OT remote access that gives specialist contractors the access they need without losing control
Building systems often depend on multiple specialist contractors. Each contractor may need remote access to its own system, but unmanaged or undocumented access routes create operational and security risk across the OT networks behind your building.
IT4Automation helps landlords and FM providers implement controlled, named and auditable OT remote access for specialist building-system contractors, built on zero trust principles, multi factor authentication and clear access governance.
Modern buildings rely on specialist contractors to support systems such as the BMS, access control, CCTV, lighting, metering and security systems. Each of these operational technology systems needs maintenance, and most of that maintenance now happens through remote access.
Over time, remote access arrangements can become difficult to manage. Common issues include:
Insecure remote access is a major security risk for OT environments. An always-on virtual private network (VPN), an exposed remote desktop protocol (RDP) port or a shared password gives broad network access to anyone who holds it. On flat OT networks with little network segmentation, that one connection can allow lateral movement from a single system to the critical systems around it, including legacy systems and legacy protocols that were never designed for external access. Every unmanaged route adds to the attack surface of the building.
IT4Automation helps create a controlled access model that supports operational requirements while improving accountability. It applies zero trust principles to third party access: no contractor is trusted by default, every access request is checked, and granted access is limited to the systems that contractor supports.
The model can include:
Contractors connect through controlled remote access gateways or managed jump servers rather than directly to building systems, and network segmentation keeps each contractor inside its own part of the OT network. The objective is not to block specialist contractors. It is to make remote access safer, clearer and easier to govern.
A controlled contractor access model turns remote access from an unknown into something the property team can see, manage and evidence. For landlords, managing agents and landlord network owners, it helps provide:
Security teams in tenant organisations increasingly ask landlords how third party access to building systems is controlled. A documented, secure remote access process gives you a clear answer, and it sits naturally alongside managed support for your landlord network.
Operational building systems require a practical approach to access control. IT4Automation understands that contractors may need rapid access during incidents and planned maintenance windows. Our approach balances security, accountability and operational need, so strict access controls never stop a contractor fixing a fault.
We help clients define:
Every remote access session then follows the same governed path.
The contractor raises an access request for a named system and a stated reason.
An agreed approver on the property or FM side authorises the request.
The named user signs in with multi factor authentication.
Granular access controls restrict the session to approved OT systems for an agreed time.
Session logging records who connected, to what and when, where the platform allows.
Access and session records are reviewed periodically and after incidents.
Access is removed when the work, the contract or the person changes.
Secure contractor access is mostly delivered through the Connect and Protect foundations, and it leads with Control. Each outcome gives the property team something specific.
See every contractor, account and remote access route into your building systems.
Make sure access is granted on purpose, to the right person, for the right system and time.
Show auditors, tenants and stakeholders that remote access is governed.
Where required, IT4Automation can support enhanced remote maintainer access models, including separately scoped zero trust access solutions such as ZTRAS, our Zero Trust Remote Access Service.
ZTRAS is a zero trust network access (ZTNA) approach to OT remote access. Instead of placing remote users on the network through a traditional VPN, it connects an authenticated user to the specific system they are approved to reach, which helps with limiting lateral movement and reducing the attack surface. These services can provide additional controls for sensitive, regulated or higher-risk environments, including buildings that host critical infrastructure tenants.
ZTRAS is explained in full on our Connect page. You can also watch the ZTRAS animation and listen to our podcast, OT Remote Access: The VPN vs ZTRAS, in Resources.
Controlled contractor access is already part of how IT4Automation supports landlord networks in demanding commercial properties.
A 12-floor building with up to 12 segmented building services on one network. IT4Automation delivered contractor access with named accounts, MFA and logging, and has supported the building for 16 years.
Three managed office buildings across 44 floors with two Critical National Infrastructure tenants, designed to NCSC CAF with MFA contractor access, logging and monitoring, delivered by NPPV3/SC-cleared engineers.
IT4Automation combines IT infrastructure capability with operational technology and building services experience. We support the network, server, firewall and remote access infrastructure that building systems use, while specialist contractors remain responsible for their own applications, controllers and field equipment.
Accreditations: UKAS-accredited ISO 9001, ISO 14001, ISO 45001 and ISO 27001, Cyber Essentials, SafeContractor and Constructionline Gold.
OT remote access is the way engineers and specialist contractors connect to operational technology, such as a BMS, access control or industrial control systems, from outside the site. Secure OT remote access controls who can connect, what they can reach, how long for, and what is recorded.
A zero trust approach is generally the most secure. Each user is named, uses multi factor authentication, is approved for specific systems only and is logged. This is safer than a shared VPN or an exposed remote desktop connection, which can give broad access to the whole network.
A VPN usually places a user on the network, so a compromised account can move between systems. Zero trust network access (ZTNA) connects the user only to the approved application or device, which limits lateral movement and makes each session easier to control and audit.
BMS remote access should use named accounts, an approval step, MFA, access limited to the contractor’s own system, time limits where appropriate, session logging and regular reviews. Access should be removed promptly when contracts or personnel change.
No. IT4Automation supports the infrastructure layer, including networks, servers, monitoring and remote access. Specialist contractors remain responsible for their applications and field equipment, and keep the access they need to maintain them.
If contractor access has grown over time, a one-building OT infrastructure risk review includes a review of current access routes and gives you a clear, prioritised plan.
IT4Automation visited to perform a network survey and assisted with troubleshooting a network issue… I was very pleased with the service that IT4Automation provided and would certainly contact them again in the future if needed.
Stuart Jolley – S,C&I Engineer, Systems Lead
Great communication, reliable and your team… worked pretty much non stop start to finish. I think this upgrade has made a good improvement to the machine and will improve reliability.
George Voisey – Balfour Beatty Rail
If contractor access has grown over time or is not fully documented, IT4Automation can help you review, rationalise and control access to your landlord network.
