The draughts you have not chosen

Draughts are uncontrolled air movement through gaps you have not chosen - around ageing windows, skirting boards, letterboxes, and poorly fitted windows. In older properties especially, air moves freely through these gaps, pulling warm air out and letting cold air in. Most homeowners notice it as a persistent chill near windows or along floors, even when the heating is on.

Draught-proofing these gaps is one of the most effective and affordable things you can do. But there is an important distinction between sealing unwanted draughts and blocking all airflow, which brings me to ventilation.

Why sealing everything up can make things worse

Older buildings have been breathing through their gaps for decades. The air coming through those draughty windows and doors was not just losing heat - it was also carrying away moisture and bringing in fresh air. If you seal up a building with better-performing windows and add insulation without providing controlled ventilation elsewhere, you are not making the home safer. You are making the moisture problem invisible until it reappears as mould.

The goal is not a sealed box. It is a building where air comes in and out on your terms. Mechanical ventilation, passive vents, and trickle vents all have a role to play. This is especially important if you are planning any insulation work - ventilation needs to be considered at the same time, not as an afterthought.

You are not making the home safer. You are making the moisture problem invisible until it reappears as mould.

Insulation that works with your home

If your house has solid walls, they need to maintain their breathability. That means using breathable insulation materials - wood fibre and lime plaster rather than materials that trap moisture inside the wall. With cavity walls, the first step is investigating what is already in the cavity and what condition it is in before specifying anything new.

Mineral wool is cost-effective and lets moisture vapour pass through, but it needs to stay dry to perform. Cellulose handles moisture well and works in floors and roofs. Spray foam is one I would not recommend for older houses - it bonds to the structure, traps moisture, prevents inspection of timbers, and is extremely difficult to remove. For solid-wall properties, I generally choose wood fibre or rock wool for internal wall insulation because they are breathable, robust, and well-supported by moisture modelling data.

Get more from your existing heating

Before considering a new heating system, it is worth looking at what your current setup can do with better controls. Older properties often have a single heating zone, a basic thermostat, and no weather compensation. Adding thermostatic radiator valves (TRVs) to control individual rooms, a smart controller with load compensation, and weather compensation to an existing gas boiler can make a noticeable difference to how warm the house feels - at a fraction of the cost of replacing the whole system. Heating at a steady lower temperature is also more efficient and more comfortable than blasting high temperatures intermittently.

When a heat pump makes sense - and when it does not

The main challenge with heat pumps in older properties is the flow temperature. A standard pre-1980s central heating system is typically designed for a 70 to 80 degree flow, which suits a gas boiler. Heat pumps operate most efficiently at 35 to 45 degrees, meaning your existing radiators are likely undersized. You would either need to upsize them or accept reduced efficiency.

A well-insulated older house with upgraded radiators can work well with an air source heat pump. But dropping one into an uninsulated property with original radiators and expecting it to perform is not realistic - the heat is lost through the fabric faster than the system can replace it, resulting in higher electricity bills rather than savings.

Start with understanding, not products

The homeowners I find hardest to help are those who have already decided they need maximum insulation everywhere and are now wondering why they have condensation on the windows and a musty smell. You do not need the thickest or most insulation. You need to understand how your home currently manages moisture, where the heat is going, and what the structure can tolerate.

A good retrofit starts with a whole-house assessment, not a shopping list. And sequencing matters as much as the measures themselves - you always need to have ventilation sorted before a building becomes more airtight.

What to do next

If your house is cold and you are not sure where to start, book a free call to talk through your situation. We will help you understand your options and work out the right next step.