HHSRS 2026: Five things landlords should be checking in their properties

The Housing Health and Safety Rating System has changed. In this article, we look at five practical areas private landlords should be paying particular attention to as we head into winter. 

If you're a landlord, you've probably heard of HHSRS. But in June this year, the system received its most significant update since it was introduced in 2006.

That June guidance was then updated again on 16 September 2026 to provide further clarification, making this a particularly good time for landlords to revisit what HHSRS means in practice. 

The principle remains the same: identifying conditions within a home that could pose a risk to the health and wellbeing of its occupants. What has changed is how those risks are categorised and assessed. 

For landlords, though, the important question is much simpler: 

What should I actually be looking for in my properties? 

HHSRS is ultimately a risk-based assessment. It is not simply about whether a property has a defect, but whether that defect could cause harm

1. Damp and mould: look beyond what you can see

One of the most important things landlords can understand is that visible mould is usually the result of an environmental problem, not the beginning of one. 

Mould needs the right conditions to establish: moisture, humidity, temperature, cold surfaces, poor insulation and inadequate ventilation can all play a part. 

Warning signs include condensation, musty smells, staining, cold external walls, water ingress, leaks, damaged gutters, poor insulation and ventilation that is not performing properly. 

Government guidance also points landlords towards factors such as consistently high relative humidity, low wall temperatures, inadequate insulation, poor ventilation and ineffective heating. 

By the time mould becomes visible, the conditions that allowed it to grow may have existed for weeks or months. 

That is why simply cleaning the wall and redecorating is not always enough. 

The better question is not: 

“How do I remove the mould?” 

It is: 

“What is happening in this property that allowed it to develop in the first place?” 

For me, this is the key point: mould is fundamentally an environmental problem. Treat the contamination, but understand and correct the conditions behind it as well. 

2. Ventilation: installed doesn't necessarily mean working

It is easy to walk into a bathroom, see an extractor fan or PIV unit and mentally tick the box marked ventilation. 

But installed does not necessarily mean effective. 

PIV can be useful for supporting airflow and reducing humidity, but it should not be treated as a universal answer to condensation, damp, mould or indoor air-quality problems. 

The wider property has to allow the system to work. Landlords should be asking: 

• Is enough air actually moving through the property? 

• Where is that air entering and leaving? 

• Are door undercuts and internal air paths adequate? 

• Are wet rooms being properly extracted? 

• Is the system correctly sized? 

• Are filters, ducts and vents maintained? 

• Are there cold surfaces or insulation issues that airflow alone will not solve? 

A property can have plenty of airflow and still suffer from mould if surfaces remain cold enough for condensation to form. 

Ventilation cannot compensate for a building that is fundamentally cold, wet or defective. 

There is also an important difference between ventilation and air treatment. 

Ventilation exchanges or dilutes air. It does not automatically remove every mould spore, fine particle, allergen or VOC within that air. 

Outdoor air quality matters too. Homes near traffic or other pollution sources can draw contaminants indoors, so the source and pathway of incoming air matters. 

That is why, in my experience, the answer is rarely simply “more ventilation.” It is about creating a controlled indoor environment. 

3. Excess cold: don't solve one problem by creating another

HHSRS recognises excess cold as a health hazard, but landlords also need to be conscious of excess heat. 

That matters because one of the traditional responses to condensation has been: 

Turn the heating up and increase the ventilation. 

Both may help, but neither is a universal solution. 

A room can feel comfortable while external walls, corners or window reveals remain cold enough for condensation to form. 

Air temperature and surface temperature are not the same thing. 

Poor insulation and thermal bridging can create isolated problem areas even when the thermostat suggests everything is fine. 

Equally, overheating a property should not become the answer to another environmental issue. Excess Heat is an HHSRS Hazard. 

The aim should be a stable indoor environment where heating, insulation, moisture and airflow work together. 

People live differently. Weather changes. Heating patterns change. 

A good environmental solution should support the property, rather than relying on the occupant to constantly support the solution

4. Indoor air quality: think beyond the surfaces

We still tend to judge the condition of a property by what we can see. 

Is there mould on the wall? Does it look clean? Is the bathroom dry? 

Those observations matter, but they do not tell us everything about the indoor environment. 

A home can look clean and still have poor indoor air quality. 

Depending on the property, indoor air can contain mould spores, fine particulates, allergens, VOCs and combustion-related pollutants. 

This is where I think the sector will increasingly move towards measurement rather than assumption. 

An inspection gives you a snapshot. Environmental monitoring can tell you what is happening over time. Temperature, humidity and other data can help landlords understand how a property performs during colder weather, overnight and under normal occupation. 

But there is an important difference: 

Monitoring tells you what is happening. Intervention changes what is happening. 

The two should increasingly work together. 

Technology such as ArcAirTech’s can now operate continuously in occupied homes, supporting healthier indoor conditions in the background. 

That should never replace fixing leaks, insulation defects, heating issues or poor ventilation. 

But once those fundamentals have been addressed, it makes sense to ask how that improved environment can be actively maintained. 

5. Don't just repair it - protect the repair

This is probably the biggest change in mindset I would encourage. 

The traditional process is: 

Complaint → inspect → repair → close the job. 

For damp and mould, I prefer: 

Report → investigate → resolve → verify → monitor → protect. 

Landlords can spend significant sums repairing water ingress, upgrading ventilation, improving insulation, treating mould and redecorating. Once that work is complete, simply waiting to see whether the problem returns feels like a missed opportunity. 

The absence of visible mould does not necessarily mean the conditions that caused it have disappeared permanently. 

Winter arrives. Occupancy changes. Furniture moves. Heating patterns change. Moisture levels rise. 

That is why verification matters. 

It could be as simple as checking temperature and humidity, confirming ventilation is working, revisiting previously affected areas and speaking to the tenant. 

For more difficult or recurring cases, environmental monitoring or independent testing may also be useful. But I would take the principle one step further: 

Once you've created a healthy indoor environment, think about how you protect it. 

ArcAirTech’s active environmental technology can provide another layer of protection alongside good insulation, effective heating, suitable ventilation and proper building maintenance. 

Not as a substitute for any of those things. 

As protection for the investment already made in them. 

If a landlord has spent thousands resolving a recurring damp and mould issue, the objective should not simply be to wait and see whether it returns.It should be to reduce the likelihood of recurrence, understand when conditions start to change and intervene earlier. 

For me, that is the direction landlords should be moving towards: 

Don't just react. Investigate. Resolve. Verify. Then protect.