It’s complicated to achieve. 

Thanks to the vagaries of the UK housing market, the run-down 1950s semi my wife and I bought in the early 1990s now stands within football-kicking distance of a Conservation Area where prices bid goodbye to the million-pound mark some years ago.

To be accurate, our house has always remained pretty much the same distance from these properties, give or take the odd subsidence (we live on a clay hill). They remain, however, an impressive mix of Edwardian, Arts and Crafts and inter-war architectural styles with conspicuous kerb appeal.

Even with good draughtproofing, loft insulation and an insulated suspended ground floor most of these properties are likely to be very efficient wasters of heat.

But even the most expensive is almost certainly built from single-leaf brickwork. It also has either single glazing or specialised Conservation Area slimline double glazing, which can be designed more for aesthetics than performance.

The result is that even with good draughtproofing, loft insulation and an insulated suspended ground floor most of these properties are likely to be very efficient wasters of heat.

This may not overly concern anyone who can afford a million-pound-plus property, even with the increase in gas prices promised for this winter. But Britain has Europe’s highest proportion of houses built before World War II - some 38 per cent. Many, like my local Conservation Area properties, have walls of solid brick or stone with no insulation. 

For anyone planning to renovate an older home - and older homes still remain more popular than new builds in the UK - it’s the walls that present the biggest challenge. Those with cavities still unfilled can be insulated, typically with blown mineral wool fibres or polystyrene beads. But those without are obliged to add insulation, either to the outside of the house or to the interior.

Exterior insulation is the most effective because it encloses the entire house in a giant ‘tea cosy’ retaining as much heat as possible. Unfortunately, it also conceals the period features which make the house so appealing in the first place. And that’s assuming the local planning authority will approve such a dramatic change. 

The alternative is to insulate the exterior walls from the inside, though this will reduce the size of the rooms and still allow heat to escape through inaccessible areas. 

To make the UK net zero by 2050 the government wants to phase out domestic gas central heating for all new homes by 2025.

But do you really have to be so obsessive about heat loss? No one wants to pay higher fuel bills than necessary, but the gas that heats over 80 per cent of UK homes is still relatively cheap. At least, for the moment.

Which is the catch. To make the UK net zero by 2050 the government wants to phase out domestic gas central heating for all new homes by 2025. But a Heat and Buildings Strategy, promised for this autumn, may also announce a cut-off date for installing gas boilers in existing homes. 

The favoured alternative is a heat pump, a kind of reverse refrigerator which extracts heat from the air or the ground. The government’s aim is to fit 600,000 a year by 2028. But there are several hurdles to overcome. 

1 Heat pumps are much costlier than gas boilers, from £8,000 upwards for air source heat pumps which can simply be attached to the side of a house, and £20,000+ for more efficient ground source units; these need large amounts of buried pipework and the space to bury them in.

2 Heat pumps are most efficient at producing temperatures between 35°C and 45°C, ideal for underfloor heating but not for standard-sized radiator systems which require temperatures of up to 75°C. Extra-large radiators can compensate for this, but to cope with the higher flow rate needed for lower temperature systems, pipework may need to be upgraded from the 8mm to 10mm common in gas systems to a minimum of 22mm. A disruptive and expensive process.

3 Unlike gas boilers, which give blasts of heat on demand, heat pumps operate continuously, slowly building up warmth. To retain it, you need not just a well-insulated home but also a thermal store - a large hot water cylinder, ensuring warmth and hot water are always available. Bigger properties may even need an additional buffer tank. So no more wall-hung, cylinder-free combis.

Eco-minded renovators may be more likely to choose heat pumps over gas for ecological reasons. But the government will need carrots and sticks to persuade most UK homeowners. 

Current ideas include generous green grants, gas boiler scrappage schemes, levies on natural gas bills and reductions to electricity costs. 

James Standley of Kensa Heat Pumps suggests local ground source heat pump networks where low temperature water is pumped into houses, replacing the gas grid. Smaller, cheaper individual heat pumps then raise its temperature for heating and hot water.

But with only one per cent of UK homes currently using heat pumps these are early days. As the market grows, prices will fall and efficiencies are likely to increase. Heat pumps are widely used across northern Europe and Canada. 

In America a recent report found that a heat pump installation added seven per cent to the value of a home. In Britain’s excitable housing market that might be the biggest incentive of all.