PUF vs Aerocon vs LGS: choosing a building system

• —PUF sandwich panels: a polyurethane foam core bonded between pre-coated steel skins. Light, rigid and highly insulating. Used for cabins, cold rooms, clean rooms and E-House enclosures.
• —Aerocon panels: a lightweight cement-based core faced with fibre-cement boards. Heavier and more solid than PUF, with a masonry feel. Used for classrooms, clinics, canteens and accommodation.
• —LGS (light gauge steel): cold-formed galvanised steel sections, cut and assembled into a structural skeleton of walls, floors and roof trusses. It is the frame, not the finish — and it needs an infill or cladding.

So the real question is usually twofold: what carries the building, and what forms its walls? A small cabin may be a steel frame with PUF panels. A villa may be an LGS frame with Aerocon or cement-board infill. A cold store may be PUF almost end to end.

PUF is the thermal specialist. A thin panel keeps heat out far better than a much thicker masonry wall, which is why cold rooms and air-conditioned cabins use it. The trade-off is low mass: a PUF room heats up or cools down quickly when the air conditioning is switched off.

Aerocon offers moderate insulation with more thermal mass, so indoor temperatures move more slowly. People often describe an Aerocon building as feeling like a normal building, which is exactly the point. With LGS, comfort comes from what fills the frame — the wall build-up can be tuned with insulation in the cavity and boards on each face.

Cement-based panels such as Aerocon are non-combustible, which gives a meaningful margin of safety for classrooms, clinics and accommodation. PUF panels are available with different core formulations, and the right one depends on the use; your project's fire consultant or authority will tell you what the building must achieve, and that should be written into the specification.

For sound, mass and separation help. Aerocon walls are naturally quieter. LGS walls with insulated cavities and double boards can be very quiet too. PUF cabins are fine for offices but benefit from acoustic ceilings or linings where people meet or sleep.

All three are dry systems, which is their shared advantage over brick and concrete. There is little or no curing time, little water on site and far less waste. The work that remains on site is assembly: fixing panels, joining frames, sealing joints and finishing.

Weight shapes the foundations and the logistics. PUF panels are the lightest, so PUF cabins travel easily and sit on simple pedestals. LGS frames are light for their strength, which keeps foundation loads down even for two- or three-storey buildings. Aerocon panels are heavier and more robust, closer to masonry in how they handle and feel, but still far lighter than a block wall of similar performance.

Finish also affects programme. PUF panels arrive pre-coated and need no painting. Aerocon walls are usually jointed, puttied and painted, or tiled, which adds a short finishing stage. LGS buildings take whatever finish the design calls for, from simple paint to stone cladding, and the programme follows.

• —PUF: pre-coated steel skins resist weather well; keep joints sealed and repair any dents or scratches that expose the steel, especially near the coast.
• —Aerocon: cement-based faces resist rot, termites and moisture; repaint as you would a plastered wall and keep the base above splash level.
• —LGS: galvanised members resist corrosion inside a well-sealed envelope; the priority is keeping water out through good roofing, flashing and detailing.

• —LGS frame + Aerocon infill: solid, quiet walls on a light, fast frame. Good for schools, accommodation and homes.
• —LGS frame + PUF panels: a light, well-insulated envelope, suited to offices and cooled spaces.
• —LGS frame + cement board and insulation: the most flexible build-up for villas and resorts, taking plaster, tile, timber or stone cladding.
• —Steel frame + PUF panels: the classic portable cabin and E-House enclosure.
• —PUF roof over Aerocon walls: a common way to combine solid walls with a well-insulated roof.

Start with how long the building must last and how it will be used. If it must be cool, light and relocatable, lean to PUF. If it must feel permanent and quiet with little site work, lean to Aerocon. If it must be multi-storey, architecturally shaped or long-lived, start with an LGS frame and choose the infill to suit.

Send us the use, the size and how permanent it needs to be, and we can propose a build-up and explain the reasoning.