Quick answer: For a loft with little or no insulation, it is usually one of the more worthwhile improvements you can make to a house. The Energy Saving Trust says around a quarter of the heat in an uninsulated home can be lost through the roof. How worthwhile it is for you depends on how much insulation you already have, its condition, the type of loft, and how you heat and use your home.
We won't give you a savings figure here, because any honest number depends on your house, your heating and your energy prices. What we can do is explain the things that make the difference, so you can judge it for yourself.
Why the roof matters
Heat moves from warm to cold, and warm air rises. In winter, the ceiling below your loft separates heated rooms from a cold roof space. Without a good layer of insulation, heat passes steadily through that ceiling and out of the roof. A proper layer of mineral wool slows that down, so the rooms below hold their warmth for longer.
What decides whether it is worth it for you
1. How much insulation you already have
This is the biggest factor. A loft with nothing, or with a thin old layer, has the most to gain. A loft that already has a good, even 270mm of dry insulation has very little to gain from more. Our guide on how thick loft insulation should be shows you how to measure it.
2. The condition of what is there
Depth on its own is not the whole story. Insulation that is damp, crushed under boxes, patchy, or soiled by rodents performs far below its thickness. Sometimes the worthwhile job is not adding more but taking the old material out and starting again. Our loft insulation removal service covers that.
3. How you heat the home
If you keep the house warm for long periods, more heat is escaping through a poorly insulated roof, so there is more to gain. If some rooms are rarely heated, the benefit is smaller, though cold upstairs rooms are often the first thing people notice improving.
4. The type of loft
A simple, accessible loft with standard joists is quick to insulate well. A loft with a very low pitch, awkward access, a room in the roof, or lots of stored belongings can take more work. That affects the cost side of the decision, which is why every job starts with an assessment.
5. Whether you want storage
If you need the loft for storage, the insulation has to be protected under raised boarding, otherwise boards laid straight on the joists will crush it. That adds to the job but keeps both the insulation and the storage working. See can you board over loft insulation?
6. Problems that need fixing first
Roof leaks, signs of mice or rats, or existing condensation need sorting before new insulation goes in. Insulating over a problem doesn't fix it, and can make it harder to spot later.
Benefits beyond the heating bill
- More comfortable rooms. Upstairs rooms tend to feel less chilly in winter.
- Less heat escaping through the ceiling in summer, too. Insulation slows heat moving in either direction, which can help top-floor rooms on hot days.
- A chance to check the loft. Getting someone up there often turns up things worth knowing about, such as a slipped tile, unlagged pipes or signs of pests.
When it may not be worth it
We would rather tell you not to bother than sell you work you don't need. It is unlikely to be worthwhile if:
- you already have around 270mm of dry, even mineral wool in good condition;
- the space is already a converted room insulated at the rafters;
- there is a roof or damp problem that has to be fixed first (in which case fix that, then insulate).
Questions to ask before you go ahead
- How deep is the insulation now, and in what condition? A good installer should measure it and tell you, not guess.
- Will anything be removed? If so, why, and where will it go?
- What happens at the eaves, hatch and pipes? These details are where a loft job is done well or badly.
- What is in the written quotation? It should list the scope, the materials and the price, so you can compare like with like.
What about the cost?
The price depends on the size of the loft, how much insulation is already there, whether anything needs removing, access, and whether you want boarding or a loft ladder added. Our loft insulation cost page explains these factors, and the written quotation you get after the assessment shows the exact scope and price. Some households may also qualify for help through government-backed schemes: our loft insulation grants guide explains what to check on GOV.UK first.
How to find out for your home
The simplest way to know is to have someone look. On a free assessment we measure what you have, check its condition, look at ventilation and access, and tell you plainly whether a top-up, a replacement or nothing at all makes sense. You can read more about our approach to loft insulation, and we cover homes across Teesside and the North East.
Every job starts with a free assessment and a written quotation that sets out the scope, materials and price before anything is agreed. The work is carried out by The Insulation Company or an approved installation partner. Call 0800 229 4668 (Monday to Saturday, 8am to 6pm) or request your free assessment online.