Access Control for Multi-Tenancy Buildings: Where Shared Entries Go Wrong

Single-tenancy access control is a solved problem. One organisation, one set of rules, one person who decides who gets in.

Multi-tenancy is different, and the difficulty is rarely technical. It is that several organisations share a front door, a lift, a car park and a bin room, and none of them has authority over the others’ staff.

The short answer

A multi-tenancy building needs access rules drawn around three distinct zones: shared areas everyone uses, tenancy areas each organisation controls, and restricted areas almost nobody should reach. Most buildings get the first two roughly right and the third badly wrong.

The restricted zone is where the real exposure sits. Comms rooms, key cabinets, plant rooms, roof access and storage cages are the areas that give someone control over everything else in the building, and they are routinely secured with a mechanical key that twelve people have copies of.

Why shared buildings drift out of control

Four things happen to every multi-tenancy building over time.

Tenants change, credentials do not. A business moves out. Its twenty fobs go with it. Nobody deactivates them because nobody owns that process.

Keys multiply quietly. A mechanical key can be copied at a shopping centre kiosk. There is no record, no expiry and no way to know it happened.

Contractors accumulate access. Cleaners, lift technicians, fire services, plumbers and the coffee machine company all need to get in. Each arrangement is made separately, often informally, often years ago.

Doors get propped. Every building has one door that is inconvenient, and it stays open with a fire extinguisher under it from 6am.

None of these is a failure of the hardware. They are failures of the administrative layer around it, which is why replacing readers rarely fixes a building that has drifted.

The three zones, and what each needs

Shared areas

Main entries, lifts, lobbies, loading areas, bin rooms and shared amenities.

What they need: credentials that can be issued and revoked centrally, time-based rules that differ between business hours and after hours, and a record of who entered.

The common mistake is treating shared areas as low risk because everyone uses them. Shared areas are where an unauthorised person becomes an ordinary-looking person, and after that nobody questions them.

Tenancy areas

Each organisation’s own floor or suite.

What they need: independent control, so a tenant can add and remove its own staff without going through the building manager for every change. Tenants will route around a system that makes them wait three days to give a new employee a fob.

Restricted areas

Comms and server rooms, key cabinets, plant and switchboards, roof access, storage cages.

What they need: electronic access with an audit trail, a small named list, and a review schedule. These doors are the ones worth spending money on, and they are usually the ones left on a mechanical key.

On the Longview Victorian headquarters project, a multi-tenancy building with basement parking, a dedicated office level and shared areas, the key room was treated as its own protected zone rather than as a cupboard. TVT CCTV, an Elite alarm system and Akuvox access control were brought together so that one system governed the building rather than three that each knew part of the story. The published case study records the site as supporting around 85 staff. The detail is in the Longview case study.

Basement car parks deserve their own section

The basement is consistently the weakest point in a multi-tenancy building, for structural reasons rather than negligence.

It usually has a vehicle entry governed by a roller door or boom gate, which stays open long enough for a second vehicle or a pedestrian to follow. It is poorly lit relative to the rest of the building. It frequently contains storage cages. And it is the one area where a person can spend ten minutes without anyone finding that unusual.

Thefts from Victorian apartment car parks and storage cages are covered in detail in the basement is the breach. The commercial equivalent is less publicised but structurally identical, because the weaknesses are architectural rather than residential.

Three things help, in order of effect: controlling pedestrian access separately from vehicle access, cameras positioned to identify rather than merely observe at the entry, and door open too long monitoring on the pedestrian doors between the car park and the building.

Credentials: what to actually choose

Credential	Strength	Weakness	Reasonable use
Mechanical key	No power, no failure	Copied freely, no audit trail, no revocation	Last resort and override only
Proximity fob	Cheap, familiar	Clonable, lost frequently	Shared areas, low-risk doors
Smart card	Harder to clone	Costs more, needs management	Tenancy and shared areas
Mobile credential	Issued and revoked instantly, hard to lend casually	Depends on phones and connectivity	Staff access, contractors
PIN	No hardware to lose	Shared verbally, rarely changed	Secondary factor, not primary
Biometric	Hard to transfer	Privacy obligations, cost, failure rate	Restricted zones only

The practical answer for most Melbourne buildings is mobile credentials or smart cards for people, mechanical override for emergencies, and electronic access with an audit trail on restricted doors.

The administrative layer, which is the actual product

Hardware is the easy part. The part that decides whether a building stays secure in three years is the process around it.

A workable arrangement answers these questions in writing:

• Who issues credentials, and who approves the request?
• How quickly is access revoked when someone leaves, and who triggers it?
• Who reviews the restricted-area list, and how often?
• What is the contractor process, and does it expire automatically?
• Who holds the master override, and where is it kept?
• Who checks the audit trail, and when?

If a building cannot answer these, better hardware will buy perhaps eighteen months before the same drift resumes.

Common mistakes

Designing around the building rather than the organisations in it. The floor plan is not the access model. The tenancy agreements and the staff movements are.

Giving the building manager every permission. Convenient, and a single point of compromise.

Treating the comms room as a utility space. Someone with access to your network cabinet has access to considerably more than a room.

No door open too long alerting. Propped doors defeat the entire system and are invisible without it.

Buying a system a tenant cannot administer. If adding a staff member requires an email to someone else, tenants will hand out spare fobs instead.

What to do next

Walk the building once with this list:

1. Count the doors between the street and the most sensitive room. If the answer is two, that is the problem.
2. Identify every mechanical key in use and ask how many copies exist. Nobody will know, which is the answer.
3. Ask each tenant how they add a new staff member, and time it.
4. Check whether the car park pedestrian door is on the same credential as the main entry.
5. Look at the audit trail for the comms room for the last ninety days. If there is no audit trail, start there.

Frequently asked questions

Can tenants manage their own access without the building manager? Yes, with a system that supports delegated administration. Each tenant controls its own area while the building manager retains shared areas. This is usually the difference between a system that is used and one that is routed around.

Do we have to replace all the door hardware? Not necessarily. Existing locks, strikes and door controllers can sometimes be retained and brought onto a new controller. A site inspection establishes what is reusable.

How long should access records be kept? Long enough to be useful for an investigation and no longer than you can justify. Access records are personal information, so retention should be deliberate rather than indefinite. The documentation obligations around this are covered in AI cameras and the 2026 privacy rules.

What happens in a power failure or a fire? Door hardware must fail in the mode that building regulations and the fire strategy require, which is not always the mode that is most secure. This is a design decision, not a product decision, and it needs to be made explicitly.

Can access control integrate with the alarm and cameras? Yes, and it should. The value of integration is that a single event (a door forced at 2am) produces an alarm, a camera view and an access record together rather than three unrelated records.

Where to start

Multi-tenancy access control fails administratively before it fails technically. The buildings that stay secure are the ones where somebody owns the process, and the system was designed to make that ownership easy.

Forever Secure designs access control around how a building is actually used rather than how the floor plan looks, and brings CCTV, alarms and access onto one platform so an incident produces one story instead of three. The on-site assessment is free, and the written findings are yours either way.

Book a free on-site security assessment or call 1300 232 152.