Underfloor heating or insulation: which is best?
- Tom Collings
- May 16
- 4 min read
Updated: Aug 19
If your home has suspended timber floors, you might be wondering whether you should invest in underfloor heating, underfloor insulation - or both. At Retrovive, we specialise in professional underfloor insulation, helping homeowners make smarter choices for comfort, sustainability, and energy savings.
The truth is, in many cases, a well-insulated floor eliminates the need for underfloor heating altogether. Here’s why!
The Temptation of Underfloor Heating (and Its Hidden Costs)
Underfloor heating sounds appealing: a warm floor beneath your feet, especially in winter, seems like the ultimate comfort. But when it comes to retrofitting underfloor heating into a home with suspended timber floors, the picture gets more complicated:
Raised floor levels: Adding an electric or water-based underfloor heating system on top of existing flooring raises the floor level significantly - sometimes by 25–35mm or more. This can lead to clearance issues with doors and skirting boards, turning a small job into a complicated one.
Complex installation: Installing underfloor heating typically requires floorboards to be lifted, or in some cases, the entire floor reconstructed.
High running costs: Electric underfloor heating is much more expensive to run than gas-powered central heating. Even water-based systems (especially when paired with a heat pump) don’t necessarily reduce heating bills.
Slow heat-up times: Compared to radiators, underfloor heating takes longer to warm up a room, meaning it may not be as responsive when you need quick warmth.
Underfloor heating: the options explained
Electric Underfloor Heating Systems for Suspended Floors
Electric underfloor heating is the thinnest option, using a heating mat installed over a thin layer of insulation and topped with engineered boarding or chipboard, with the floor covering on top. However, even the slimmest system needs insulation (10mm), heating mat (2mm), perforated underlay (2mm) and engineered boarding (14mm) - together raising the floor level by 25–30mm or more.
Despite this, additional insulation is still needed to prevent heat loss through the ventilated void beneath suspended timber floors. Otherwise, that expensive heat is disappearing straight outside! This typically requires lifting floorboards or accessing the space from below.
Electric heating is significantly more expensive to run than gas, costing around four times as much per unit of energy. Plus, finishing touches like beading or skirting adjustments are often required to cover gaps around the room’s edges arising from the new floor height, and doors will need to be removed and shortened to clear the floor.
Water-Based Underfloor Heating Systems for Suspended Floors
Water systems use a long run of plastic pipe which is coiled many times up and down across the room. These pipes themselves add around 20mm in height and they are typically overlaid with 14mm engineered boards. However, with just this there is no insulation, at all, so to prevent the heat disappearing into the cold ventilation gap below the floor a 50mm (ideally) layer of insulation needs to be installed before the heating pipes are laid down.
To maintain the original floor height some systems place the heating pipes and the insulation between the floor joists, cutting the joists as necessary for pipework. This is a labour-intensive job requiring removal of all the floorboards along with the necessary plumbing installation.
Water-based underfloor heating is zoned into areas from a manifold somewhere in the house. Where it is mixed with radiators in different parts of the house a blending valve controls the different high and low water temperatures. While water-based underfloor heating works well with low-temperature heat sources like heat pumps, it doesn’t necessarily provide more heat than traditional radiators and is slower to warm up a cold home.
The Power of Proper Underfloor Insulation
Whether a home is heated by underfloor heating or radiators, there is always a need for insulation!
At Retrovive, we focus exclusively on what actually makes the biggest difference to warmth and efficiency: insulating the floor from below. Here's what proper underfloor insulation achieves:
✅ Reduces heat loss through the ventilated void beneath suspended timber floors;
✅ Blocks cold draughts, improving overall comfort;
✅ Lowers energy bills by making your existing heating system more effective;
✅ Preserves floor height, avoiding disruptive alterations to doors or skirting; and
✅ Minimises environmental impact by reducing unnecessary energy consumption.
When your floor is properly insulated, you simply need less heating. Many Retrovive customers find that their existing radiators work more than adequately once underfloor insulation is in place.
Why Choose Retrovive for Underfloor Insulation?
We’re specialists in retrofitting floor insulation for older homes across the UK. Unlike some providers who focus on underfloor heating systems, we’ve honed our expertise to deliver one thing exceptionally well: making your home warmer, more comfortable, and more efficient by upgrading what’s beneath your feet.
Key Feature | Underfloor Heating (Electric/Water) | Retrovive underfloor insulation |
Floor Height Change | Raises floor by 25-35mm or more | No change to floor height |
Installation Disruption | Significant (lifting floors, adding insulation below) | Minimal (only a few boards lifted) |
Energy Use | High (especially electric systems) | No energy used (lots of energy saved) |
Draught Proofing | No (unless insulation is also installed) | Yes (draught proofing is important for comfort) |
Need for multiple trades | Yes (plumbing or electrical work) | No (Retrovive is often installed in a day) |
Our service includes:
Comprehensive assessment of your suspended timber floors and a free quote service;
High-performance insulation fitted between floor joists;
Minimal disruption during installation;
Clear and honest advice about what will bring the best value to your home.
Underfloor Heating vs Underfloor Insulation: What’s Right for Your Home?
If you're building a new home, underfloor heating might make sense as part of a broader heating strategy. But for existing homes with suspended timber floors, underfloor insulation is the most effective and affordable upgrade.
Once a good layer of insulation is installed under the floor, it will naturally feel warmer - with much less heat needed to make the whole room warm and comfortable.
In most retrofit cases, underfloor heating adds unnecessary complexity and cost, with little added benefit.
Comfort, Efficiency, and Sustainability - From the Ground Up
Ready to make your home warmer and more energy-efficient without the downsides of underfloor heating? Let Retrovive help you insulate under your floors the right way.
📞 Contact the Retrovive team today for a no-obligation consultation and start saving on your energy bills while enjoying a cosier home.
