets Section 811 (PD 1096 Section 805). Insulation and a finished floor take some of the inside height. So:

• A standard container falls short of even the 2.40 m figure once it is insulated.
• A high-cube can reach about 2.40 m after a thin floor and ceiling, which means its rooms rely on mechanical ventilation to meet the code.
• Neither reaches 2.70 m for rooms cooled by open windows alone.

That is why many container designs stack or join boxes with parts of the roof or floor removed, or use the containers for bathrooms and storage and build the living room another way. The room size checker tests a room against these figures.

The width and the air space

The other room rules are easier. Section 806 asks for 6.00 m² and a narrowest side of 2.00 m for a room people live in, 3.00 m² and 1.50 m for a kitchen, and 1.20 m² and 0.90 m for a bath and toilet. A container is roughly 2.35 m wide inside, so a room the full width passes, though it feels narrow.

Section 807 asks for 14.00 m³ of air for each person in a habitable room. A 20-foot container, about 2.35 m by 5.9 m inside, has roughly 13.9 m² of floor. At 2.40 m that is about 33 m³, enough for two people if the whole box is one room. Divide it into a bedroom and a toilet and the bedroom alone has to be checked again.

Heat: a steel box in the Philippine sun

Steel takes in heat fast and passes it through. An unshaded container in the afternoon sun becomes very hot inside, and air conditioning alone fights a losing battle. What works:

• A separate roof above the box, on its own frame, with a ventilated gap so the sun hits the roof and not the steel. Deep overhangs on this roof shade the walls too.
• Insulation on every side, including the floor if the box is raised. Insulation outside the steel keeps the steel itself cooler; insulation inside is simpler but leaves the steel to heat up.
• Openings on opposite walls so air crosses the room. Section 808 asks for windows of at least a tenth of the floor area where there is no artificial ventilation.
• Shade from trees or the house next door on the west side, where the afternoon sun is strongest.

The climate guide explains shading and cross-ventilation in more detail.

Damp, rust and rain

• Condensation. When cool air-conditioned air meets warm steel, water forms on the inside of the wall. Insulation with a proper vapour barrier, sealed at the joints, stops it.
• Rust. Salt air near the coast attacks steel. A container near the sea needs a marine-grade coating, kept up, and its roof drained so water does not sit on it.
• Rain noise. Rain on bare steel is loud. The separate roof and the insulation take care of most of it.

Cutting openings and holding it down

The corrugated walls are part of what makes a container strong. Every large opening for a window or a door takes some of that strength away, and joining two boxes side by side often removes a whole wall. A structural engineer should design the steel frames around the openings, and the plan for how the boxes connect.

A container also has to stay put in a typhoon. The building code asks every dwelling for footings at least 250 mm thick and 600 mm below the ground, and roofs designed for at least 120 kg/m² of wind (PD 1096 Section 708). Containers set loose on blocks do not meet that: they need a foundation and a fixing the engineer designs. Raising the box on piers keeps it out of floodwater and lets air under the floor; the elevated house design guide covers how high.

Used or new

A used container has carried cargo for years. Ask what it carried and what its floor was treated with, since cargo container floors are often treated timber. Check for rust holes, dents in the corners and roof, and doors that still seal. A new, one-trip container costs more and avoids most of those questions.

What the supplier does not do

A supplier sells and fits out the box. Most of what makes it a legal, comfortable home happens on your lot and is still your job:

• the foundation and anchoring
• the toilet’s waste: on most lots outside a sewer area, a septic tank, which the septic tank guide covers
• water, power and drainage connections
• placing the house within the lot coverage and setbacks of Section 708(a), which the lot coverage calculator checks
• the building permit, and later the occupancy permit

Ask the supplier which of these they include, in writing, before you pay.

Is a container house a good idea?

It can be, for the right use. It suits a small unit where speed matters and the design accepts the box’s width and height. It suits a family home less well, because the code’s ceiling heights and the heat both push against it. The tiny house design guide covers other ways to build small, and the prefab house guide covers factory-built houses that are not containers.

Designing your container house

Our custom house design service plans a container house to the code: the ceiling heights, the openings, the roof that keeps it cool and the foundation that holds it down. We then prepare the drawings for the permit.