Your house may still feel cold with the heating on because heat is escaping faster than your heating system can replace it. In homes across Horley, Reigate, Redhill, Crawley, Surrey, and West Sussex, this is often caused by heat loss, draughts, poor insulation, undersized radiators, heating control issues, or problems with the building fabric.
This guide explains the most common reasons a home feels cold even when the heating is running, what you can check, and when a proper heat loss survey or energy performance assessment may be useful.
We’ll cover:
- Why your home may still feel cold
- How heat loss affects comfort
- Common draught and insulation problems
- Why some rooms are colder than others
- How heating controls affect warmth
- Whether your radiators may be undersized
- How windows, doors, floors, and lofts affect comfort
- How EPCs and heat loss surveys can help
- Common mistakes to avoid
- What to do before spending money on upgrades
- How JPEC Building Services can help
Why does my house feel cold even with the heating on?
A house usually feels cold with the heating on because the heat being produced is not staying inside the property for long enough. The heating may be working, but the building may be losing warmth through weak points.
This does not always mean the boiler, radiators, or heating system is broken. In many cases, the issue is a combination of heat loss, draughts, poor insulation, cold surfaces, and heating controls that are not set up well.
For example, an older home in Reigate or Redhill may have solid walls, suspended timber floors, older glazing, and loft insulation that is not performing as well as expected. A newer home in Crawley or Horley may still feel uncomfortable if there are gaps in insulation, poor controls, or rooms that are not balanced properly.
The key is to understand whether the problem is the heating system, the building, or both.
What is heat loss?
Heat loss is the process of warmth escaping from your home through the walls, roof, floors, windows, doors, draughts, and ventilation. In simple terms, it is the reason your home cools down.
Every property loses heat. The issue is how quickly it happens.
If your home loses heat quickly, your heating system has to work harder to maintain a comfortable temperature. This can lead to higher running costs, colder rooms, uneven heating, and frustration because the house never feels properly warm.
A heat loss survey can help identify where heat is escaping and how much heat each room may need. JPEC Building Services can carry out heat loss surveys and explain the findings in plain English, helping you understand what is likely to make the biggest difference.
Could draughts be making your home cold?
Yes, draughts are one of the most common reasons a home feels cold even when the heating is on. Cold air entering the property can make rooms feel uncomfortable and can cause the heating to work harder.
Draughts often appear around windows, doors, floorboards, loft hatches, fireplaces, service penetrations, and gaps around pipework. In older homes across Surrey and West Sussex, draughts can be especially noticeable because building standards and construction methods have changed over time.
Common draught sources include:
- gaps around external doors
- poorly sealed windows
- open chimneys or fireplaces
- unsealed loft hatches
- gaps between floorboards
- pipework or cable entry points
- poorly sealed extensions or conversions
Reducing draughts can help, but it should be done carefully. Homes still need proper ventilation to manage moisture, indoor air quality, and condensation risk.
Could poor insulation be the problem?
Poor insulation can make a major difference to how warm your home feels. If insulation is missing, thin, damaged, or poorly fitted, heat can escape quickly even when the heating is running.
Loft insulation is often one of the first areas to check because warm air rises. If the loft is poorly insulated, a lot of heat can be lost through the roof.
Walls and floors can also matter. Solid walls, uninsulated cavity walls, suspended timber floors, and poorly insulated extensions can all make rooms feel cold.
Building fabric means the physical parts of the property, such as the walls, roof, floors, windows, doors, and insulation. If the building fabric is weak, heating upgrades alone may not solve the comfort problem.
JPEC Building Services can help assess building fabric and explain where further inspection, heat loss calculations, or energy performance advice may be useful.
Why are some rooms colder than others?
Some rooms are colder than others because they may lose more heat, receive less heat, or have different construction details. A cold room is not always caused by the same issue as the rest of the house.
A room may be colder because it has more external walls, a flat roof, poor insulation, a small radiator, draughty windows, limited airflow, or a colder floor. Extensions, conservatories, loft conversions, and rooms above garages can be especially prone to temperature differences.
For example, a kitchen extension in Redhill may lose heat differently from the original part of the house. A bedroom above a garage in Crawley may feel colder because the floor below is unheated. A living room in an older Reigate property may have cold walls and draughts around the fireplace.
A room-by-room heat loss assessment can help identify why certain spaces are harder to heat.
Could your heating controls be set up badly?
Yes, heating controls can make a home feel colder or less comfortable if they are not set up properly. Even a good heating system can perform poorly if the controls do not suit the way the property is used.
Thermostats, programmers, radiator valves, zoning, and timers all affect comfort. If the thermostat is in the wrong place, it may switch the heating off before colder rooms have warmed up. If radiator valves are not adjusted properly, some rooms may overheat while others remain cold.
Zoning means dividing the heating into different areas, so each part of the property can be controlled more appropriately.
For larger homes, rental properties, or properties with extensions, controls can make a noticeable difference. However, controls should not be used to hide underlying problems such as poor insulation, draughts, or undersized radiators.
Are your radiators too small?
Your radiators may be too small if they cannot deliver enough heat to match the room’s heat loss. This can leave a room feeling cold even when the heating is on.
Radiators are sometimes undersized because a room has been extended, insulation has changed, windows have been replaced, or the heating system was never designed accurately in the first place. In some cases, the radiator may be the right size, but sludge, trapped air, poor balancing, or low system temperatures may reduce performance.
This matters even more if you are considering a heat pump. Heat pumps usually work at lower flow temperatures than traditional boilers. Flow temperature means the temperature of the water going from the heating system into your radiators or underfloor heating.
A heat loss calculation can help identify how much heat each room needs and whether the existing radiators are likely to be suitable.
Can windows, doors, and floors make a house feel cold?
Yes, windows, doors, and floors can make a house feel cold because they affect both heat loss and how comfortable the room feels. Cold surfaces can make you feel chilly even when the air temperature seems reasonable.
Older glazing, poorly sealed doors, and uninsulated floors can all contribute to discomfort. Suspended timber floors can be draughty if cold air moves beneath the floorboards. Large areas of glass can also make rooms feel cooler, especially in the evening or during winter.
This does not always mean you need to replace everything. Sometimes sealing gaps, improving insulation, adjusting heating design, or dealing with specific weak points may be more practical.
A proper assessment helps avoid jumping to expensive solutions before the real cause is understood.
How can an EPC help if your home is cold?
An EPC can help by giving you a general view of your home’s energy performance and possible improvements. EPC stands for Energy Performance Certificate, which rates a property’s energy efficiency from A to G.
An EPC may recommend improvements such as insulation, heating controls, more efficient heating, or renewable technologies. For landlords, EPC performance can also affect compliance when renting out a property.
However, an EPC is not the same as a heat loss survey. It gives useful energy performance information, but it does not always explain why one room is cold or whether your heating system is sized correctly.
JPEC Building Services can support EPC surveys and help explain how the result relates to comfort, running costs, and future improvement options.
When is a heat loss survey worth it?
A heat loss survey is worth considering if your home feels cold, loses warmth quickly, has uneven room temperatures, or you are planning heating or insulation upgrades. It is especially useful before spending money on major improvements.
A heat loss survey can help if:
- your heating is on but rooms still feel cold
- your energy bills seem high
- some rooms are much colder than others
- you are considering a heat pump
- you are planning insulation upgrades
- you want to understand comfort problems properly
- you are improving an older or extended property
For homes across Horley, Reigate, Redhill, Crawley, Surrey, and West Sussex, this kind of assessment can help turn a vague comfort problem into practical next steps.
JPEC Building Services can assess, survey, calculate, report, and advise properly, helping you understand what is likely to matter most.
What mistakes should you avoid?
The biggest mistake is spending money on upgrades without understanding why the house is cold. If you guess the cause, you may fix the wrong problem.
Common mistakes include:
- replacing the heating system before checking heat loss
- assuming bigger radiators will solve every issue
- adding insulation without considering ventilation
- ignoring draughts
- relying only on smart controls
- assuming all cold rooms have the same cause
- installing a heat pump without a heat loss survey
- treating EPC recommendations as a full design
- ignoring building condition issues
A balanced approach is usually best. The heating system, insulation, ventilation, controls, and building fabric all need to be considered together.
What should you do before spending money on upgrades?
Before spending money, start by understanding the problem. A proper assessment can help identify whether the issue is heat loss, heating design, draughts, insulation, controls, or a combination of factors.
You can begin by noting which rooms feel cold, when they feel cold, whether the problem is worse in windy weather, how quickly rooms cool down, and whether there are signs of condensation, draughts, or cold surfaces.
It is also useful to gather information about the property, such as previous EPCs, insulation details, heating system information, extension records, or window and door upgrades.
JPEC Building Services can help homeowners, landlords, developers, and commercial clients across Surrey and West Sussex understand the building first, then consider the most suitable next steps.
Can this support future improvements such as heat pumps or solar panels?
Yes, understanding why your home is cold can support future improvements such as heat pumps, insulation upgrades, EPC improvements, and wider energy performance planning. It can also help you avoid installing new technology into a building that has not been properly assessed.
If you are considering a heat pump, a heat loss survey is particularly important because the heating system needs to be designed around the property’s heat demand.
If you are considering solar panels or battery storage, the cold-house issue may not be directly solved by solar, but a wider energy assessment can help you plan improvements in the right order.
As part of the wider JPEC Group, JPEC Building Services can help connect assessment, compliance, design, and delivery where appropriate.
JPEC Building Services can help
JPEC Building Services are experienced local building compliance, energy performance, surveying, and sustainability specialists supporting homeowners, landlords, developers, commercial clients, and business owners across Horley, Reigate, Redhill, Crawley, Surrey, West Sussex, and surrounding areas.
They can help assess, survey, calculate, report, advise, and support you properly, whether you need a heat loss survey, EPC survey, condition report, roof survey for solar suitability, sustainability report, decarbonisation report, SAP calculation, Predicted Energy Assessment, or wider compliance support.
As part of the wider JPEC Group, JPEC Building Services can help connect assessment, compliance, design, and delivery where appropriate. The aim is to explain trade-offs, comfort issues, building suitability, energy performance, likely improvements, compliance requirements, and practical next steps in plain English.
This article is general information only and is not personal advice. Recommendations should always be confirmed through a proper survey, inspection, assessment, calculation, or system design for the individual property and requirements.
