Stand in front of any post-war social housing estate and you can read its biography in the fabric. The flat roofs patched over and over like layers of geological time. The spalled concrete revealing the rebar beneath. The single-aspect flats where residents crack windows year-round just to fight condensation. The service voids you can't reach without ripping out someone's kitchen.

None of this is accidental. This isn't entropy or bad luck or inadequate maintenance budgets, though those things matter.

This is design. And design has a remarkably long tail.

The homes we rushed, the ones we experimented with, the ones we value-engineered to meet political deadlines or budget constraints—these are now the homes consuming billions in maintenance, demanding impossible retrofit interventions, and generating the complaints that dominate Housing Ombudsman reports.

We're not just managing an aging stock problem. We're managing the consequences of design decisions that were flawed from the moment the drawings were approved.

And here's the uncomfortable truth: we're still making those same mistakes.

The Ghost of System-Build Past

Following the Second World War, there was a need for a great deal of new housing, and new construction techniques were adopted, in particular by local authorities and other public bodies. Speed was everything. Innovation was encouraged. The housing crisis was real and urgent, and we responded with prefabrication, system-build, and experimental materials.

Some of these systems proved robust. Others deteriorated prematurely. Prefabricated construction techniques in particular resulted in a large number of defects, eventually requiring formal designation under the Housing Defects Act 1984.

But the real legacy isn't just the designated defects, it's the design philosophy they represented: optimise for speed of delivery, not longevity of performance.

Walk through a 1960s tower block and you'll see it everywhere. Services buried in concrete where you can't reach them. Thermal bridges designed into every junction. Single-glazed metal windows that were never going to cope with British winters. Flat roofs that defied the basic physics of water drainage.

The people who designed these buildings weren't incompetent. They were responding to the incentives in front of them: build fast, build cheap, solve the immediate crisis. Long-term maintainability wasn't on the brief. Resident experience wasn't part of the specification. Energy performance wasn't a consideration because energy was cheap.

The Data Confirms What We Already Know

The Regulator of Social Housing's 2025 reports make uncomfortable reading. Despite decades of investment, many landlords still lack a reliable, complete understanding of their stock condition. Not because they're negligent, but because the buildings themselves resist documentation.

How do you survey a system-built block where key junctions are hidden behind cladding? Where building drawings don't match what was actually built? Where multiple retrofit interventions have layered complexity upon complexity?

The answer is: destructively, expensively, and incompletely.

Meanwhile, BRE's analysis estimates £1.4 billion per year in first-year NHS treatment costs attributable to poor housing hazards in England, with wider societal costs reaching £18.5 billion annually. These aren't just numbers, they represent real people living with damp, cold, and hazards that were designed into their homes from day one.

The Housing Ombudsman reports a surge in complaints about housing conditions since 2019/20, with leaks, damp, and mould dominating. That's not a sudden deterioration in maintenance standards. That's the built-in failure modes of poorly designed housing finally overwhelming the ability of repairs teams to keep patching them.

The Modern Repeat: When History Doesn't Teach

You'd think we'd have learned. But walk through a newly completed social housing scheme and you'll see echoes of the same thinking.

We're building tight thermal envelopes without properly considering how residents will actually ventilate their homes. We're installing complex mechanical ventilation with heat recovery (MVHR) systems that require regular filter changes and specialist maintenance, in properties where residents might not understand what MVHR even is.

We're fitting heat pumps optimised for low flow temperatures, then connecting them to radiator systems sized for gas boilers. We're creating "smart homes" with control interfaces that require three button presses to adjust the heating, in properties occupied by elderly residents who just want their home warm.

As of 31st March 2025, PAS 2035:2023 became the required standard for all retrofit projects, specifically because we kept repeating these mistakes. The standard now mandates whole-dwelling, risk-managed approaches precisely to prevent the moisture and ventilation failures we've seen time and again.

The updated standard exists because we kept optimising individual components without understanding the system they were part of.

But here's the problem: PAS 2035 only applies to funded retrofit work. New build and non-funded improvement projects can still make the same mistakes, just with newer materials.

The Usability Crisis Nobody Discusses

There's a pattern in user studies of low-carbon housing that should terrify the sector: performance drops dramatically when residents don't understand or can't operate the systems we've installed.

That "efficient" heating system? It's inefficient in practice if residents override the controls because they're too complex. That MVHR unit providing balanced ventilation? It's useless if filters aren't changed and residents open windows because they don't trust the system.

This isn't a resident problem. This is a design problem.

We've created homes that require an engineering degree to operate optimally. We've installed systems that assume perfect maintenance behaviour. We've designed for theoretical performance rather than lived reality.

And then we act surprised when residents complain, when performance doesn't match predictions, when complaints about comfort and condensation pile up.

The Hidden Economics of Bad Design

Here's what poorly designed homes actually cost:

Retrofit impossibility: Try retrofitting solid wall insulation on a building with chronic interstitial condensation issues. Try improving airtightness in a dwelling with inadequate ventilation. Try installing a heat pump in a property with undersized distribution systems. These aren't technical challenges—they're design legacies that make improvement prohibitively expensive.

Resident churn and dissatisfaction: People leave homes they can't live in comfortably. High turnover costs money in voids, re-lets, and lost rental income. But it's also a signal that the home itself is failing to meet basic human needs.

Regulatory exposure: Awaab's Law timelines, the new Safety and Quality Standard, and the tightening enforcement regime all assume you can actually fix problems within prescribed timeframes. But what if the problem is the building's fundamental design? What if compliance would require ripping out major structural elements?

Why We Keep Building Tomorrow's Backlogs

The sector optimises for the wrong metrics. We celebrate:

• Delivery speed: How many units completed this quarter?

• EPC ratings: What theoretical energy performance do we achieve?

• Capital cost: What's the lowest price we can build for?

We rarely ask:

• Maintainability: Can you actually reach and replace key components?

• Moisture safety: Will this junction accumulate interstitial condensation over time?

• User operability: Can a typical resident operate this system intuitively?

• Whole-life cost: What will this actually cost to maintain over 30 years?

Design briefs and employer's requirements rarely include "repairability" as a core criterion. Planning approvals don't consider long-term maintenance burden. Value engineering exercises cut the things that make buildings work well over time, because those benefits won't show up for years.

We're commissioning tomorrow's backlogs because we're not scoring for the right outcomes.

_{Articles to Dwell On}