What People Overlook About GRP Enclosures in Industrial Builds

GRP (Glass Reinforced Plastic) enclosures are commonly used across utilities, energy, and industrial infrastructure projects. At Hill Grwp, we’ve engineered and delivered GRP housing solutions across critical infrastructure sectors, including water and wastewater, power distribution, energy, and industrial utilities. Our enclosures are trusted for applications such as pump stations, electrical switchgear and control panels, and metering systems where durability, compliance, and rapid deployment are essential 

Yet, despite their wide use, GRP enclosures are still misunderstood or undervalued—especially in terms of how they compare to more traditional materials like timber or concrete. 

Here are some insights we’ve gathered from working with GRP housings on a day-to-day basis: 

Industrial GRP Enclosure ready for delivery

1. Not all GRP is built the same 

GRP is often seen as lightweight or temporary, but that only applies to low-grade options. A properly engineered enclosure—with multi-skin wall construction, structural reinforcement, and

high-spec laminate thickness—can outperform timber in both longevity and insulation. 

Ventilation grill mounted on a GRP building, designed to enhance airflow.

2. Ventilation and cable access are critical 

A frequent issue we see on-site is insufficient design planning for gland plates and airflow. These details may seem minor, but inadequate provision for cable entry or ventilation can cause commissioning delays, require costly rework, and impact long-term equipment performance. Integrating these requirements at the design stage ensures a smoother installation and reduces lifecycle risk.

3. Fire and security compliance matters more than people think 

GRP can be manufactured to meet stringent standards such as LPCB certification and BS 476: Part 20 and Class O fire ratings. In many regulated industries (water, power, oil & gas), these certifications are not optional—they’re essential. Always confirm the enclosure spec aligns with compliance requirements from the outset. 

Galvanised steel base securely mounted to the Hill Grwp GRP building, showcasing robust construction and durability.

4. Foundations require coordination 

Many of our GRP housings are delivered pre-mounted to a galvanised steel base or ready to bolt down to concrete skid. While this speeds up on-site installation, it only works if the civils team is aligned early. A mismatch in slab layout or bolt configuration can cause delays. 

GRP housings have evolved significantly—and when designed well, they offer excellent durability, protection, and installation speed. If you’re comparing GRP to timber kiosks, concrete chambers, or in-situ builds, feel free to reach out to our team for more insight.