We've worked on a lot of housing system migrations. Some of them have been brilliant — on time, on budget, with teams that came out the other side genuinely proud of what they delivered. Others have been the kind of projects you think about at 2am.
What's striking is that the ones that go wrong rarely fail for surprising reasons. They fail for the same reasons, over and over again — and almost all of them were visible months before anyone wanted to admit there was a problem.
This post is about those reasons. Not the theoretical ones you'll read in a project management textbook, but the ones we've actually encountered — sitting in project meetings, knee-deep in legacy data, watching a go-live date slip for the third time.
If you're a Housing Association or Local Authority about to embark on a system migration, read this before you start. If you're already mid-project and something feels off, read it anyway.
1. The organisation isn't ready for the change
This one is uncomfortable to say, but it's probably the single most common reason migrations struggle: the technology is the least complicated part of the problem.
A housing system migration isn't just an IT project. It touches every team in the organisation — housing officers, income management, repairs, asset management, finance. It changes how people do their jobs, often fundamentally. And if the organisation hasn't genuinely committed to that change — not just at senior leadership level, but at every level of the business — the project will face resistance that no amount of technical expertise can overcome.
We've seen migrations where the business case was solid, the vendor was capable, the budget was adequate — and it still ran into serious trouble because middle management hadn't bought in, front-line staff hadn't been prepared, and nobody had done the hard work of helping people understand why this was happening and what it meant for them.
Change management isn't a workstream you bolt onto a project plan. It's the foundation the whole thing sits on. If your organisation isn't ready to be honest about what's changing and why, sort that out before you go anywhere near a new system.
2. The data in your legacy system is in a worse state than anyone wants to admit
Here's a conversation we have regularly, usually a few months into a project:
"So what does the data look like in the current system?"
"It's fine. It's been in use for fifteen years, but it's fine."
It is never fine.
Legacy housing management systems accumulate data problems the way old buildings accumulate damp — slowly, invisibly, until it's suddenly everywhere. Duplicate records. Inconsistent property references. Fields that were used for one purpose ten years ago and something completely different since. Free-text fields where structured data should live. Data that was migrated in from a previous legacy system and was already questionable then.
None of this means migration is impossible. But it does mean you need to go in with your eyes open. A proper data audit — before you agree timelines, before you commit to a go-live date — is not optional. It is the work that everything else depends on.
We've seen projects lose months because data quality issues were discovered mid-migration that should have been identified at the outset. Budget the time. Do the audit. Be honest about what you find.
3. Nobody on the client side has enough time to actually do this
This might be the hardest thing to say to a client, but we say it anyway: a housing system migration cannot be led by people who are also doing their full-time jobs.
We understand the pressure. Housing associations and local authorities don't have spare capacity. The people who know the systems, the data, and the business processes best are the people who are busiest. Pulling them onto a project feels costly.
But the alternative is worse. When a migration is led by people who can only give it half their attention, decisions get delayed, testing gets cut short, documentation doesn't get done, and the vendor — or the consultancy — ends up making calls that should have been made by the business. That creates problems that don't surface until go-live, and by then they're expensive.
The organisations that navigate migrations successfully almost always have the same thing in common: dedicated resource. A programme manager who owns it. A business analyst who knows the current system inside out. Subject matter experts who can be pulled in when needed and are actually available when you call.
If you can't resource the project properly, seriously consider whether the timing is right.
4. Nobody has properly thought through what 'the data' actually means
This is the area where we see the most confusion — and some of the most avoidable problems.
When people talk about data migration in a housing system project, they tend to think of it as a single thing: get the data from the old system into the new one. But it's not a single thing. It's at least three distinct and very different problems, and conflating them is a fast route to expensive mistakes.
Retention archiving is about satisfying your legal and regulatory obligations. Certain data has to be retained for defined periods, regardless of whether it's operationally useful. This is a compliance requirement, not a business one — and it needs to be handled accordingly, usually through a dedicated archive solution that meets the relevant standards.
Data and document access is about making sure your staff can still get to historical information — tenancy records, correspondence, repair histories, documents — when they need it. This doesn't necessarily mean bringing everything across into the new system. It might mean maintaining access to a read-only version of the old system, or implementing an archive with proper search capability. The question to answer here is: what do your teams actually need to be able to look up, and how often?
Active migration is what most people mean when they say 'data migration' — the records, transactions, and relationships that the new system needs to function on day one. This should be the smallest of the three datasets, not the largest. A common and costly mistake is trying to bring across everything, including historical data that nobody will ever use, simply because nobody has asked the question of what actually needs to move.
These three things have different owners, different timelines, different technical requirements, and different risk profiles. Treating them as one workstream is one of the most common and consequential mistakes we see on housing system projects.
So what does good look like?
The migrations that go well share a handful of characteristics that are worth naming directly.
They start with honesty — about the state of the data, about the organisation's readiness, about what's achievable in the timeframe. They have dedicated, empowered resource on the client side. They invest in understanding what 'done' actually looks like before they start building. And they treat data — all of it, in its different forms — as a problem that deserves its own structured thinking, not an afterthought.
They also, in our experience, tend to have independent technical support alongside the vendor. Not because vendors are incompetent — many are excellent — but because the vendor's incentives and the client's interests aren't always perfectly aligned. Having people in the room who are accountable only to the client, and who understand both the technical landscape and the housing sector, makes a material difference.
A final thought
If you're about to embark on a housing system migration and anything in this post has rung a bell, that's worth taking seriously. These problems are fixable — but they're much easier to fix before a project starts than during one.
We're not in the business of scaremongering. We've been part of migrations that have gone really well, and we know what the difference looks like. If you'd like to talk through where your project stands — whether you're in planning, mid-delivery, or trying to work out what went wrong — we're happy to have that conversation.
Ryan Tirrell is the Founder and Director at RTBSS, a technical consultancy specialising in housing system implementations for Housing Associations and Local Authorities across the UK.