Choosing the Right Fire Alarm System: Open vs Closed Protocol
If you’ve recently been quoted for a new fire alarm installation, you may have noticed technical terms like “open protocol” and “closed protocol” in the proposal.
At first glance, it sounds like industry jargon — but understanding the difference is important. The system you choose will affect how easily your alarm can be maintained, who can service it, and what it will cost over time.
At Fletcher Risk, we don’t sell fire alarm systems — we help clients make informed decisions about them. Here’s a straightforward guide to what these terms mean and what you should think about before signing off on a new installation.
🔒 What is a Closed Protocol Fire Alarm System?
A closed protocol system uses hardware and software that are proprietary to one manufacturer. The control panel and detectors “speak” a private language, meaning only equipment and software from that manufacturer will work with the system.
In practice, this means you’ll usually need to use the same company (or one of its approved partners) for maintenance, testing, and future upgrades. Replacement parts have to be ordered from the manufacturer, and any programming or fault diagnosis requires special software that only they can access.
The advantages: closed systems are often extremely reliable because all components are designed to work perfectly together. They may also offer advanced networking and monitoring features that appeal to large or complex sites.
The disadvantages: you’re tied to one supplier for the lifetime of the system. Servicing costs may be higher, competition is limited, and future upgrades must use compatible parts — even if cheaper alternatives exist elsewhere.
🔓 What is an Open Protocol Fire Alarm System?
An open protocol system uses standard communication technology that allows different manufacturers’ components to work together.
For example, an open-protocol panel might operate detectors and call points made by several reputable suppliers, as long as they all follow the same technical standard.
This flexibility means you can choose from multiple service providers, source parts from a wider range of suppliers, and expand or modify the system more easily in future.
The advantages: you have more freedom to select who maintains the system, prices tend to be more competitive, and spare parts are easier to obtain.
The disadvantages: because the system can combine products from different brands, integration quality depends on how well those components are designed to work together. Some manufacturers may also provide less direct technical support when multiple products are involved.
🧭 Which is right for you?
There’s no single “best” choice — it depends on your building, your budget, and how much control you want over maintenance in the long term.
Open protocol systems are usually the most practical option for small to medium-sized premises such as offices, retail units, and multi-tenant buildings. They give you flexibility, independence, and the freedom to switch maintenance providers without being locked into one brand.
Closed protocol systems are better suited to large or complex environments where close integration and manufacturer support are critical — for example, hospitals, industrial facilities, or sites with centralised monitoring. Because every component comes from one supplier, reliability is high, but you’ll rely on that same company for all servicing and future modifications.
In simple terms:
If you value flexibility, independence and cost control, an open protocol system is likely the better fit.
If your site demands advanced integration and one-to-one manufacturer support, a closed protocol system may suit you better.
🧩 Think about ownership and independence
One of the biggest frustrations we see is when a building owner wants to change maintenance companies but can’t — because their system is locked down with manufacturer passwords and proprietary software.
If your system is closed-protocol, you may have to stay with the same supplier indefinitely, even if service quality or pricing changes.
Before you agree to a new installation, ask your installer:
Is the system open or closed protocol?
Can other qualified engineers maintain it if we change provider?
Will we own the programming codes and access software?
Are replacement parts freely available from multiple sources?
Getting clear answers now can save major costs and headaches later.
🧠 Compliance and long-term responsibility
From a legal point of view, both open and closed systems can fully meet UK fire-safety standards — provided they’re designed, installed and maintained to BS 5839.
However, under the Regulatory Reform (Fire Safety) Order 2005, the Responsible Person must ensure that the fire alarm system remains “suitable and sufficient” at all times.
That means it must be serviceable, maintainable and operational throughout the building’s life — another good reason to think about long-term access and support before you buy.
🔧 How Fletcher Risk can help
At Fletcher Risk, we don’t install alarms — we make sure they’re fit for purpose and compliant.
We work with landlords, facilities teams and installers to ensure that the fire-alarm system you choose aligns with your building’s fire-risk assessment and long-term management plan.
Our support includes:
Reviewing specifications before installation.
Checking design and maintenance access support compliance.
Providing impartial advice on open vs closed system implications.
Conducting post-installation audits and integrating alarms with your wider fire-safety strategy.
With independent guidance early in the process, you can select a system that protects people, property and your flexibility for years to come.
🔑 The key takeaway
Both open and closed protocol fire-alarm systems can deliver excellent protection — but they come with different trade-offs.
Open protocol systems give you flexibility and control.
Closed protocol systems give you integration and consistency.
Before you focus on the installation cost, think about who will maintain the system, how easy it will be to expand, and what control you’ll have in five or ten years’ time.
If you’d like independent advice on your fire-alarm quotation or want to check whether your chosen system supports long-term compliance, Fletcher Risk can help.
👉 Contact us for clear, impartial guidance on choosing the right alarm system for your building.
Fletcher Risk Team - 1 November 2025
Disclaimer:
This article is provided for general information only and does not constitute legal or professional advice. While every effort has been made to ensure accuracy, fire-safety requirements may vary depending on your building and local authority. For specific guidance or a formal Fire Risk Assessment, please contact Fletcher Risk or a qualified fire-safety professional.