We are not going to give you a percentage, and you should be wary of anyone who does. What can be said with confidence is more useful than a number anyway.
This question invites a percentage, and there is no shortage of websites willing to supply one. We are not going to, for a straightforward reason: it depends on the property, the local market, what the roof was like before, and what else the house needs. Any firm figure is being invented.
That is not a dodge, because there are several things that can be said with confidence, and together they are more useful than a number.
Start here, because it is where the evidence actually is.
A roof visibly at the end of its life is something a surveyor will comment on whether or not it is currently leaking. Phrases like “nearing the end of its serviceable life” are meaningful, and once they are in a report they become a negotiating point.
Buyers then deduct — and they typically deduct more than the work would have cost. There are two reasons for that. First, they are estimating without knowing what is under the covering, so they price the worst case. Second, it is leverage, and they know it.
This is the part that is concrete rather than speculative, and it is worth more than people expect.
A folder of repair invoices does the opposite. It documents a history of problems without documenting a solution.
The roof is usually the largest single surface on a house and visible from further away than anything else. Decades of patch repairs leave it speckled — replacement units in different shades, tiles from three ranges, a mortar repair here, a mastic smear there. Uniformity is a substantial part of what a new roof buys, and kerb appeal is real even if it is hard to quantify.
Where the threshold is crossed, a replacement brings the roof up to current standards. On older property with original or minimal insulation that is a genuine improvement in how the house performs, and it shows up in an EPC as well as in the heating bill.
This is probably the largest effect and the hardest to measure. A buyer choosing between two similar houses, one of which needs a roof, does not usually negotiate — they buy the other one. Removing a major deferred maintenance item widens the pool of people willing to proceed.
In the interest of being straight about it:
| Situation | Usually the sensible answer |
|---|---|
| Roof at the end of its life, selling within a year | Replace — buyers deduct more than it costs |
| Roof at the end of its life, staying put | Replace, and take the thermal upgrade with it |
| Roof middle-aged, sound, selling soon | Leave it; spend elsewhere |
| Roof sound, staying put | Leave it |
| Repeated repairs, no single cause | Replace — the running total is already against you |
| One identifiable defect | Repair it properly |
If you are asking this question because you are thinking of selling, the useful thing we can do is look at the roof and tell you honestly whether it is something a surveyor would comment on. That is a much more actionable answer than a percentage.
And if the roof has years left in it, we will say so — which is not the answer that sells roofs, but it is the one that is true.
Two systems, and they are separate. Planning: a like-for-like re-roof does not materially affect the external appearance of a building, so under section 55 of the Town and Country Planning Act 1990 it is not development at all and needs no permission. A visible change of covering can be a different matter, particularly inside a conservation area.
Building regulations: where more than 50% of the roof's surface area is renewed, or the work forms part of a major renovation, regulation 23 of the Building Regulations 2010 requires the roof to be brought up to current thermal standards so far as that is technically, functionally and economically feasible. A patch repair does not trigger it, and neither does a roof over unheated space such as a detached garage. The work is signed off through building control or by a roofer registered under a competent person scheme, and you should receive a certificate.
We will tell you honestly whether the roof is something a surveyor would comment on, and what it would take to deal with it.
Complete new roofs, re-roofing and roof replacement across Chester, the Wirral, Deeside and the surrounding areas.
Tell us about the property and the roof, and we will come back to you — usually the same day.
Prefer to talk? Call 07464 259566 · WhatsApp 0044 7464 259566 · Email Evensbuddy@yahoo.com